GitHub/exynos8895/android_kernel_samsung_universal8895.git
2 years agozram: close udev startup race condition as default groups
Minchan Kim [Fri, 23 Nov 2018 06:30:06 +0000 (15:30 +0900)]
zram: close udev startup race condition as default groups

commit fef912bf860e upstream.
commit 98af4d4df889 upstream.

I got a report from Howard Chen that he saw zram and sysfs race(ie,
zram block device file is created but sysfs for it isn't yet)
when he tried to create new zram devices via hotadd knob.

v4.20 kernel fixes it by [1, 2] but it's too large size to merge
into -stable so this patch fixes the problem by registering defualt
group by Greg KH's approach[3].

This patch should be applied to every stable tree [3.16+] currently
existing from kernel.org because the problem was introduced at 2.6.37
by [4].

[1] fef912bf860e, block: genhd: add 'groups' argument to device_add_disk
[2] 98af4d4df889, zram: register default groups with device_add_disk()
[3] http://kroah.com/log/blog/2013/06/26/how-to-create-a-sysfs-file-correctly/
[4] 33863c21e69e9, Staging: zram: Replace ioctls with sysfs interface

Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Hannes Reinecke <hare@suse.com>
Tested-by: Howard Chen <howardsoc@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2 years agoANDROID: zram: set comp_len to PAGE_SIZE when page is huge
Peter Kalauskas [Thu, 8 Nov 2018 19:03:13 +0000 (11:03 -0800)]
ANDROID: zram: set comp_len to PAGE_SIZE when page is huge

This bug was introduced when two patches were applied out of order.

* zram: drop max_zpage_size and use zs_huge_class_size()
* zram: mark incompressible page as ZRAM_HUGE

Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 119260394
Change-Id: I437d35c8d23c15237ad9c2d5bd7f99d7bff42872

2 years agoBACKPORT: zram: drop max_zpage_size and use zs_huge_class_size()
Sergey Senozhatsky [Thu, 5 Apr 2018 23:24:47 +0000 (16:24 -0700)]
BACKPORT: zram: drop max_zpage_size and use zs_huge_class_size()

Remove ZRAM's enforced "huge object" value and use zsmalloc huge-class
watermark instead, which makes more sense.

TEST
- I used a 1G zram device, LZO compression back-end, original
  data set size was 444MB. Looking at zsmalloc classes stats the
  test ended up to be pretty fair.

BASE ZRAM/ZSMALLOC
=====================
zram mm_stat

498978816 191482495 199831552        0 199831552    15634        0

zsmalloc classes

 class  size almost_full almost_empty obj_allocated   obj_used pages_used pages_per_zspage freeable
...
   151  2448           0            0          1240       1240        744                3        0
   168  2720           0            0          4200       4200       2800                2        0
   190  3072           0            0         10100      10100       7575                3        0
   202  3264           0            0           380        380        304                4        0
   254  4096           0            0         10620      10620      10620                1        0

 Total                 7           46        106982     106187      48787                         0

PATCHED ZRAM/ZSMALLOC
=====================

zram mm_stat

498978816 182579184 194248704        0 194248704    15628        0

zsmalloc classes

 class  size almost_full almost_empty obj_allocated   obj_used pages_used pages_per_zspage freeable
...
   151  2448           0            0          1240       1240        744                3        0
   168  2720           0            0          4200       4200       2800                2        0
   190  3072           0            0         10100      10100       7575                3        0
   202  3264           0            0          7180       7180       5744                4        0
   254  4096           0            0          3820       3820       3820                1        0

 Total                 8           45        106959     106193      47424                         0

As we can see, we reduced the number of objects stored in class-4096,
because a huge number of objects which we previously forcibly stored in
class-4096 now stored in non-huge class-3264.  This results in lower
memory consumption:

- zsmalloc now uses 47424 physical pages, which is less than 48787 pages
  zsmalloc used before.

- objects that we store in class-3264 share zspages.  That's why overall
  the number of pages that both class-4096 and class-3264 consumed went
  down from 10924 to 9564.

[sergey.senozhatsky.work@gmail.com: add pool param to zs_huge_class_size()]
Link: http://lkml.kernel.org/r/20180314081833.1096-3-sergey.senozhatsky@gmail.com
Link: http://lkml.kernel.org/r/20180306070639.7389-3-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 60f5921a9a4f126e081318bd6bb2bc2798b7bba8)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 113183619
Change-Id: I1d3ede25543e99a24802ad03f68995f33aaf79b5

2 years agoUPSTREAM: drivers/block/zram/zram_drv.c: fix bug storing backing_dev
Peter Kalauskas [Wed, 22 Aug 2018 04:54:02 +0000 (21:54 -0700)]
UPSTREAM: drivers/block/zram/zram_drv.c: fix bug storing backing_dev

The call to strlcpy in backing_dev_store is incorrect. It should take
the size of the destination buffer instead of the size of the source
buffer.  Additionally, ignore the newline character (\n) when reading
the new file_name buffer. This makes it possible to set the backing_dev
as follows:

echo /dev/sdX > /sys/block/zram0/backing_dev

The reason it worked before was the fact that strlcpy() copies 'len - 1'
bytes, which is strlen(buf) - 1 in our case, so it accidentally didn't
copy the trailing new line symbol.  Which also means that "echo -n
/dev/sdX" most likely was broken.

Signed-off-by: Peter Kalauskas <peskal@google.com>
Link: http://lkml.kernel.org/r/20180813061623.GC64836@rodete-desktop-imager.corp.google.com
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: <stable@vger.kernel.org> [4.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit c8bd134a4bddafe5917d163eea73873932c15e83)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I0a0d602b61169ae9adc8f89914ce4e30cc10e191

2 years agoBACKPORT: zram: introduce zram memory tracking
Minchan Kim [Fri, 8 Jun 2018 00:05:49 +0000 (17:05 -0700)]
BACKPORT: zram: introduce zram memory tracking

zRam as swap is useful for small memory device.  However, swap means
those pages on zram are mostly cold pages due to VM's LRU algorithm.
Especially, once init data for application are touched for launching,
they tend to be not accessed any more and finally swapped out.  zRAM can
store such cold pages as compressed form but it's pointless to keep in
memory.  Better idea is app developers free them directly rather than
remaining them on heap.

This patch tell us last access time of each block of zram via "cat
/sys/kernel/debug/zram/zram0/block_state".

The output is as follows,
      300    75.033841 .wh
      301    63.806904 s..
      302    63.806919 ..h

First column is zram's block index and 3rh one represents symbol (s:
same page w: written page to backing store h: huge page) of the block
state.  Second column represents usec time unit of the block was last
accessed.  So above example means the 300th block is accessed at
75.033851 second and it was huge so it was written to the backing store.

Admin can leverage this information to catch cold|incompressible pages
of process with *pagemap* once part of heaps are swapped out.

I used the feature a few years ago to find memory hoggers in userspace
to notify them what memory they have wasted without touch for a long
time.  With it, they could reduce unnecessary memory space.  However, at
that time, I hacked up zram for the feature but now I need the feature
again so I decided it would be better to upstream rather than keeping it
alone.  I hope I submit the userspace tool to use the feature soon.

[akpm@linux-foundation.org: fix i386 printk warning]
[minchan@kernel.org: use ktime_get_boottime() instead of sched_clock()]
Link: http://lkml.kernel.org/r/20180420063525.GA253739@rodete-desktop-imager.corp.google.com
[akpm@linux-foundation.org: documentation tweak]
[akpm@linux-foundation.org: fix i386 printk warning]
[minchan@kernel.org: fix compile warning]
Link: http://lkml.kernel.org/r/20180508104849.GA8209@rodete-desktop-imager.corp.google.com
[rdunlap@infradead.org: fix printk formats]
Link: http://lkml.kernel.org/r/3652ccb1-96ef-0b0b-05d1-f661d7733dcc@infradead.org
Link: http://lkml.kernel.org/r/20180416090946.63057-5-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit c0265342bff4fcaa2cdf13f4596244c18d4a7ae5)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I932447d33d1b6af78ae6463b494006c725e5e38c

2 years agoBACKPORT: zram: record accessed second
Minchan Kim [Fri, 8 Jun 2018 00:05:45 +0000 (17:05 -0700)]
BACKPORT: zram: record accessed second

zRam as swap is useful for small memory device.  However, swap means
those pages on zram are mostly cold pages due to VM's LRU algorithm.
Especially, once init data for application are touched for launching,
they tend to be not accessed any more and finally swapped out.  zRAM can
store such cold pages as compressed form but it's pointless to keep in
memory.  Better idea is app developers free them directly rather than
remaining them on heap.

This patch records last access time of each block of zram so that With
upcoming zram memory tracking, it could help userspace developers to
reduce memory footprint.

Link: http://lkml.kernel.org/r/20180416090946.63057-4-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit d7eac6b6e1838ef1a1400df4ec55daa34bbc855e)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I5b217d3cd4da57e548196658e0824d65a0cad631

2 years agoBACKPORT: zram: mark incompressible page as ZRAM_HUGE
Minchan Kim [Fri, 8 Jun 2018 00:05:42 +0000 (17:05 -0700)]
BACKPORT: zram: mark incompressible page as ZRAM_HUGE

Mark incompressible pages so that we could investigate who is the owner
of the incompressible pages once the page is swapped out via using
upcoming zram memory tracker feature.

With it, we could prevent such pages to be swapped out by using mlock.
Otherwise we might remove them.

This patch exposes new stat for huge pages via mm_stat.

Link: http://lkml.kernel.org/r/20180416090946.63057-3-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 89e85bce4b02edb7408aebf69d5d1a6692a05f4f)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: If1b7b2d6ea6672a575ffc3d70c2c8b58ecafd0d7

2 years agoUPSTREAM: zram: correct flag name of ZRAM_ACCESS
Minchan Kim [Fri, 8 Jun 2018 00:05:39 +0000 (17:05 -0700)]
UPSTREAM: zram: correct flag name of ZRAM_ACCESS

Patch series "zram memory tracking", v5.

zRam as swap is useful for small memory device.  However, swap means
those pages on zram are mostly cold pages due to VM's LRU algorithm.
Especially, once init data for application are touched for launching,
they tend to be not accessed any more and finally swapped out.  zRAM can
store such cold pages as compressed form but it's pointless to keep in
memory.  As well, it's pointless to store incompressible pages to zram
so better idea is app developers manages them directly like free or
mlock rather than remaining them on heap.

This patch provides a debugfs /sys/kernel/debug/zram/zram0/block_state
to represent each block's state so admin can investigate what memory is
cold|incompressible|same page with using pagemap once the pages are
swapped out.

The output is as follows:
      300    75.033841 .wh
      301    63.806904 s..
      302    63.806919 ..h

First column is zram's block index and 3rh one represents symbol (s:
same page w: written page to backing store h: huge page) of the block
state.  Second column represents usec time unit of the block was last
accessed.  So above example means the 300th block is accessed at
75.033851 second and it was huge so it was written to the backing store.

This patch (of 4):

ZRAM_ACCESS is used for locking a slot of zram so correct the name.  It
is also not a common flag to indicate status of the block so move the
declare position on top of the flag.  Lastly, let's move the function to
the top of source code to be able to use it easily without forward
declaration.

Link: http://lkml.kernel.org/r/20180416090946.63057-2-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit c4d6c4cc7bfd5ecc18548420b7fb9440cf8416ae)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I037a22a739fb4005918eb668d10e8be354a1524f

2 years agoUPSTREAM: zram: Delete gendisk before cleaning up the request queue
Bart Van Assche [Wed, 28 Feb 2018 18:15:30 +0000 (10:15 -0800)]
UPSTREAM: zram: Delete gendisk before cleaning up the request queue

Remove the disk, partition and bdi sysfs attributes before cleaning up
the request queue associated with the disk.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit 392db38058eb47250a9d0cc737af37e78a7e443d)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ifbcb6e03fee764054dc9a371c00b95547e4de745

2 years agoUPSTREAM: drivers/block/zram/zram_drv.c: make zram_page_end_io() static
Colin Ian King [Thu, 16 Nov 2017 01:37:08 +0000 (17:37 -0800)]
UPSTREAM: drivers/block/zram/zram_drv.c: make zram_page_end_io() static

zram_page_end_io() is local to the source and does not need to be in
global scope, so make it static.

Cleans up sparse warning:

  symbol 'zram_page_end_io' was not declared. Should it be static?

Link: http://lkml.kernel.org/r/20171016173336.20320-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 384bc41fc064bd8b12b7081aa3e81d26f3407045)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ie0f250e580bc1dd16e963b5dbe5bdc429fb4cd65

2 years agoBACKPORT: zram: set BDI_CAP_STABLE_WRITES once
Minchan Kim [Thu, 16 Nov 2017 01:32:56 +0000 (17:32 -0800)]
BACKPORT: zram: set BDI_CAP_STABLE_WRITES once

With fast swap storage, the platform wants to use swap more aggressively
and swap-in is crucial to application latency.

The rw_page() based synchronous devices like zram, pmem and btt are such
fast storage.  When I profile swapin performance with zram lz4
decompress test, S/W overhead is more than 70%.  Maybe, it would be
bigger in nvdimm.

This patchset reduces swap-in latency by skipping swapcache if the swap
device is a synchronous device like a rw_page() based device.

It enhances by 45% my swapin test (5G sequential swapin, no readahead)
from 2.41sec to 1.64sec.

This patch (of 4):

Commit 19b7ccf8651d ("block: get rid of blk_integrity_revalidate()")
fixed a weird thing (i.e., reset BDI_CAP_STABLE_WRITES flag
unconditionally whenever revalidat_disk is called) so zram doesn't need
to reset the flag any more when revalidating the bdev.  Instead, set the
flag just once when the zram device is created.

It shouldn't change any behavior.

Link: http://lkml.kernel.org/r/1505886205-9671-2-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hugh Dickins <hughd@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit e447a0151f7ce8dd884fea48279274bd64434c29)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: If41edc4871ed470f050bbf4d51a24fe5c0e18738

2 years agoUPSTREAM: zram: fix null dereference of handle
Minchan Kim [Tue, 3 Oct 2017 23:15:19 +0000 (16:15 -0700)]
UPSTREAM: zram: fix null dereference of handle

In testing I found handle passed to zs_map_object in __zram_bvec_read is
NULL so eh kernel goes oops in pin_object().

The reason is there is no routine to check the slot's freeing after
getting the slot's lock.  This patch fixes it.

[minchan@kernel.org: v2]
Link: http://lkml.kernel.org/r/1505887347-10881-1-git-send-email-minchan@kernel.org
Link: http://lkml.kernel.org/r/1505788488-26723-1-git-send-email-minchan@kernel.org
Fixes: 1f7319c74275 ("zram: partial IO refactoring")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit ae94264ed4b0cf7cd887947650db4c69acb62072)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I0ff4a8c2f1fcd0ee39511985809b58bf94b2d44c

2 years agoUPSTREAM: zram: add config and doc file for writeback feature
Minchan Kim [Wed, 6 Sep 2017 23:20:10 +0000 (16:20 -0700)]
UPSTREAM: zram: add config and doc file for writeback feature

This patch adds document and kconfig for using of writeback feature.

Link: http://lkml.kernel.org/r/1498459987-24562-10-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Juneho Choi <juno.choi@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 5a47074f0279421778f97b1b1e75686696a5f42a)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I9ec2230739a6468a4481a90a9c9f966badf9ac48

2 years agoBACKPORT: zram: read page from backing device
Minchan Kim [Wed, 6 Sep 2017 23:20:07 +0000 (16:20 -0700)]
BACKPORT: zram: read page from backing device

This patch enables read IO from backing device.  For the feature, it
implements two IO read functions to transfer data from backing storage.

One is asynchronous IO function and other is synchronous one.

A reason I need synchrnous IO is due to partial write which need to
complete read IO before the overwriting partial data.

We can make the partial IO's case asynchronous, too but at the moment, I
don't feel adding more complexity to support such rare use cases so want
to go with simple.

[xieyisheng1@huawei.com: read_from_bdev_async(): return 1 to avoid call page_endio() in zram_rw_page()]
Link: http://lkml.kernel.org/r/1502707447-6944-1-git-send-email-xieyisheng1@huawei.com
Link: http://lkml.kernel.org/r/1498459987-24562-9-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Juneho Choi <juno.choi@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 8e654f8fbff52ac483fb69957222853d7e2fc588)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ia82f5fc4697aacc723a336e4dad4e7bc56a1bdb9

2 years agoBACKPORT: zram: write incompressible pages to backing device
Minchan Kim [Wed, 6 Sep 2017 23:20:03 +0000 (16:20 -0700)]
BACKPORT: zram: write incompressible pages to backing device

This patch enables write IO to transfer data to backing device.  For
that, it implements write_to_bdev function which creates new bio and
chaining with parent bio to make the parent bio asynchrnous.

For rw_page which don't have parent bio, it submit owned bio and handle
IO completion by zram_page_end_io.

Also, this patch defines new flag ZRAM_WB to mark written page for later
read IO.

[xieyisheng1@huawei.com: fix typo in comment]
Link: http://lkml.kernel.org/r/1502707447-6944-2-git-send-email-xieyisheng1@huawei.com
Link: http://lkml.kernel.org/r/1498459987-24562-8-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Juneho Choi <juno.choi@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit db8ffbd4e7634cc537c8d32e73e7ce0f06248645)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ie675efd6c3ec04a151443f1cd0bf798d4847710f

2 years agoBACKPORT: zram: identify asynchronous IO's return value
Minchan Kim [Wed, 6 Sep 2017 23:20:00 +0000 (16:20 -0700)]
BACKPORT: zram: identify asynchronous IO's return value

For upcoming asynchronous IO like writeback, zram_rw_page should be
aware of that whether requested IO was completed or submitted
successfully, otherwise error.

For the goal, zram_bvec_rw has three return values.

-errno: returns error number
     0: IO request is done synchronously
     1: IO request is issued successfully.

Link: http://lkml.kernel.org/r/1498459987-24562-7-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Juneho Choi <juno.choi@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit ae85a8075c5b025b9d503554ddc480a346a24536)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Id6e764b3eacfebdca2f46050648a49fc5f276b2c

2 years agoBACKPORT: zram: add free space management in backing device
Minchan Kim [Wed, 6 Sep 2017 23:19:57 +0000 (16:19 -0700)]
BACKPORT: zram: add free space management in backing device

With backing device, zram needs management of free space of backing
device.

This patch adds bitmap logic to manage free space which is very naive.
However, it would be simple enough as considering uncompressible pages's
frequenty in zram.

Link: http://lkml.kernel.org/r/1498459987-24562-6-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Juneho Choi <juno.choi@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 1363d4662a0d28dfdb81ef426c88c9a8dbf7c338)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I37dc98b40bfddceb9eb6d989ca30683dbf89210c

2 years agoUPSTREAM: zram: add interface to specif backing device
Minchan Kim [Wed, 6 Sep 2017 23:19:54 +0000 (16:19 -0700)]
UPSTREAM: zram: add interface to specif backing device

For writeback feature, user should set up backing device before the zram
working.

This patch enables the interface via /sys/block/zramX/backing_dev.

Currently, it supports block device only but it could be enhanced for
file as well.

Link: http://lkml.kernel.org/r/1498459987-24562-5-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Juneho Choi <juno.choi@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 013bf95a83ec760a2afc37fabd6bf13a9cdae205)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I4bbf12ed7496d476bddd574e756bac5c8a838089

2 years agoUPSTREAM: zram: rename zram_decompress_page to __zram_bvec_read
Minchan Kim [Wed, 6 Sep 2017 23:19:50 +0000 (16:19 -0700)]
UPSTREAM: zram: rename zram_decompress_page to __zram_bvec_read

zram_decompress_page naming is not proper because it doesn't decompress
if page was dedup hit or stored with compression.

Use more abstract term and consistent with write path function
__zram_bvec_write.

Link: http://lkml.kernel.org/r/1498459987-24562-4-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Juneho Choi <juno.choi@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 693dc1ce25b8c8fa33f930d47cd8f926eeb90812)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ia7c948f4b78601458b7ebc23ab345d4bc0a8d4a8

2 years agoUPSTREAM: zram: inline zram_compress
Minchan Kim [Wed, 6 Sep 2017 23:19:47 +0000 (16:19 -0700)]
UPSTREAM: zram: inline zram_compress

zram_compress does several things, compress, entry alloc and check
limitation.  I did for just readbility but it hurts modulization.:(

So this patch removes zram_compress functions and inline it in
__zram_bvec_write for upcoming patches.

Link: http://lkml.kernel.org/r/1498459987-24562-3-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Juneho Choi <juno.choi@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 97ec7c8bd5d029b2c3e40355c1204197094e9ba1)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ibb37d77168edd0b01d0b9820e431c73cc3c2ff20

2 years agoUPSTREAM: zram: clean up duplicated codes in __zram_bvec_write
Minchan Kim [Wed, 6 Sep 2017 23:19:44 +0000 (16:19 -0700)]
UPSTREAM: zram: clean up duplicated codes in __zram_bvec_write

Patch series "writeback incompressible pages to storage", v1.

zRam is useful for memory saving with compressible pages but sometime,
workload can be changed and system has lots of incompressible pages
which is very harmful for zram.

This patch supports writeback feature of zram so admin can set up a
block device and with it, zram can save the memory via writing out the
incompressile pages once it found it's incompressible pages (1/4 comp
ratio) instead of keeping the page in memory.

[1-3] is just clean up and [4-8] is step by step feature enablement.
[4-8] is logically not bisectable(ie, logical unit separation)
although I tried to compiled out without breaking but I think it would
be better to review.

This patch (of 9):

__zram_bvec_write has some of duplicated logic for zram meta data
handling of same_page|compressed_page.  This patch aims to clean it up
without behavior change.

[xieyisheng1@huawei.com: fix compr_data_size stat]
Link: http://lkml.kernel.org/r/1502707447-6944-1-git-send-email-xieyisheng1@huawei.com
Link: http://lkml.kernel.org/r/1496019048-27016-1-git-send-email-minchan@kernel.org
Link: http://lkml.kernel.org/r/1498459987-24562-2-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Juneho Choi <juno.choi@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 4ebbe7f7fc99260afd51759e35dbfdd6010dc697)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I3fa150c869a66ff289712b956924ecb361864a2e

2 years agoUPSTREAM: zram: add zstd to the supported algorithms list
Sergey Senozhatsky [Thu, 16 Nov 2017 01:33:49 +0000 (17:33 -0800)]
UPSTREAM: zram: add zstd to the supported algorithms list

Add ZSTD to the list of supported compression algorithms.

ZRAM fio perf test:

                      LZO         DEFLATE         ZSTD

WRITE:              (2180MB/s)   (77.2MB/s)      (1429MB/s)
WRITE:              (1617MB/s)   (77.7MB/s)      (1202MB/s)
READ:                (426MB/s)   (595MB/s)       (1181MB/s)
READ:                (422MB/s)   (572MB/s)       (1020MB/s)
READ:                (318MB/s)   (67.8MB/s)      (563MB/s)
WRITE:               (318MB/s)   (67.9MB/s)      (564MB/s)
READ:                (336MB/s)   (68.3MB/s)      (583MB/s)
WRITE:               (335MB/s)   (68.2MB/s)      (582MB/s)
WRITE:              (3441MB/s)   (152MB/s)       (2141MB/s)
WRITE:              (2507MB/s)   (147MB/s)       (1888MB/s)
READ:                (801MB/s)   (1146MB/s)      (1890MB/s)
READ:                (767MB/s)   (1096MB/s)      (2073MB/s)
READ:                (621MB/s)   (126MB/s)       (1009MB/s)
WRITE:               (621MB/s)   (126MB/s)       (1009MB/s)
READ:                (656MB/s)   (125MB/s)       (1075MB/s)
WRITE:               (657MB/s)   (126MB/s)       (1077MB/s)
WRITE:              (4772MB/s)   (225MB/s)       (3394MB/s)
WRITE:              (3905MB/s)   (211MB/s)       (2939MB/s)
READ:               (1216MB/s)   (1608MB/s)      (3218MB/s)
READ:               (1159MB/s)   (1431MB/s)      (2981MB/s)
READ:                (906MB/s)   (156MB/s)       (1457MB/s)
WRITE:               (907MB/s)   (156MB/s)       (1458MB/s)
READ:                (953MB/s)   (158MB/s)       (1595MB/s)
WRITE:               (952MB/s)   (157MB/s)       (1593MB/s)
WRITE:              (6036MB/s)   (265MB/s)       (4469MB/s)
WRITE:              (5059MB/s)   (263MB/s)       (3951MB/s)
READ:               (1618MB/s)   (2066MB/s)      (4276MB/s)
READ:               (1573MB/s)   (1942MB/s)      (3830MB/s)
READ:               (1202MB/s)   (227MB/s)       (1971MB/s)
WRITE:              (1200MB/s)   (227MB/s)       (1968MB/s)
READ:               (1265MB/s)   (226MB/s)       (2116MB/s)
WRITE:              (1264MB/s)   (226MB/s)       (2114MB/s)
WRITE:              (5339MB/s)   (233MB/s)       (3781MB/s)
WRITE:              (4298MB/s)   (234MB/s)       (3276MB/s)
READ:               (1626MB/s)   (2048MB/s)      (4081MB/s)
READ:               (1567MB/s)   (1929MB/s)      (3758MB/s)
READ:               (1174MB/s)   (205MB/s)       (1747MB/s)
WRITE:              (1173MB/s)   (204MB/s)       (1746MB/s)
READ:               (1214MB/s)   (208MB/s)       (1890MB/s)
WRITE:              (1215MB/s)   (208MB/s)       (1892MB/s)
WRITE:              (5666MB/s)   (270MB/s)       (4338MB/s)
WRITE:              (4828MB/s)   (267MB/s)       (3772MB/s)
READ:               (1803MB/s)   (2058MB/s)      (4946MB/s)
READ:               (1805MB/s)   (2156MB/s)      (4711MB/s)
READ:               (1334MB/s)   (235MB/s)       (2135MB/s)
WRITE:              (1335MB/s)   (235MB/s)       (2137MB/s)
READ:               (1364MB/s)   (236MB/s)       (2268MB/s)
WRITE:              (1365MB/s)   (237MB/s)       (2270MB/s)
WRITE:              (5474MB/s)   (270MB/s)       (4300MB/s)
WRITE:              (4666MB/s)   (266MB/s)       (3817MB/s)
READ:               (2022MB/s)   (2319MB/s)      (5472MB/s)
READ:               (1924MB/s)   (2260MB/s)      (5031MB/s)
READ:               (1369MB/s)   (242MB/s)       (2153MB/s)
WRITE:              (1370MB/s)   (242MB/s)       (2155MB/s)
READ:               (1499MB/s)   (246MB/s)       (2310MB/s)
WRITE:              (1497MB/s)   (246MB/s)       (2307MB/s)
WRITE:              (5558MB/s)   (273MB/s)       (4439MB/s)
WRITE:              (4763MB/s)   (271MB/s)       (3918MB/s)
READ:               (2201MB/s)   (2599MB/s)      (6062MB/s)
READ:               (2105MB/s)   (2463MB/s)      (5413MB/s)
READ:               (1490MB/s)   (252MB/s)       (2238MB/s)
WRITE:              (1488MB/s)   (252MB/s)       (2236MB/s)
READ:               (1566MB/s)   (254MB/s)       (2434MB/s)
WRITE:              (1568MB/s)   (254MB/s)       (2437MB/s)
WRITE:              (5120MB/s)   (264MB/s)       (4035MB/s)
WRITE:              (4531MB/s)   (267MB/s)       (3740MB/s)
READ:               (1940MB/s)   (2258MB/s)      (4986MB/s)
READ:               (2024MB/s)   (2387MB/s)      (4871MB/s)
READ:               (1343MB/s)   (246MB/s)       (2038MB/s)
WRITE:              (1342MB/s)   (246MB/s)       (2037MB/s)
READ:               (1553MB/s)   (238MB/s)       (2243MB/s)
WRITE:              (1552MB/s)   (238MB/s)       (2242MB/s)
WRITE:              (5345MB/s)   (271MB/s)       (3988MB/s)
WRITE:              (4750MB/s)   (254MB/s)       (3668MB/s)
READ:               (1876MB/s)   (2363MB/s)      (5150MB/s)
READ:               (1990MB/s)   (2256MB/s)      (5080MB/s)
READ:               (1355MB/s)   (250MB/s)       (2019MB/s)
WRITE:              (1356MB/s)   (251MB/s)       (2020MB/s)
READ:               (1490MB/s)   (252MB/s)       (2202MB/s)
WRITE:              (1488MB/s)   (252MB/s)       (2199MB/s)

jobs1                              perfstat
instructions                 52,065,555,710 (    0.79)    855,731,114,587 (    2.64)       54,280,709,944 (    1.40)
branches                     14,020,427,116 ( 725.847)    101,733,449,582 (1074.521)       11,170,591,067 ( 992.869)
branch-misses                    22,626,174 (   0.16%)        274,197,885 (   0.27%)           25,915,805 (   0.23%)
jobs2                              perfstat
instructions                103,633,110,402 (    0.75)  1,710,822,100,914 (    2.59)      107,879,874,104 (    1.28)
branches                     27,931,237,282 ( 679.203)    203,298,267,479 (1037.326)       22,185,350,842 ( 884.427)
branch-misses                    46,103,811 (   0.17%)        533,747,204 (   0.26%)           49,682,483 (   0.22%)
jobs3                              perfstat
instructions                154,857,283,657 (    0.76)  2,565,748,974,197 (    2.57)      161,515,435,813 (    1.31)
branches                     41,759,490,355 ( 670.529)    304,905,605,277 ( 978.765)       33,215,805,907 ( 888.003)
branch-misses                    74,263,293 (   0.18%)        759,746,240 (   0.25%)           76,841,196 (   0.23%)
jobs4                              perfstat
instructions                206,215,849,076 (    0.75)  3,420,169,460,897 (    2.60)      215,003,061,664 (    1.31)
branches                     55,632,141,739 ( 666.501)    406,394,977,433 ( 927.241)       44,214,322,251 ( 883.532)
branch-misses                   102,287,788 (   0.18%)      1,098,617,314 (   0.27%)          103,891,040 (   0.23%)
jobs5                              perfstat
instructions                258,711,315,588 (    0.67)  4,275,657,533,244 (    2.23)      269,332,235,685 (    1.08)
branches                     69,802,821,166 ( 588.823)    507,996,211,252 ( 797.036)       55,450,846,129 ( 735.095)
branch-misses                   129,217,214 (   0.19%)      1,243,284,991 (   0.24%)          173,512,278 (   0.31%)
jobs6                              perfstat
instructions                312,796,166,008 (    0.61)  5,133,896,344,660 (    2.02)      323,658,769,588 (    1.04)
branches                     84,372,488,583 ( 520.541)    610,310,494,402 ( 697.642)       66,683,292,992 ( 693.939)
branch-misses                   159,438,978 (   0.19%)      1,396,368,563 (   0.23%)          174,406,934 (   0.26%)
jobs7                              perfstat
instructions                363,211,372,930 (    0.56)  5,988,205,600,879 (    1.75)      377,824,674,156 (    0.93)
branches                     98,057,013,765 ( 463.117)    711,841,255,974 ( 598.762)       77,879,009,954 ( 600.443)
branch-misses                   199,513,153 (   0.20%)      1,507,651,077 (   0.21%)          248,203,369 (   0.32%)
jobs8                              perfstat
instructions                413,960,354,615 (    0.52)  6,842,918,558,378 (    1.45)      431,938,486,581 (    0.83)
branches                    111,812,574,884 ( 414.224)    813,299,084,518 ( 491.173)       89,062,699,827 ( 517.795)
branch-misses                   233,584,845 (   0.21%)      1,531,593,921 (   0.19%)          286,818,489 (   0.32%)
jobs9                              perfstat
instructions                465,976,220,300 (    0.53)  7,698,467,237,372 (    1.47)      486,352,600,321 (    0.84)
branches                    125,931,456,162 ( 424.063)    915,207,005,715 ( 498.192)      100,370,404,090 ( 517.439)
branch-misses                   256,992,445 (   0.20%)      1,782,809,816 (   0.19%)          345,239,380 (   0.34%)
jobs10                             perfstat
instructions                517,406,372,715 (    0.53)  8,553,527,312,900 (    1.48)      540,732,653,094 (    0.84)
branches                    139,839,780,676 ( 427.732)  1,016,737,699,389 ( 503.172)      111,696,557,638 ( 516.750)
branch-misses                   259,595,561 (   0.19%)      1,952,570,279 (   0.19%)          357,818,661 (   0.32%)

seconds elapsed        20.630411534     96.084546565    12.743373571
seconds elapsed        22.292627625     100.984155001   14.407413560
seconds elapsed        22.396016966     110.344880848   14.032201392
seconds elapsed        22.517330949     113.351459170   14.243074935
seconds elapsed        28.548305104     156.515193765   19.159286861
seconds elapsed        30.453538116     164.559937678   19.362492717
seconds elapsed        33.467108086     188.486827481   21.492612173
seconds elapsed        35.617727591     209.602677783   23.256422492
seconds elapsed        42.584239509     243.959902566   28.458540338
seconds elapsed        47.683632526     269.635248851   31.542404137

Over all, ZSTD has slower WRITE, but much faster READ (perhaps
a static compression buffer used during the test helped ZSTD a
lot), which results in faster test results.

Memory consumption (zram mm_stat file):

zram LZO mm_stat
mm_stat (jobs1): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs2): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs3): 2147483648 23068672 33558528        0 33562624        0        0
mm_stat (jobs4): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs5): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs6): 2147483648 23068672 33558528        0 33562624        0        0
mm_stat (jobs7): 2147483648 23068672 33558528        0 33566720        0        0
mm_stat (jobs8): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs9): 2147483648 23068672 33558528        0 33558528        0        0
mm_stat (jobs10): 2147483648 23068672 33558528        0 33562624        0        0

zram DEFLATE mm_stat
mm_stat (jobs1): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs2): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs3): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs4): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs5): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs6): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs7): 2147483648 16252928 25178112        0 25190400        0        0
mm_stat (jobs8): 2147483648 16252928 25178112        0 25190400        0        0
mm_stat (jobs9): 2147483648 16252928 25178112        0 25178112        0        0
mm_stat (jobs10): 2147483648 16252928 25178112        0 25178112        0        0

zram ZSTD mm_stat
mm_stat (jobs1): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs2): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs3): 2147483648 11010048 16781312        0 16785408        0        0
mm_stat (jobs4): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs5): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs6): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs7): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs8): 2147483648 11010048 16781312        0 16781312        0        0
mm_stat (jobs9): 2147483648 11010048 16781312        0 16785408        0        0
mm_stat (jobs10): 2147483648 11010048 16781312        0 16781312        0        0

==================================================================================

Official benchmarks [1]:

Compressor name         Ratio   Compression     Decompress.
zstd 1.1.3 -1           2.877   430 MB/s        1110 MB/s
zlib 1.2.8 -1           2.743   110 MB/s        400 MB/s
brotli 0.5.2 -0         2.708   400 MB/s        430 MB/s
quicklz 1.5.0 -1        2.238   550 MB/s        710 MB/s
lzo1x 2.09 -1           2.108   650 MB/s        830 MB/s
lz4 1.7.5               2.101   720 MB/s        3600 MB/s
snappy 1.1.3            2.091   500 MB/s        1650 MB/s
lzf 3.6 -1              2.077   400 MB/s        860 MB/s

Minchan said:

: I did test with my sample data and compared zstd with deflate.  zstd's
: compress ratio is lower a little bit but compression speed is much faster
: 3 times more and decompress speed is too 2 times more.  With different
: data, it is different but overall, zstd would be better for speed at the
: cost of a little lower compress ratio(about 5%) so I believe it's worth to
: replace deflate.

[1] https://github.com/facebook/zstd

Link: http://lkml.kernel.org/r/20170912050005.3247-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Tested-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 5ef3a8b12556d7fcba81edc74e9d85b029615ae0)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ieb6239dab92f560fa654d9cc29b1e266f2e44050

2 years agoUPSTREAM: lib: Add zstd modules
Nick Terrell [Thu, 10 Aug 2017 02:35:53 +0000 (19:35 -0700)]
UPSTREAM: lib: Add zstd modules

Add zstd compression and decompression kernel modules.
zstd offers a wide varity of compression speed and quality trade-offs.
It can compress at speeds approaching lz4, and quality approaching lzma.
zstd decompressions at speeds more than twice as fast as zlib, and
decompression speed remains roughly the same across all compression levels.

The code was ported from the upstream zstd source repository. The
`linux/zstd.h` header was modified to match linux kernel style.
The cross-platform and allocation code was stripped out. Instead zstd
requires the caller to pass a preallocated workspace. The source files
were clang-formatted [1] to match the Linux Kernel style as much as
possible. Otherwise, the code was unmodified. We would like to avoid
as much further manual modification to the source code as possible, so it
will be easier to keep the kernel zstd up to date.

I benchmarked zstd compression as a special character device. I ran zstd
and zlib compression at several levels, as well as performing no
compression, which measure the time spent copying the data to kernel space.
Data is passed to the compresser 4096 B at a time. The benchmark file is
located in the upstream zstd source repository under
`contrib/linux-kernel/zstd_compress_test.c` [2].

I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM.
The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor,
16 GB of RAM, and a SSD. I benchmarked using `silesia.tar` [3], which is
211,988,480 B large. Run the following commands for the benchmark:

    sudo modprobe zstd_compress_test
    sudo mknod zstd_compress_test c 245 0
    sudo cp silesia.tar zstd_compress_test

The time is reported by the time of the userland `cp`.
The MB/s is computed with

    1,536,217,008 B / time(buffer size, hash)

which includes the time to copy from userland.
The Adjusted MB/s is computed with

    1,536,217,088 B / (time(buffer size, hash) - time(buffer size, none)).

The memory reported is the amount of memory the compressor requests.

| Method   | Size (B) | Time (s) | Ratio | MB/s    | Adj MB/s | Mem (MB) |
|----------|----------|----------|-------|---------|----------|----------|
| none     | 11988480 |    0.100 |     1 | 2119.88 |        - |        - |
| zstd -1  | 73645762 |    1.044 | 2.878 |  203.05 |   224.56 |     1.23 |
| zstd -3  | 66988878 |    1.761 | 3.165 |  120.38 |   127.63 |     2.47 |
| zstd -5  | 65001259 |    2.563 | 3.261 |   82.71 |    86.07 |     2.86 |
| zstd -10 | 60165346 |   13.242 | 3.523 |   16.01 |    16.13 |    13.22 |
| zstd -15 | 58009756 |   47.601 | 3.654 |    4.45 |     4.46 |    21.61 |
| zstd -19 | 54014593 |  102.835 | 3.925 |    2.06 |     2.06 |    60.15 |
| zlib -1  | 77260026 |    2.895 | 2.744 |   73.23 |    75.85 |     0.27 |
| zlib -3  | 72972206 |    4.116 | 2.905 |   51.50 |    52.79 |     0.27 |
| zlib -6  | 68190360 |    9.633 | 3.109 |   22.01 |    22.24 |     0.27 |
| zlib -9  | 67613382 |   22.554 | 3.135 |    9.40 |     9.44 |     0.27 |

I benchmarked zstd decompression using the same method on the same machine.
The benchmark file is located in the upstream zstd repo under
`contrib/linux-kernel/zstd_decompress_test.c` [4]. The memory reported is
the amount of memory required to decompress data compressed with the given
compression level. If you know the maximum size of your input, you can
reduce the memory usage of decompression irrespective of the compression
level.

| Method   | Time (s) | MB/s    | Adjusted MB/s | Memory (MB) |
|----------|----------|---------|---------------|-------------|
| none     |    0.025 | 8479.54 |             - |           - |
| zstd -1  |    0.358 |  592.15 |        636.60 |        0.84 |
| zstd -3  |    0.396 |  535.32 |        571.40 |        1.46 |
| zstd -5  |    0.396 |  535.32 |        571.40 |        1.46 |
| zstd -10 |    0.374 |  566.81 |        607.42 |        2.51 |
| zstd -15 |    0.379 |  559.34 |        598.84 |        4.61 |
| zstd -19 |    0.412 |  514.54 |        547.77 |        8.80 |
| zlib -1  |    0.940 |  225.52 |        231.68 |        0.04 |
| zlib -3  |    0.883 |  240.08 |        247.07 |        0.04 |
| zlib -6  |    0.844 |  251.17 |        258.84 |        0.04 |
| zlib -9  |    0.837 |  253.27 |        287.64 |        0.04 |

Tested in userland using the test-suite in the zstd repo under
`contrib/linux-kernel/test/UserlandTest.cpp` [5] by mocking the kernel
functions. Fuzz tested using libfuzzer [6] with the fuzz harnesses under
`contrib/linux-kernel/test/{RoundTripCrash.c,DecompressCrash.c}` [7] [8]
with ASAN, UBSAN, and MSAN. Additionaly, it was tested while testing the
BtrFS and SquashFS patches coming next.

[1] https://clang.llvm.org/docs/ClangFormat.html
[2] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/zstd_compress_test.c
[3] http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia
[4] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/zstd_decompress_test.c
[5] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/test/UserlandTest.cpp
[6] http://llvm.org/docs/LibFuzzer.html
[7] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/test/RoundTripCrash.c
[8] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/test/DecompressCrash.c

zstd source repository: https://github.com/facebook/zstd

Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 73f3d1b48f5069d46ba48aa28c2898dc93185560)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I47b9d43a8065b2b5a1362f8458065f0811cf70b9

2 years agoUPSTREAM: lib: Add xxhash module
Nick Terrell [Fri, 4 Aug 2017 20:19:17 +0000 (13:19 -0700)]
UPSTREAM: lib: Add xxhash module

Adds xxhash kernel module with xxh32 and xxh64 hashes. xxhash is an
extremely fast non-cryptographic hash algorithm for checksumming.
The zstd compression and decompression modules added in the next patch
require xxhash. I extracted it out from zstd since it is useful on its
own. I copied the code from the upstream XXHash source repository and
translated it into kernel style. I ran benchmarks and tests in the kernel
and tests in userland.

I benchmarked xxhash as a special character device. I ran in four modes,
no-op, xxh32, xxh64, and crc32. The no-op mode simply copies the data to
kernel space and ignores it. The xxh32, xxh64, and crc32 modes compute
hashes on the copied data. I also ran it with four different buffer sizes.
The benchmark file is located in the upstream zstd source repository under
`contrib/linux-kernel/xxhash_test.c` [1].

I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM.
The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor,
16 GB of RAM, and a SSD. I benchmarked using the file `filesystem.squashfs`
from `ubuntu-16.10-desktop-amd64.iso`, which is 1,536,217,088 B large.
Run the following commands for the benchmark:

    modprobe xxhash_test
    mknod xxhash_test c 245 0
    time cp filesystem.squashfs xxhash_test

The time is reported by the time of the userland `cp`.
The GB/s is computed with

    1,536,217,008 B / time(buffer size, hash)

which includes the time to copy from userland.
The Normalized GB/s is computed with

    1,536,217,088 B / (time(buffer size, hash) - time(buffer size, none)).

| Buffer Size (B) | Hash  | Time (s) | GB/s | Adjusted GB/s |
|-----------------|-------|----------|------|---------------|
|            1024 | none  |    0.408 | 3.77 |             - |
|            1024 | xxh32 |    0.649 | 2.37 |          6.37 |
|            1024 | xxh64 |    0.542 | 2.83 |         11.46 |
|            1024 | crc32 |    1.290 | 1.19 |          1.74 |
|            4096 | none  |    0.380 | 4.04 |             - |
|            4096 | xxh32 |    0.645 | 2.38 |          5.79 |
|            4096 | xxh64 |    0.500 | 3.07 |         12.80 |
|            4096 | crc32 |    1.168 | 1.32 |          1.95 |
|            8192 | none  |    0.351 | 4.38 |             - |
|            8192 | xxh32 |    0.614 | 2.50 |          5.84 |
|            8192 | xxh64 |    0.464 | 3.31 |         13.60 |
|            8192 | crc32 |    1.163 | 1.32 |          1.89 |
|           16384 | none  |    0.346 | 4.43 |             - |
|           16384 | xxh32 |    0.590 | 2.60 |          6.30 |
|           16384 | xxh64 |    0.466 | 3.30 |         12.80 |
|           16384 | crc32 |    1.183 | 1.30 |          1.84 |

Tested in userland using the test-suite in the zstd repo under
`contrib/linux-kernel/test/XXHashUserlandTest.cpp` [2] by mocking the
kernel functions. A line in each branch of every function in `xxhash.c`
was commented out to ensure that the test-suite fails. Additionally
tested while testing zstd and with SMHasher [3].

[1] https://phabricator.intern.facebook.com/P57526246
[2] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/test/XXHashUserlandTest.cpp
[3] https://github.com/aappleby/smhasher

zstd source repository: https://github.com/facebook/zstd
XXHash source repository: https://github.com/cyan4973/xxhash

Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 5d2405227a9eaea48e8cc95756a06d407b11f141)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I4b63e96457f17cf455591e8f35058dacd7aa9004

2 years agoUPSTREAM: zram: rework copy of compressor name in comp_algorithm_store()
Matthias Kaehlcke [Thu, 10 Aug 2017 22:24:29 +0000 (15:24 -0700)]
UPSTREAM: zram: rework copy of compressor name in comp_algorithm_store()

comp_algorithm_store() passes the size of the source buffer to strlcpy()
instead of the destination buffer size.  Make it explicit that the two
buffers have the same size and use strcpy() instead of strlcpy().  The
latter can be done safely since the function ensures that the string in
the source buffer is terminated.

Link: http://lkml.kernel.org/r/20170803163350.45245-1-mka@chromium.org
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit f357e345eef7863da037e0243f2d3df4ba6df986)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ic9667b215ce5e0717bc6829d65e43e9b79602362

2 years agoUPSTREAM: zram: constify attribute_group structures.
Arvind Yadav [Mon, 10 Jul 2017 22:50:15 +0000 (15:50 -0700)]
UPSTREAM: zram: constify attribute_group structures.

attribute_groups are not supposed to change at runtime.  All functions
working with attribute_groups provided by <linux/sysfs.h> work with
const attribute_group.  So mark the non-const structs as const.

File size before:
   text    data     bss     dec     hex filename
   8293     841       4    9138    23b2 drivers/block/zram/zram_drv.o

File size After adding 'const':
   text    data     bss     dec     hex filename
   8357     777       4    9138    23b2 drivers/block/zram/zram_drv.o

Link: http://lkml.kernel.org/r/65680c1c4d85818f7094cbfa31c91bf28185ba1b.1499061182.git.arvind.yadav.cs@gmail.com
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit bc1bb362334ebc4c65dd4301f10fb70902b3db7d)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ic0765dea8c2fadb18623605ba48748a9b33df3fa

2 years agoUPSTREAM: zram: count same page write as page_stored
Minchan Kim [Thu, 6 Jul 2017 22:37:12 +0000 (15:37 -0700)]
UPSTREAM: zram: count same page write as page_stored

Regardless of whether it is same page or not, it's surely write and
stored to zram so we should increase pages_stored stat.  Otherwise, user
can see zero value via mm_stats although he writes a lot of pages to
zram.

Link: http://lkml.kernel.org/r/1494834068-27004-1-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 51f9f82c855d65ef14c2af10e0d2c86ec332a182)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I006d80df413a0fe0fd7dd58e535c6a2c03ab2c9d

2 years agoUPSTREAM: zram: reduce load operation in page_same_filled
Sangwoo Park [Wed, 3 May 2017 21:55:56 +0000 (14:55 -0700)]
UPSTREAM: zram: reduce load operation in page_same_filled

In page_same_filled function, all elements in the page is compared with
next index value.  The current comparison routine compares the (i)th and
(i+1)th values of the page.

In this case, two load operaions occur for each comparison.  But if we
store first value of the page stores at 'val' variable and using it to
compare with others, the load opearation is reduced.  It reduce load
operation per page by up to 64times.

Link: http://lkml.kernel.org/r/1488428104-7257-1-git-send-email-sangwoo2.park@lge.com
Signed-off-by: Sangwoo Park <sangwoo2.park@lge.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit f0fe9984656604ea8effd5ff82709ff8ce1f954b)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I6b58b583e83139eee9f0540da12850c43510cb8e

2 years agoUPSTREAM: zram: use zram_free_page instead of open-coded
Minchan Kim [Wed, 3 May 2017 21:55:53 +0000 (14:55 -0700)]
UPSTREAM: zram: use zram_free_page instead of open-coded

The zram_free_page already handles NULL handle case and same page so use
it to reduce error probability.  (Acutaully, I made a mistake when I
handled same page feature)

Link: http://lkml.kernel.org/r/1492052365-16169-7-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 302128dce142d780417aa548bfd7ef4dfb89fa80)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ie38c52dfb1959377936b7cd9158ad1b5a02219bd

2 years agoUPSTREAM: zram: introduce zram data accessor
Minchan Kim [Wed, 3 May 2017 21:55:50 +0000 (14:55 -0700)]
UPSTREAM: zram: introduce zram data accessor

With element, sometime I got confused handle and element access.  It
might be my bad but I think it's time to introduce accessor to prevent
future idiot like me.  This patch is just clean-up patch so it shouldn't
change any behavior.

Link: http://lkml.kernel.org/r/1492052365-16169-6-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 643ae61d0f41c48aa7179921fe15ba4b4d8ddfec)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I3916d5561ab9fb2917455cac74bee431fbe84b5d

2 years agoUPSTREAM: zram: remove zram_meta structure
Minchan Kim [Wed, 3 May 2017 21:55:47 +0000 (14:55 -0700)]
UPSTREAM: zram: remove zram_meta structure

It's redundant now.  Instead, remove it and use zram structure directly.

Link: http://lkml.kernel.org/r/1492052365-16169-5-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit beb6602cf87abee547b2692031185111f625153a)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I720a282710b97fd75c156305fd505d4497b89e4c

2 years agoUPSTREAM: zram: use zram_slot_lock instead of raw bit_spin_lock op
Minchan Kim [Wed, 3 May 2017 21:55:44 +0000 (14:55 -0700)]
UPSTREAM: zram: use zram_slot_lock instead of raw bit_spin_lock op

With this clean-up phase, I want to use zram's wrapper function to lock
table access which is more consistent with other zram's functions.

Link: http://lkml.kernel.org/r/1492052365-16169-4-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 86c49814d449ebc51c7d455ac8e3d17b9fa702eb)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I6afee89dce63dff6d759c78e25926814fc016107

2 years agoBACKPORT: zram: partial IO refactoring
Minchan Kim [Wed, 3 May 2017 21:55:41 +0000 (14:55 -0700)]
BACKPORT: zram: partial IO refactoring

For architecture(PAGE_SIZE > 4K), zram have supported partial IO.
However, the mixed code for handling normal/partial IO is too mess,
error-prone to modify IO handler functions with upcoming feature so this
patch aims for cleaning up zram's IO handling functions.

Link: http://lkml.kernel.org/r/1492052365-16169-3-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 1f7319c7427503abe2d365683588827b80f5714e)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I0f023d646d17f8156130cd0507b65f2223768adf

2 years agoBACKPORT: zram: handle multiple pages attached bio's bvec
Minchan Kim [Wed, 3 May 2017 21:55:38 +0000 (14:55 -0700)]
BACKPORT: zram: handle multiple pages attached bio's bvec

Patch series "zram clean up", v2.

This patchset aims to clean up zram .

[1] clean up multiple pages's bvec handling.
[2] clean up partial IO handling
[3-6] clean up zram via using accessor and removing pointless structure.

With [2-6] applied, we can get a few hundred bytes as well as huge
readibility enhance.

x86: 708 byte save

    add/remove: 1/1 grow/shrink: 0/11 up/down: 478/-1186 (-708)
    function                                     old     new   delta
    zram_special_page_read                         -     478    +478
    zram_reset_device                            317     314      -3
    mem_used_max_store                           131     128      -3
    compact_store                                 96      93      -3
    mm_stat_show                                 203     197      -6
    zram_add                                     719     712      -7
    zram_slot_free_notify                        229     214     -15
    zram_make_request                            819     803     -16
    zram_meta_free                               128     111     -17
    zram_free_page                               180     151     -29
    disksize_store                               432     361     -71
    zram_decompress_page.isra                    504       -    -504
    zram_bvec_rw                                2592    2080    -512
    Total: Before=25350773, After=25350065, chg -0.00%

ppc64: 231 byte save

    add/remove: 2/0 grow/shrink: 1/9 up/down: 681/-912 (-231)
    function                                     old     new   delta
    zram_special_page_read                         -     480    +480
    zram_slot_lock                                 -     200    +200
    vermagic                                      39      40      +1
    mm_stat_show                                 256     248      -8
    zram_meta_free                               200     184     -16
    zram_add                                     944     912     -32
    zram_free_page                               348     308     -40
    disksize_store                               572     492     -80
    zram_decompress_page                         664     564    -100
    zram_slot_free_notify                        292     160    -132
    zram_make_request                           1132    1000    -132
    zram_bvec_rw                                2768    2396    -372
    Total: Before=17565825, After=17565594, chg -0.00%

This patch (of 6):

Johannes Thumshirn reported system goes the panic when using NVMe over
Fabrics loopback target with zram.

The reason is zram expects each bvec in bio contains a single page
but nvme can attach a huge bulk of pages attached to the bio's bvec
so that zram's index arithmetic could be wrong so that out-of-bound
access makes system panic.

[1] in mainline solved solved the problem by limiting max_sectors with
SECTORS_PER_PAGE but it makes zram slow because bio should split with
each pages so this patch makes zram aware of multiple pages in a bvec
so it could solve without any regression(ie, bio split).

[1] 0bc315381fe9, zram: set physical queue limits to avoid array out of
    bounds accesses

Link: http://lkml.kernel.org/r/20170413134057.GA27499@bbox
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit e86942c7b6c1e1dd5e539f3bf3cfb63799163048)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ibedc9e8163fc16a0c2569e8c3e33dd81bb325ee5

2 years agoUPSTREAM: zram: fix operator precedence to get offset
Minchan Kim [Thu, 13 Apr 2017 21:56:35 +0000 (14:56 -0700)]
UPSTREAM: zram: fix operator precedence to get offset

In zram_rw_page, the logic to get offset is wrong by operator precedence
(i.e., "<<" is higher than "&").  With wrong offset, zram can corrupt
the user's data.  This patch fixes it.

Fixes: 8c7f01025 ("zram: implement rw_page operation of zram")
Link: http://lkml.kernel.org/r/1492042622-12074-1-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 4ca82dabc9fbf7bc5322aa54d802cb3cb7b125c5)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I6abb2aef381463976aea1fa8e7f5ca07367190e9

2 years agoBACKPORT: zram: extend zero pages to same element pages
zhouxianrong [Fri, 24 Feb 2017 22:59:27 +0000 (14:59 -0800)]
BACKPORT: zram: extend zero pages to same element pages

The idea is that without doing more calculations we extend zero pages to
same element pages for zram.  zero page is special case of same element
page with zero element.

1. the test is done under android 7.0
2. startup too many applications circularly
3. sample the zero pages, same pages (none-zero element)
   and total pages in function page_zero_filled

the result is listed as below:

ZERO SAME TOTAL
36214 17842 598196

ZERO/TOTAL  SAME/TOTAL   (ZERO+SAME)/TOTAL ZERO/SAME
AVERAGE 0.060631909  0.024990816  0.085622726 2.663825038
STDEV 0.00674612  0.005887625  0.009707034 2.115881328
MAX 0.069698422  0.030046087  0.094975336 7.56043956
MIN 0.03959586  0.007332205  0.056055193 1.928985507

from the above data, the benefit is about 2.5% and up to 3% of total
swapout pages.

The defect of the patch is that when we recovery a page from non-zero
element the operations are low efficient for partial read.

This patch extends zero_page to same_page so if there is any user to
have monitored zero_pages, he will be surprised if the number is
increased but it's not harmful, I believe.

[minchan@kernel.org: do not free same element pages in zram_meta_free]
Link: http://lkml.kernel.org/r/20170207065741.GA2567@bbox
Link: http://lkml.kernel.org/r/1483692145-75357-1-git-send-email-zhouxianrong@huawei.com
Link: http://lkml.kernel.org/r/1486307804-27903-1-git-send-email-minchan@kernel.org
Signed-off-by: zhouxianrong <zhouxianrong@huawei.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 8e19d540d107ee897eb9a874844060c94e2376c0)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I92ebb07a6ad96be82443d6e0c0d4f25cbe936915

2 years agoBACKPORT: zram: remove waitqueue for IO done
Minchan Kim [Fri, 24 Feb 2017 22:56:47 +0000 (14:56 -0800)]
BACKPORT: zram: remove waitqueue for IO done

zram_reset_device() waits for ongoing writepage pages to be completed by
zram->refcount logic.  However, it's pointless because before the reset,
we prevent further opening of zram by zram->claim and flush all of
pending IO by fsync_bdev so there should be no pending IO at the
zram_reset_device().

So let's remove that code which is even broken due to the lack of
wake_up elsewhere.

Link: http://lkml.kernel.org/r/1485145031-11661-1-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit a09759acaacf6cf738e1bc6c66d41485c87fd371)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I97170fb576be7baae63f82334af0dd5e91b16763

2 years agoUPSTREAM: zram: remove obsolete sysfs attrs
Sergey Senozhatsky [Wed, 22 Feb 2017 23:46:45 +0000 (15:46 -0800)]
UPSTREAM: zram: remove obsolete sysfs attrs

We had a deprecated_attr_warn() warning for 2 years and now the time has
come and we finally can do the cleanup.

The plan was as follows:

: per-stat sysfs attributes are considered to be deprecated.
: The basic strategy is:
: -- the existing RW nodes will be downgraded to WO nodes (in linux 4.11)
: -- deprecated RO sysfs nodes will eventually be removed (in linux 4.11)
:
: The list of deprecated attributes can be found here:
: Documentation/ABI/obsolete/sysfs-block-zram
:
: Basically, every attribute that has its own read accessible sysfs
: node (e.g. num_reads) *AND* is accessible via one of the stat files
: (zram<id>/stat or zram<id>/io_stat or zram<id>/mm_stat) is considered
: to be deprecated.

The patch also removes `obsolete/sysfs-block-zram', clean ups
`testing/sysfs-block-zram' and tweaks zram.txt files.

Link: http://lkml.kernel.org/r/20170118035838.11090-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit c87d1655c29500b459fb135258a93f8309ada9c7)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Idd86259230d6a4bf0feeee53b5b69f3f3df774d4

2 years agoUPSTREAM: zram: support BDI_CAP_STABLE_WRITES
Minchan Kim [Wed, 11 Jan 2017 00:58:21 +0000 (16:58 -0800)]
UPSTREAM: zram: support BDI_CAP_STABLE_WRITES

zram has used per-cpu stream feature from v4.7.  It aims for increasing
cache hit ratio of scratch buffer for compressing.  Downside of that
approach is that zram should ask memory space for compressed page in
per-cpu context which requires stricted gfp flag which could be failed.
If so, it retries to allocate memory space out of per-cpu context so it
could get memory this time and compress the data again, copies it to the
memory space.

In this scenario, zram assumes the data should never be changed but it is
not true without stable page support.  So, If the data is changed under
us, zram can make buffer overrun so that zsmalloc free object chain is
broken so system goes crash like below

   https://bugzilla.suse.com/show_bug.cgi?id=997574

This patch adds BDI_CAP_STABLE_WRITES to zram for declaring "I am block
device needing *stable write*".

Fixes: da9556a2367c ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/1482366980-3782-4-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hyeoncheol Lee <cheol.lee@lge.com>
Cc: <yjay.kim@lge.com>
Cc: Sangseok Lee <sangseok.lee@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit b09ab054b69b07077bd3292f67e777861ac796e5)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I3134a5882c1939792ffa71b8f31f7ab642a0e9a3

2 years agoUPSTREAM: zram: revalidate disk under init_lock
Minchan Kim [Wed, 11 Jan 2017 00:58:18 +0000 (16:58 -0800)]
UPSTREAM: zram: revalidate disk under init_lock

Commit b4c5c60920e3 ("zram: avoid lockdep splat by revalidate_disk")
moved revalidate_disk call out of init_lock to avoid lockdep
false-positive splat.  However, commit 08eee69fcf6b ("zram: remove
init_lock in zram_make_request") removed init_lock in IO path so there
is no worry about lockdep splat.  So, let's restore it.

This patch is needed to set BDI_CAP_STABLE_WRITES atomically in next
patch.

Fixes: da9556a2367c ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/1482366980-3782-3-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hyeoncheol Lee <cheol.lee@lge.com>
Cc: <yjay.kim@lge.com>
Cc: Sangseok Lee <sangseok.lee@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit e7ccfc4ccb703e0f033bd4617580039898e912dd)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Iebb6f694e46a797f8ce34029857c01c0c71086c7

2 years agoBACKPORT: mm: support anonymous stable page
Minchan Kim [Wed, 11 Jan 2017 00:58:15 +0000 (16:58 -0800)]
BACKPORT: mm: support anonymous stable page

During developemnt for zram-swap asynchronous writeback, I found strange
corruption of compressed page, resulting in:

  Modules linked in: zram(E)
  CPU: 3 PID: 1520 Comm: zramd-1 Tainted: G            E   4.8.0-mm1-00320-ge0d4894c9c38-dirty #3274
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
  task: ffff88007620b840 task.stack: ffff880078090000
  RIP: set_freeobj.part.43+0x1c/0x1f
  RSP: 0018:ffff880078093ca8  EFLAGS: 00010246
  RAX: 0000000000000018 RBX: ffff880076798d88 RCX: ffffffff81c408c8
  RDX: 0000000000000018 RSI: 0000000000000000 RDI: 0000000000000246
  RBP: ffff880078093cb0 R08: 0000000000000000 R09: 0000000000000000
  R10: ffff88005bc43030 R11: 0000000000001df3 R12: ffff880076798d88
  R13: 000000000005bc43 R14: ffff88007819d1b8 R15: 0000000000000001
  FS:  0000000000000000(0000) GS:ffff88007e380000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fc934048f20 CR3: 0000000077b01000 CR4: 00000000000406e0
  Call Trace:
    obj_malloc+0x22b/0x260
    zs_malloc+0x1e4/0x580
    zram_bvec_rw+0x4cd/0x830 [zram]
    page_requests_rw+0x9c/0x130 [zram]
    zram_thread+0xe6/0x173 [zram]
    kthread+0xca/0xe0
    ret_from_fork+0x25/0x30

With investigation, it reveals currently stable page doesn't support
anonymous page.  IOW, reuse_swap_page can reuse the page without waiting
writeback completion so it can overwrite page zram is compressing.

Unfortunately, zram has used per-cpu stream feature from v4.7.
It aims for increasing cache hit ratio of scratch buffer for
compressing. Downside of that approach is that zram should ask
memory space for compressed page in per-cpu context which requires
stricted gfp flag which could be failed. If so, it retries to
allocate memory space out of per-cpu context so it could get memory
this time and compress the data again, copies it to the memory space.

In this scenario, zram assumes the data should never be changed
but it is not true unless stable page supports. So, If the data is
changed under us, zram can make buffer overrun because second
compression size could be bigger than one we got in previous trial
and blindly, copy bigger size object to smaller buffer which is
buffer overrun. The overrun breaks zsmalloc free object chaining
so system goes crash like above.

I think below is same problem.
https://bugzilla.suse.com/show_bug.cgi?id=997574

Unfortunately, reuse_swap_page should be atomic so that we cannot wait on
writeback in there so the approach in this patch is simply return false if
we found it needs stable page.  Although it increases memory footprint
temporarily, it happens rarely and it should be reclaimed easily althoug
it happened.  Also, It would be better than waiting of IO completion,
which is critial path for application latency.

Fixes: da9556a2367c ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/20161120233015.GA14113@bbox
Link: http://lkml.kernel.org/r/1482366980-3782-2-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hyeoncheol Lee <cheol.lee@lge.com>
Cc: <yjay.kim@lge.com>
Cc: Sangseok Lee <sangseok.lee@lge.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit f05714293a591038304ddae7cb0dd747bb3786cc)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I0fa5012aff9daf614b2d1d04f35b86ff7043ff21

2 years agoUPSTREAM: zram: use __GFP_MOVABLE for memory allocation
Minchan Kim [Tue, 26 Jul 2016 22:23:34 +0000 (15:23 -0700)]
UPSTREAM: zram: use __GFP_MOVABLE for memory allocation

Zsmalloc is ready for page migration so zram can use __GFP_MOVABLE from
now on.

I did test to see how it helps to make higher order pages.  Test
scenario is as follows.

KVM guest, 1G memory, ext4 formated zram block device,

  for i in `seq 1 8`;
  do
          dd if=/dev/vda1 of=mnt/test$i.txt bs=128M count=1 &
  done

  wait `pidof dd`

  for i in `seq 1 2 8`;
  do
          rm -rf mnt/test$i.txt
  done
  fstrim -v mnt

  echo "init"
  cat /proc/buddyinfo

  echo "compaction"
  echo 1 > /proc/sys/vm/compact_memory
  cat /proc/buddyinfo

old:

  init
  Node 0, zone      DMA    208    120     51     41     11      0      0      0      0      0      0
  Node 0, zone    DMA32  16380  13777   9184   3805    789     54      3      0      0      0      0
  compaction
  Node 0, zone      DMA    132     82     40     39     16      2      1      0      0      0      0
  Node 0, zone    DMA32   5219   5526   4969   3455   1831    677    139     15      0      0      0

new:

  init
  Node 0, zone      DMA    379    115     97     19      2      0      0      0      0      0      0
  Node 0, zone    DMA32  18891  16774  10862   3947    637     21      0      0      0      0      0
  compaction
  Node 0, zone      DMA    214     66     87     29     10      3      0      0      0      0      0
  Node 0, zone    DMA32   1612   3139   3154   2469   1745    990    384     94      7      0      0

As you can see, compaction made so many high-order pages. Yay!

Link: http://lkml.kernel.org/r/1464736881-24886-13-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 9bc482d3460501ac809457af26b46b72cd7dc212)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I5d7f6eaa4c2d8d3f4da30fc2bd21f4db1be95e50

2 years agoUPSTREAM: zram: drop gfp_t from zcomp_strm_alloc()
Sergey Senozhatsky [Tue, 26 Jul 2016 22:22:59 +0000 (15:22 -0700)]
UPSTREAM: zram: drop gfp_t from zcomp_strm_alloc()

We now allocate streams from CPU_UP hot-plug path, there are no
context-dependent stream allocations anymore and we can schedule from
zcomp_strm_alloc().  Use GFP_KERNEL directly and drop a gfp_t parameter.

Link: http://lkml.kernel.org/r/20160531122017.2878-9-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 16d37725a042cc66f9ee95889dd40e734264508e)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: If09c4a97f3d3e45ad578d2b1d64b26f65617774d

2 years agoUPSTREAM: zram: add more compression algorithms
Sergey Senozhatsky [Tue, 26 Jul 2016 22:22:56 +0000 (15:22 -0700)]
UPSTREAM: zram: add more compression algorithms

Add "deflate", "lz4hc", "842" algorithms to the list of known
compression backends.  The real availability of those algorithms,
however, depends on the corresponding CONFIG_CRYPTO_FOO config options.

[sergey.senozhatsky@gmail.com: zram-add-more-compression-algorithms-v3]
Link: http://lkml.kernel.org/r/20160604024902.11778-7-sergey.senozhatsky@gmail.com
Link: http://lkml.kernel.org/r/20160531122017.2878-8-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit eb9f56d82547db407779967a2251ea28969245b0)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ie46c7676363ef13c559b45dab4968e2cc48a6cbe

2 years agoUPSTREAM: zram: delete custom lzo/lz4
Sergey Senozhatsky [Tue, 26 Jul 2016 22:22:54 +0000 (15:22 -0700)]
UPSTREAM: zram: delete custom lzo/lz4

Remove lzo/lz4 backends, we use crypto API now.

[sergey.senozhatsky@gmail.com: zram-delete-custom-lzo-lz4-v3]
Link: http://lkml.kernel.org/r/20160604024902.11778-6-sergey.senozhatsky@gmail.com
Link: http://lkml.kernel.org/r/20160531122017.2878-7-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit ce1ed9f98e888aa220fb09da2e2bcfcfba218a27)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ic2aa300a1a66b61740da73833dab252dc0d4b74a

2 years agoUPSTREAM: zram: cosmetic: cleanup documentation
Sergey Senozhatsky [Tue, 26 Jul 2016 22:22:51 +0000 (15:22 -0700)]
UPSTREAM: zram: cosmetic: cleanup documentation

zram documentation is a mix of different styles: spaces, tabs, tabs +
spaces, etc.  Clean it up.

Link: http://lkml.kernel.org/r/20160531122017.2878-6-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 69a30a8d2ac17c8080cf6ebfc91149fd6c2648b3)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ib71a1933e3da12b3a9f29b805a458cdc9815c36b

2 years agoUPSTREAM: zram: use crypto api to check alg availability
Sergey Senozhatsky [Tue, 26 Jul 2016 22:22:48 +0000 (15:22 -0700)]
UPSTREAM: zram: use crypto api to check alg availability

There is no way to get a string with all the crypto comp algorithms
supported by the crypto comp engine, so we need to maintain our own
backends list.  At the same time we additionally need to use
crypto_has_comp() to make sure that the user has requested a compression
algorithm that is recognized by the crypto comp engine.  Relying on
/proc/crypto is not an options here, because it does not show
not-yet-inserted compression modules.

Example:

 modprobe zram
 cat /proc/crypto | grep -i lz4
 modprobe lz4
 cat /proc/crypto | grep -i lz4
name         : lz4
driver       : lz4-generic
module       : lz4

So the user can't tell exactly if the lz4 is really supported from
/proc/crypto output, unless someone or something has loaded it.

This patch also adds crypto_has_comp() to zcomp_available_show().  We
store all the compression algorithms names in zcomp's `backends' array,
regardless the CONFIG_CRYPTO_FOO configuration, but show only those that
are also supported by crypto engine.  This helps user to know the exact
list of compression algorithms that can be used.

Example:
  module lz4 is not loaded yet, but is supported by the crypto
  engine. /proc/crypto has no information on this module, while
  zram's `comp_algorithm' lists it:

 cat /proc/crypto | grep -i lz4

 cat /sys/block/zram0/comp_algorithm
[lzo] lz4 deflate lz4hc 842

We still use the `backends' array to determine if the requested
compression backend is known to crypto api.  This array, however, may not
contain some entries, therefore as the last step we call crypto_has_comp()
function which attempts to insmod the requested compression algorithm to
determine if crypto api supports it.  The advantage of this method is that
now we permit the usage of out-of-tree crypto compression modules
(implementing S/W or H/W compression).

[sergey.senozhatsky@gmail.com: zram-use-crypto-api-to-check-alg-availability-v3]
Link: http://lkml.kernel.org/r/20160604024902.11778-4-sergey.senozhatsky@gmail.com
Link: http://lkml.kernel.org/r/20160531122017.2878-5-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 415403be37e204632b17bdb6857890fe5a220cea)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I7c823238329bd6e5180386507d16123228804cc5

2 years agoBACKPORT: zram: switch to crypto compress API
Sergey Senozhatsky [Tue, 26 Jul 2016 22:22:45 +0000 (15:22 -0700)]
BACKPORT: zram: switch to crypto compress API

We don't have an idle zstreams list anymore and our write path now works
absolutely differently, preventing preemption during compression.  This
removes possibilities of read paths preempting writes at wrong places
(which could badly affect the performance of both paths) and at the same
time opens the door for a move from custom LZO/LZ4 compression backends
implementation to a more generic one, using crypto compress API.

Joonsoo Kim [1] attempted to do this a while ago, but faced with the
need of introducing a new crypto API interface.  The root cause was the
fact that crypto API compression algorithms require a compression stream
structure (in zram terminology) for both compression and decompression
ops, while in reality only several of compression algorithms really need
it.  This resulted in a concept of context-less crypto API compression
backends [2].  Both write and read paths, though, would have been
executed with the preemption enabled, which in the worst case could have
resulted in a decreased worst-case performance, e.g.  consider the
following case:

CPU0

zram_write()
  spin_lock()
    take the last idle stream
  spin_unlock()

<< preempted >>

zram_read()
  spin_lock()
   no idle streams
  spin_unlock()
  schedule()

resuming zram_write compression()

but it took me some time to realize that, and it took even longer to
evolve zram and to make it ready for crypto API.  The key turned out to be
-- drop the idle streams list entirely.  Without the idle streams list we
are free to use compression algorithms that require compression stream for
decompression (read), because streams are now placed in per-cpu data and
each write path has to disable preemption for compression op, almost
completely eliminating the aforementioned case (technically, we still have
a small chance, because write path has a fast and a slow paths and the
slow path is executed with the preemption enabled; but the frequency of
failed fast path is too low).

TEST
====

- 4 CPUs, x86_64 system
- 3G zram, lzo
- fio tests: read, randread, write, randwrite, rw, randrw

test script [3] command:
 ZRAM_SIZE=3G LOG_SUFFIX=XXXX FIO_LOOPS=5 ./zram-fio-test.sh

                   BASE           PATCHED
jobs1
READ:           2527.2MB/s  2482.7MB/s
READ:           2102.7MB/s  2045.0MB/s
WRITE:          1284.3MB/s  1324.3MB/s
WRITE:          1080.7MB/s  1101.9MB/s
READ:           430125KB/s  437498KB/s
WRITE:          430538KB/s  437919KB/s
READ:           399593KB/s  403987KB/s
WRITE:          399910KB/s  404308KB/s
jobs2
READ:           8133.5MB/s  7854.8MB/s
READ:           7086.6MB/s  6912.8MB/s
WRITE:          3177.2MB/s  3298.3MB/s
WRITE:          2810.2MB/s  2871.4MB/s
READ:           1017.6MB/s  1023.4MB/s
WRITE:          1018.2MB/s  1023.1MB/s
READ:           977836KB/s  984205KB/s
WRITE:          979435KB/s  985814KB/s
jobs3
READ:           13557MB/s  13391MB/s
READ:           11876MB/s  11752MB/s
WRITE:          4641.5MB/s  4682.1MB/s
WRITE:          4164.9MB/s  4179.3MB/s
READ:           1453.8MB/s  1455.1MB/s
WRITE:          1455.1MB/s  1458.2MB/s
READ:           1387.7MB/s  1395.7MB/s
WRITE:          1386.1MB/s  1394.9MB/s
jobs4
READ:           20271MB/s  20078MB/s
READ:           18033MB/s  17928MB/s
WRITE:          6176.8MB/s  6180.5MB/s
WRITE:          5686.3MB/s  5705.3MB/s
READ:           2009.4MB/s  2006.7MB/s
WRITE:          2007.5MB/s  2004.9MB/s
READ:           1929.7MB/s  1935.6MB/s
WRITE:          1926.8MB/s  1932.6MB/s
jobs5
READ:           18823MB/s  19024MB/s
READ:           18968MB/s  19071MB/s
WRITE:          6191.6MB/s  6372.1MB/s
WRITE:          5818.7MB/s  5787.1MB/s
READ:           2011.7MB/s  1981.3MB/s
WRITE:          2011.4MB/s  1980.1MB/s
READ:           1949.3MB/s  1935.7MB/s
WRITE:          1940.4MB/s  1926.1MB/s
jobs6
READ:           21870MB/s  21715MB/s
READ:           19957MB/s  19879MB/s
WRITE:          6528.4MB/s  6537.6MB/s
WRITE:          6098.9MB/s  6073.6MB/s
READ:           2048.6MB/s  2049.9MB/s
WRITE:          2041.7MB/s  2042.9MB/s
READ:           2013.4MB/s  1990.4MB/s
WRITE:          2009.4MB/s  1986.5MB/s
jobs7
READ:           21359MB/s  21124MB/s
READ:           19746MB/s  19293MB/s
WRITE:          6660.4MB/s  6518.8MB/s
WRITE:          6211.6MB/s  6193.1MB/s
READ:           2089.7MB/s  2080.6MB/s
WRITE:          2085.8MB/s  2076.5MB/s
READ:           2041.2MB/s  2052.5MB/s
WRITE:          2037.5MB/s  2048.8MB/s
jobs8
READ:           20477MB/s  19974MB/s
READ:           18922MB/s  18576MB/s
WRITE:          6851.9MB/s  6788.3MB/s
WRITE:          6407.7MB/s  6347.5MB/s
READ:           2134.8MB/s  2136.1MB/s
WRITE:          2132.8MB/s  2134.4MB/s
READ:           2074.2MB/s  2069.6MB/s
WRITE:          2087.3MB/s  2082.4MB/s
jobs9
READ:           19797MB/s  19994MB/s
READ:           18806MB/s  18581MB/s
WRITE:          6878.7MB/s  6822.7MB/s
WRITE:          6456.8MB/s  6447.2MB/s
READ:           2141.1MB/s  2154.7MB/s
WRITE:          2144.4MB/s  2157.3MB/s
READ:           2084.1MB/s  2085.1MB/s
WRITE:          2091.5MB/s  2092.5MB/s
jobs10
READ:           19794MB/s  19784MB/s
READ:           18794MB/s  18745MB/s
WRITE:          6984.4MB/s  6676.3MB/s
WRITE:          6532.3MB/s  6342.7MB/s
READ:           2150.6MB/s  2155.4MB/s
WRITE:          2156.8MB/s  2161.5MB/s
READ:           2106.4MB/s  2095.6MB/s
WRITE:          2109.7MB/s  2098.4MB/s

                                    BASE                       PATCHED
jobs1                              perfstat
stalled-cycles-frontend     102,480,595,419 (  41.53%)   114,508,864,804 (  46.92%)
stalled-cycles-backend       51,941,417,832 (  21.05%)    46,836,112,388 (  19.19%)
instructions                283,612,054,215 (    1.15)   283,918,134,959 (    1.16)
branches                     56,372,560,385 ( 724.923)    56,449,814,753 ( 733.766)
branch-misses                   374,826,000 (   0.66%)       326,935,859 (   0.58%)
jobs2                              perfstat
stalled-cycles-frontend     155,142,745,777 (  40.99%)   164,170,979,198 (  43.82%)
stalled-cycles-backend       70,813,866,387 (  18.71%)    66,456,858,165 (  17.74%)
instructions                463,436,648,173 (    1.22)   464,221,890,191 (    1.24)
branches                     91,088,733,902 ( 760.088)    91,278,144,546 ( 769.133)
branch-misses                   504,460,363 (   0.55%)       394,033,842 (   0.43%)
jobs3                              perfstat
stalled-cycles-frontend     201,300,397,212 (  39.84%)   223,969,902,257 (  44.44%)
stalled-cycles-backend       87,712,593,974 (  17.36%)    81,618,888,712 (  16.19%)
instructions                642,869,545,023 (    1.27)   644,677,354,132 (    1.28)
branches                    125,724,560,594 ( 690.682)   126,133,159,521 ( 694.542)
branch-misses                   527,941,798 (   0.42%)       444,782,220 (   0.35%)
jobs4                              perfstat
stalled-cycles-frontend     246,701,197,429 (  38.12%)   280,076,030,886 (  43.29%)
stalled-cycles-backend      119,050,341,112 (  18.40%)   110,955,641,671 (  17.15%)
instructions                822,716,962,127 (    1.27)   825,536,969,320 (    1.28)
branches                    160,590,028,545 ( 688.614)   161,152,996,915 ( 691.068)
branch-misses                   650,295,287 (   0.40%)       550,229,113 (   0.34%)
jobs5                              perfstat
stalled-cycles-frontend     298,958,462,516 (  38.30%)   344,852,200,358 (  44.16%)
stalled-cycles-backend      137,558,742,122 (  17.62%)   129,465,067,102 (  16.58%)
instructions              1,005,714,688,752 (    1.29) 1,007,657,999,432 (    1.29)
branches                    195,988,773,962 ( 697.730)   196,446,873,984 ( 700.319)
branch-misses                   695,818,940 (   0.36%)       624,823,263 (   0.32%)
jobs6                              perfstat
stalled-cycles-frontend     334,497,602,856 (  36.71%)   387,590,419,779 (  42.38%)
stalled-cycles-backend      163,539,365,335 (  17.95%)   152,640,193,639 (  16.69%)
instructions              1,184,738,177,851 (    1.30) 1,187,396,281,677 (    1.30)
branches                    230,592,915,640 ( 702.902)   231,253,802,882 ( 702.356)
branch-misses                   747,934,786 (   0.32%)       643,902,424 (   0.28%)
jobs7                              perfstat
stalled-cycles-frontend     396,724,684,187 (  37.71%)   460,705,858,952 (  43.84%)
stalled-cycles-backend      188,096,616,496 (  17.88%)   175,785,787,036 (  16.73%)
instructions              1,364,041,136,608 (    1.30) 1,366,689,075,112 (    1.30)
branches                    265,253,096,936 ( 700.078)   265,890,524,883 ( 702.839)
branch-misses                   784,991,589 (   0.30%)       729,196,689 (   0.27%)
jobs8                              perfstat
stalled-cycles-frontend     440,248,299,870 (  36.92%)   509,554,793,816 (  42.46%)
stalled-cycles-backend      222,575,930,616 (  18.67%)   213,401,248,432 (  17.78%)
instructions              1,542,262,045,114 (    1.29) 1,545,233,932,257 (    1.29)
branches                    299,775,178,439 ( 697.666)   300,528,458,505 ( 694.769)
branch-misses                   847,496,084 (   0.28%)       748,794,308 (   0.25%)
jobs9                              perfstat
stalled-cycles-frontend     506,269,882,480 (  37.86%)   592,798,032,820 (  44.43%)
stalled-cycles-backend      253,192,498,861 (  18.93%)   233,727,666,185 (  17.52%)
instructions              1,721,985,080,913 (    1.29) 1,724,666,236,005 (    1.29)
branches                    334,517,360,255 ( 694.134)   335,199,758,164 ( 697.131)
branch-misses                   873,496,730 (   0.26%)       815,379,236 (   0.24%)
jobs10                             perfstat
stalled-cycles-frontend     549,063,363,749 (  37.18%)   651,302,376,662 (  43.61%)
stalled-cycles-backend      281,680,986,810 (  19.07%)   277,005,235,582 (  18.55%)
instructions              1,901,859,271,180 (    1.29) 1,906,311,064,230 (    1.28)
branches                    369,398,536,153 ( 694.004)   370,527,696,358 ( 688.409)
branch-misses                   967,929,335 (   0.26%)       890,125,056 (   0.24%)

                            BASE           PATCHED
seconds elapsed        79.421641008 78.735285546
seconds elapsed        61.471246133 60.869085949
seconds elapsed        62.317058173 62.224188495
seconds elapsed        60.030739363 60.081102518
seconds elapsed        74.070398362 74.317582865
seconds elapsed        84.985953007 85.414364176
seconds elapsed        97.724553255 98.173311344
seconds elapsed        109.488066758 110.268399318
seconds elapsed        122.768189405 122.967164498
seconds elapsed        135.130035105 136.934770801

On my other system (8 x86_64 CPUs, short version of test results):

                            BASE           PATCHED
seconds elapsed        19.518065994 19.806320662
seconds elapsed        15.172772749 15.594718291
seconds elapsed        13.820925970 13.821708564
seconds elapsed        13.293097816 14.585206405
seconds elapsed        16.207284118 16.064431606
seconds elapsed        17.958376158 17.771825767
seconds elapsed        19.478009164 19.602961508
seconds elapsed        21.347152811 21.352318709
seconds elapsed        24.478121126 24.171088735
seconds elapsed        26.865057442 26.767327618

So performance-wise the numbers are quite similar.

Also update zcomp interface to be more aligned with the crypto API.

[1] http://marc.info/?l=linux-kernel&m=144480832108927&w=2
[2] http://marc.info/?l=linux-kernel&m=145379613507518&w=2
[3] https://github.com/sergey-senozhatsky/zram-perf-test

Link: http://lkml.kernel.org/r/20160531122017.2878-3-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>
Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit ebaf9ab56d9d5f350969bd1ea8f47234623c9684)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ia0c362b7419de59e6c6ea81c37f99ef1d22c2b4b

2 years agoUPSTREAM: zram: rename zstrm find-release functions
Sergey Senozhatsky [Tue, 26 Jul 2016 22:22:42 +0000 (15:22 -0700)]
UPSTREAM: zram: rename zstrm find-release functions

This has started as a 'add zlib support' work, but after some thinking I
saw no blockers for a bigger change -- a switch to crypto API.

We don't have an idle zstreams list anymore and our write path now works
absolutely differently, preventing preemption during compression.  This
removes possibilities of read paths preempting writes at wrong places
and opens the door for a move from custom LZO/LZ4 compression backends
implementation to a more generic one, using crypto compress API.

This patch set also eliminates the need of a new context-less crypto API
interface, which was quite hard to sell, so we can move along faster.

benchmarks:

(x86_64, 4GB, zram-perf script)

perf reported run-time fio (max jobs=3).  I performed fio test with the
increasing number of parallel jobs (max to 3) on a 3G zram device, using
`static' data and the following crypto comp algorithms:

842, deflate, lz4, lz4hc, lzo

the output was:

 - test running time (which can tell us what algorithms performs faster)

and

 - zram mm_stat (which tells the compressed memory size, max used memory, etc).

It's just for information.  for example, LZ4HC has twice the running
time of LZO, but the compressed memory size is: 23592960 vs 34603008
bytes.

  test-fio-zram-842
     197.907655282 seconds time elapsed
     201.623142884 seconds time elapsed
     226.854291345 seconds time elapsed
  test-fio-zram-DEFLATE
     253.259516155 seconds time elapsed
     258.148563401 seconds time elapsed
     290.251909365 seconds time elapsed
  test-fio-zram-LZ4
      27.022598717 seconds time elapsed
      29.580522717 seconds time elapsed
      33.293463430 seconds time elapsed
  test-fio-zram-LZ4HC
      56.393954615 seconds time elapsed
      74.904659747 seconds time elapsed
     101.940998564 seconds time elapsed
  test-fio-zram-LZO
      28.155948075 seconds time elapsed
      30.390036330 seconds time elapsed
      34.455773159 seconds time elapsed

zram mm_stat-s (max fio jobs=3)

  test-fio-zram-842
  mm_stat (jobs1): 3221225472 673185792 690266112        0 690266112        0        0
  mm_stat (jobs2): 3221225472 673185792 690266112        0 690266112        0        0
  mm_stat (jobs3): 3221225472 673185792 690266112        0 690266112        0        0
  test-fio-zram-DEFLATE
  mm_stat (jobs1): 3221225472  24379392  37761024        0  37761024        0        0
  mm_stat (jobs2): 3221225472  24379392  37761024        0  37761024        0        0
  mm_stat (jobs3): 3221225472  24379392  37761024        0  37761024        0        0
  test-fio-zram-LZ4
  mm_stat (jobs1): 3221225472  23592960  37761024        0  37761024        0        0
  mm_stat (jobs2): 3221225472  23592960  37761024        0  37761024        0        0
  mm_stat (jobs3): 3221225472  23592960  37761024        0  37761024        0        0
  test-fio-zram-LZ4HC
  mm_stat (jobs1): 3221225472  23592960  37761024        0  37761024        0        0
  mm_stat (jobs2): 3221225472  23592960  37761024        0  37761024        0        0
  mm_stat (jobs3): 3221225472  23592960  37761024        0  37761024        0        0
  test-fio-zram-LZO
  mm_stat (jobs1): 3221225472  34603008  50335744        0  50335744        0        0
  mm_stat (jobs2): 3221225472  34603008  50335744        0  50335744        0        0
  mm_stat (jobs3): 3221225472  34603008  50335744        0  50339840        0        0

This patch (of 8):

We don't perform any zstream idle list lookup anymore, so
zcomp_strm_find()/zcomp_strm_release() names are not representative.

Rename to zcomp_stream_get()/zcomp_stream_put().

Link: http://lkml.kernel.org/r/20160531122017.2878-2-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 2aea8493d326bdf15446768333e1d2c91b040b5c)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I2f4c9e215bca73ba5adb1354aaec6e32e420920d

2 years agoUPSTREAM: zram: introduce per-device debug_stat sysfs node
Sergey Senozhatsky [Sat, 21 May 2016 00:00:02 +0000 (17:00 -0700)]
UPSTREAM: zram: introduce per-device debug_stat sysfs node

debug_stat sysfs is read-only and represents various debugging data that
zram developers may need.  This file is not meant to be used by anyone
else: its content is not documented and will change any time w/o any
notice.  Therefore, the output of debug_stat file contains a version
string.  To avoid any confusion, we will increase the version number
every time we modify the output.

At the moment this file exports only one value -- the number of
re-compressions, IOW, the number of times compression fast path has
failed.  This stat is temporary any will be useful in case if any
per-cpu compression streams regressions will be reported.

Link: http://lkml.kernel.org/r/20160513230834.GB26763@bbox
Link: http://lkml.kernel.org/r/20160511134553.12655-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 623e47fc64f8de480b322b7ed68855f97137e2a5)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: Ie0ef61db7aa0b2c713de1d8bf48e8a545b4276e9

2 years agoUPSTREAM: zram: remove max_comp_streams internals
Sergey Senozhatsky [Fri, 20 May 2016 23:59:59 +0000 (16:59 -0700)]
UPSTREAM: zram: remove max_comp_streams internals

Remove the internal part of max_comp_streams interface, since we
switched to per-cpu streams.  We will keep RW max_comp_streams attr
around, because:

a) we may (silently) switch back to idle compression streams list and
   don't want to disturb user space

b) max_comp_streams attr must wait for the next 'lay off cycle'; we
   give user space 2 years to adjust before we remove/downgrade the attr,
   and there are already several attrs scheduled for removal in 4.11, so
   it's too late for max_comp_streams.

This slightly change a user visible behaviour:

- First, reading from max_comp_stream file now will always return the
  number of online CPUs.

- Second, writing to max_comp_stream will not take any effect.

Link: http://lkml.kernel.org/r/20160503165546.25201-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 43209ea2d17aae1540d4e28274e36404f72702f2)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I1902e741b4d3b83c5bd0d66bf1bae021dbfe2056

2 years agoUPSTREAM: zram: user per-cpu compression streams
Sergey Senozhatsky [Fri, 20 May 2016 23:59:51 +0000 (16:59 -0700)]
UPSTREAM: zram: user per-cpu compression streams

Remove idle streams list and keep compression streams in per-cpu data.
This removes two contented spin_lock()/spin_unlock() calls from write
path and also prevent write OP from being preempted while holding the
compression stream, which can cause slow downs.

For instance, let's assume that we have N cpus and N-2
max_comp_streams.TASK1 owns the last idle stream, TASK2-TASK3 come in
with the write requests:

  TASK1            TASK2              TASK3
 zram_bvec_write()
  spin_lock
  find stream
  spin_unlock

  compress

  <<preempted>>   zram_bvec_write()
                   spin_lock
                   find stream
                   spin_unlock
                     no_stream
                       schedule
                                     zram_bvec_write()
                                      spin_lock
                                      find_stream
                                      spin_unlock
                                        no_stream
                                          schedule
   spin_lock
   release stream
   spin_unlock
     wake up TASK2

not only TASK2 and TASK3 will not get the stream, TASK1 will be
preempted in the middle of its operation; while we would prefer it to
finish compression and release the stream.

Test environment: x86_64, 4 CPU box, 3G zram, lzo

The following fio tests were executed:
      read, randread, write, randwrite, rw, randrw
with the increasing number of jobs from 1 to 10.

                  4 streams        8 streams       per-cpu
  ===========================================================
  jobs1
  READ:           2520.1MB/s       2566.5MB/s      2491.5MB/s
  READ:           2102.7MB/s       2104.2MB/s      2091.3MB/s
  WRITE:          1355.1MB/s       1320.2MB/s      1378.9MB/s
  WRITE:          1103.5MB/s       1097.2MB/s      1122.5MB/s
  READ:           434013KB/s       435153KB/s      439961KB/s
  WRITE:          433969KB/s       435109KB/s      439917KB/s
  READ:           403166KB/s       405139KB/s      403373KB/s
  WRITE:          403223KB/s       405197KB/s      403430KB/s
  jobs2
  READ:           7958.6MB/s       8105.6MB/s      8073.7MB/s
  READ:           6864.9MB/s       6989.8MB/s      7021.8MB/s
  WRITE:          2438.1MB/s       2346.9MB/s      3400.2MB/s
  WRITE:          1994.2MB/s       1990.3MB/s      2941.2MB/s
  READ:           981504KB/s       973906KB/s      1018.8MB/s
  WRITE:          981659KB/s       974060KB/s      1018.1MB/s
  READ:           937021KB/s       938976KB/s      987250KB/s
  WRITE:          934878KB/s       936830KB/s      984993KB/s
  jobs3
  READ:           13280MB/s        13553MB/s       13553MB/s
  READ:           11534MB/s        11785MB/s       11755MB/s
  WRITE:          3456.9MB/s       3469.9MB/s      4810.3MB/s
  WRITE:          3029.6MB/s       3031.6MB/s      4264.8MB/s
  READ:           1363.8MB/s       1362.6MB/s      1448.9MB/s
  WRITE:          1361.9MB/s       1360.7MB/s      1446.9MB/s
  READ:           1309.4MB/s       1310.6MB/s      1397.5MB/s
  WRITE:          1307.4MB/s       1308.5MB/s      1395.3MB/s
  jobs4
  READ:           20244MB/s        20177MB/s       20344MB/s
  READ:           17886MB/s        17913MB/s       17835MB/s
  WRITE:          4071.6MB/s       4046.1MB/s      6370.2MB/s
  WRITE:          3608.9MB/s       3576.3MB/s      5785.4MB/s
  READ:           1824.3MB/s       1821.6MB/s      1997.5MB/s
  WRITE:          1819.8MB/s       1817.4MB/s      1992.5MB/s
  READ:           1765.7MB/s       1768.3MB/s      1937.3MB/s
  WRITE:          1767.5MB/s       1769.1MB/s      1939.2MB/s
  jobs5
  READ:           18663MB/s        18986MB/s       18823MB/s
  READ:           16659MB/s        16605MB/s       16954MB/s
  WRITE:          3912.4MB/s       3888.7MB/s      6126.9MB/s
  WRITE:          3506.4MB/s       3442.5MB/s      5519.3MB/s
  READ:           1798.2MB/s       1746.5MB/s      1935.8MB/s
  WRITE:          1792.7MB/s       1740.7MB/s      1929.1MB/s
  READ:           1727.6MB/s       1658.2MB/s      1917.3MB/s
  WRITE:          1726.5MB/s       1657.2MB/s      1916.6MB/s
  jobs6
  READ:           21017MB/s        20922MB/s       21162MB/s
  READ:           19022MB/s        19140MB/s       18770MB/s
  WRITE:          3968.2MB/s       4037.7MB/s      6620.8MB/s
  WRITE:          3643.5MB/s       3590.2MB/s      6027.5MB/s
  READ:           1871.8MB/s       1880.5MB/s      2049.9MB/s
  WRITE:          1867.8MB/s       1877.2MB/s      2046.2MB/s
  READ:           1755.8MB/s       1710.3MB/s      1964.7MB/s
  WRITE:          1750.5MB/s       1705.9MB/s      1958.8MB/s
  jobs7
  READ:           21103MB/s        20677MB/s       21482MB/s
  READ:           18522MB/s        18379MB/s       19443MB/s
  WRITE:          4022.5MB/s       4067.4MB/s      6755.9MB/s
  WRITE:          3691.7MB/s       3695.5MB/s      5925.6MB/s
  READ:           1841.5MB/s       1933.9MB/s      2090.5MB/s
  WRITE:          1842.7MB/s       1935.3MB/s      2091.9MB/s
  READ:           1832.4MB/s       1856.4MB/s      1971.5MB/s
  WRITE:          1822.3MB/s       1846.2MB/s      1960.6MB/s
  jobs8
  READ:           20463MB/s        20194MB/s       20862MB/s
  READ:           18178MB/s        17978MB/s       18299MB/s
  WRITE:          4085.9MB/s       4060.2MB/s      7023.8MB/s
  WRITE:          3776.3MB/s       3737.9MB/s      6278.2MB/s
  READ:           1957.6MB/s       1944.4MB/s      2109.5MB/s
  WRITE:          1959.2MB/s       1946.2MB/s      2111.4MB/s
  READ:           1900.6MB/s       1885.7MB/s      2082.1MB/s
  WRITE:          1896.2MB/s       1881.4MB/s      2078.3MB/s
  jobs9
  READ:           19692MB/s        19734MB/s       19334MB/s
  READ:           17678MB/s        18249MB/s       17666MB/s
  WRITE:          4004.7MB/s       4064.8MB/s      6990.7MB/s
  WRITE:          3724.7MB/s       3772.1MB/s      6193.6MB/s
  READ:           1953.7MB/s       1967.3MB/s      2105.6MB/s
  WRITE:          1953.4MB/s       1966.7MB/s      2104.1MB/s
  READ:           1860.4MB/s       1897.4MB/s      2068.5MB/s
  WRITE:          1858.9MB/s       1895.9MB/s      2066.8MB/s
  jobs10
  READ:           19730MB/s        19579MB/s       19492MB/s
  READ:           18028MB/s        18018MB/s       18221MB/s
  WRITE:          4027.3MB/s       4090.6MB/s      7020.1MB/s
  WRITE:          3810.5MB/s       3846.8MB/s      6426.8MB/s
  READ:           1956.1MB/s       1994.6MB/s      2145.2MB/s
  WRITE:          1955.9MB/s       1993.5MB/s      2144.8MB/s
  READ:           1852.8MB/s       1911.6MB/s      2075.8MB/s
  WRITE:          1855.7MB/s       1914.6MB/s      2078.1MB/s

perf stat

                                  4 streams                       8 streams                       per-cpu
  ====================================================================================================================
  jobs1
  stalled-cycles-frontend      23,174,811,209 (  38.21%)     23,220,254,188 (  38.25%)       23,061,406,918 (  38.34%)
  stalled-cycles-backend       11,514,174,638 (  18.98%)     11,696,722,657 (  19.27%)       11,370,852,810 (  18.90%)
  instructions                 73,925,005,782 (    1.22)     73,903,177,632 (    1.22)       73,507,201,037 (    1.22)
  branches                     14,455,124,835 ( 756.063)     14,455,184,779 ( 755.281)       14,378,599,509 ( 758.546)
  branch-misses                    69,801,336 (   0.48%)         80,225,529 (   0.55%)           72,044,726 (   0.50%)
  jobs2
  stalled-cycles-frontend      49,912,741,782 (  46.11%)     50,101,189,290 (  45.95%)       32,874,195,633 (  35.11%)
  stalled-cycles-backend       27,080,366,230 (  25.02%)     27,949,970,232 (  25.63%)       16,461,222,706 (  17.58%)
  instructions                122,831,629,690 (    1.13)    122,919,846,419 (    1.13)      121,924,786,775 (    1.30)
  branches                     23,725,889,239 ( 692.663)     23,733,547,140 ( 688.062)       23,553,950,311 ( 794.794)
  branch-misses                    90,733,041 (   0.38%)         96,320,895 (   0.41%)           84,561,092 (   0.36%)
  jobs3
  stalled-cycles-frontend      66,437,834,608 (  45.58%)     63,534,923,344 (  43.69%)       42,101,478,505 (  33.19%)
  stalled-cycles-backend       34,940,799,661 (  23.97%)     34,774,043,148 (  23.91%)       21,163,324,388 (  16.68%)
  instructions                171,692,121,862 (    1.18)    171,775,373,044 (    1.18)      170,353,542,261 (    1.34)
  branches                     32,968,962,622 ( 628.723)     32,987,739,894 ( 630.512)       32,729,463,918 ( 717.027)
  branch-misses                   111,522,732 (   0.34%)        110,472,894 (   0.33%)           99,791,291 (   0.30%)
  jobs4
  stalled-cycles-frontend      98,741,701,675 (  49.72%)     94,797,349,965 (  47.59%)       54,535,655,381 (  33.53%)
  stalled-cycles-backend       54,642,609,615 (  27.51%)     55,233,554,408 (  27.73%)       27,882,323,541 (  17.14%)
  instructions                220,884,807,851 (    1.11)    220,930,887,273 (    1.11)      218,926,845,851 (    1.35)
  branches                     42,354,518,180 ( 592.105)     42,362,770,587 ( 590.452)       41,955,552,870 ( 716.154)
  branch-misses                   138,093,449 (   0.33%)        131,295,286 (   0.31%)          121,794,771 (   0.29%)
  jobs5
  stalled-cycles-frontend     116,219,747,212 (  48.14%)    110,310,397,012 (  46.29%)       66,373,082,723 (  33.70%)
  stalled-cycles-backend       66,325,434,776 (  27.48%)     64,157,087,914 (  26.92%)       32,999,097,299 (  16.76%)
  instructions                270,615,008,466 (    1.12)    270,546,409,525 (    1.14)      268,439,910,948 (    1.36)
  branches                     51,834,046,557 ( 599.108)     51,811,867,722 ( 608.883)       51,412,576,077 ( 729.213)
  branch-misses                   158,197,086 (   0.31%)        142,639,805 (   0.28%)          133,425,455 (   0.26%)
  jobs6
  stalled-cycles-frontend     138,009,414,492 (  48.23%)    139,063,571,254 (  48.80%)       75,278,568,278 (  32.80%)
  stalled-cycles-backend       79,211,949,650 (  27.68%)     79,077,241,028 (  27.75%)       37,735,797,899 (  16.44%)
  instructions                319,763,993,731 (    1.12)    319,937,782,834 (    1.12)      316,663,600,784 (    1.38)
  branches                     61,219,433,294 ( 595.056)     61,250,355,540 ( 598.215)       60,523,446,617 ( 733.706)
  branch-misses                   169,257,123 (   0.28%)        154,898,028 (   0.25%)          141,180,587 (   0.23%)
  jobs7
  stalled-cycles-frontend     162,974,812,119 (  49.20%)    159,290,061,987 (  48.43%)       88,046,641,169 (  33.21%)
  stalled-cycles-backend       92,223,151,661 (  27.84%)     91,667,904,406 (  27.87%)       44,068,454,971 (  16.62%)
  instructions                369,516,432,430 (    1.12)    369,361,799,063 (    1.12)      365,290,380,661 (    1.38)
  branches                     70,795,673,950 ( 594.220)     70,743,136,124 ( 597.876)       69,803,996,038 ( 732.822)
  branch-misses                   181,708,327 (   0.26%)        165,767,821 (   0.23%)          150,109,797 (   0.22%)
  jobs8
  stalled-cycles-frontend     185,000,017,027 (  49.30%)    182,334,345,473 (  48.37%)       99,980,147,041 (  33.26%)
  stalled-cycles-backend      105,753,516,186 (  28.18%)    107,937,830,322 (  28.63%)       51,404,177,181 (  17.10%)
  instructions                418,153,161,055 (    1.11)    418,308,565,828 (    1.11)      413,653,475,581 (    1.38)
  branches                     80,035,882,398 ( 592.296)     80,063,204,510 ( 589.843)       79,024,105,589 ( 730.530)
  branch-misses                   199,764,528 (   0.25%)        177,936,926 (   0.22%)          160,525,449 (   0.20%)
  jobs9
  stalled-cycles-frontend     210,941,799,094 (  49.63%)    204,714,679,254 (  48.55%)      114,251,113,756 (  33.96%)
  stalled-cycles-backend      122,640,849,067 (  28.85%)    122,188,553,256 (  28.98%)       58,360,041,127 (  17.35%)
  instructions                468,151,025,415 (    1.10)    467,354,869,323 (    1.11)      462,665,165,216 (    1.38)
  branches                     89,657,067,510 ( 585.628)     89,411,550,407 ( 588.990)       88,360,523,943 ( 730.151)
  branch-misses                   218,292,301 (   0.24%)        191,701,247 (   0.21%)          178,535,678 (   0.20%)
  jobs10
  stalled-cycles-frontend     233,595,958,008 (  49.81%)    227,540,615,689 (  49.11%)      160,341,979,938 (  43.07%)
  stalled-cycles-backend      136,153,676,021 (  29.03%)    133,635,240,742 (  28.84%)       65,909,135,465 (  17.70%)
  instructions                517,001,168,497 (    1.10)    516,210,976,158 (    1.11)      511,374,038,613 (    1.37)
  branches                     98,911,641,329 ( 585.796)     98,700,069,712 ( 591.583)       97,646,761,028 ( 728.712)
  branch-misses                   232,341,823 (   0.23%)        199,256,308 (   0.20%)          183,135,268 (   0.19%)

per-cpu streams tend to cause significantly less stalled cycles; execute
less branches and hit less branch-misses.

perf stat reported execution time

                          4 streams        8 streams       per-cpu
  ====================================================================
  jobs1
  seconds elapsed        20.909073870     20.875670495    20.817838540
  jobs2
  seconds elapsed        18.529488399     18.720566469    16.356103108
  jobs3
  seconds elapsed        18.991159531     18.991340812    16.766216066
  jobs4
  seconds elapsed        19.560643828     19.551323547    16.246621715
  jobs5
  seconds elapsed        24.746498464     25.221646740    20.696112444
  jobs6
  seconds elapsed        28.258181828     28.289765505    22.885688857
  jobs7
  seconds elapsed        32.632490241     31.909125381    26.272753738
  jobs8
  seconds elapsed        35.651403851     36.027596308    29.108024711
  jobs9
  seconds elapsed        40.569362365     40.024227989    32.898204012
  jobs10
  seconds elapsed        44.673112304     43.874898137    35.632952191

Please see
Link: http://marc.info/?l=linux-kernel&m=146166970727530
Link: http://marc.info/?l=linux-kernel&m=146174716719650
for more test results (under low memory conditions).

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit da9556a2367cf2261ab4d3e100693c82fb1ddb26)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I1af1a466f0ac3f74f9c36f06685111ccef0f4ec4

2 years agoBACKPORT: zsmalloc: require GFP in zs_malloc()
Sergey Senozhatsky [Fri, 20 May 2016 23:59:48 +0000 (16:59 -0700)]
BACKPORT: zsmalloc: require GFP in zs_malloc()

Pass GFP flags to zs_malloc() instead of using a fixed mask supplied to
zs_create_pool(), so we can be more flexible, but, more importantly, we
need this to switch zram to per-cpu compression streams -- zram will try
to allocate handle with preemption disabled in a fast path and switch to
a slow path (using different gfp mask) if the fast one has failed.

Apart from that, this also align zs_malloc() interface with zspool/zbud.

[sergey.senozhatsky@gmail.com: pass GFP flags to zs_malloc() instead of using a fixed mask]
Link: http://lkml.kernel.org/r/20160429150942.GA637@swordfish
Link: http://lkml.kernel.org/r/20160429150942.GA637@swordfish
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit d0d8da2dc49dfdfe1d788eaf4d55eb5d4964d926)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I31276c9351be21a4ed588681b332e98142b76526

2 years agoUPSTREAM: zram/zcomp: do not zero out zcomp private pages
Sergey Senozhatsky [Thu, 14 Jan 2016 23:22:35 +0000 (15:22 -0800)]
UPSTREAM: zram/zcomp: do not zero out zcomp private pages

Do not __GFP_ZERO allocated zcomp ->private pages.  We keep allocated
streams around and use them for read/write requests, so we supply a
zeroed out ->private to compression algorithm as a scratch buffer only
once -- the first time we use that stream.  For the rest of IO requests
served by this stream ->private usually contains some temporarily data
from the previous requests.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit e02d238c9852a91b30da9ea32ce36d1416cdc683)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I911832da703f596998a4139d6033ef1564848c9e

2 years agoUPSTREAM: zram: pass gfp from zcomp frontend to backend
Minchan Kim [Thu, 14 Jan 2016 23:22:32 +0000 (15:22 -0800)]
UPSTREAM: zram: pass gfp from zcomp frontend to backend

Each zcomp backend uses own gfp flag but it's pointless because the
context they could be called is driven by upper layer(ie, zcomp
frontend).  As well, zcomp frondend could call them in different
context.  One context(ie, zram init part) is it should be better to make
sure successful allocation other context(ie, further stream allocation
part for accelarating I/O speed) is just optional so let's pass gfp down
from driver (ie, zcomp frontend) like normal MM convention.

[sergey.senozhatsky@gmail.com: add missing __vmalloc zero and highmem gfps]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 75d8947a36d0c9aedd69118d1f14bf424005c7c2)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I572d0565de5aff94ebe0782eba9d34f9c9862060

2 years agogud: fix mobicore initialization
Stricted [Wed, 28 Aug 2019 15:26:26 +0000 (15:26 +0000)]
gud: fix mobicore initialization

* backported from s9

Change-Id: I48476e899495490ded64a9e173e3daa3c4cdafa0

2 years agovideo: mdnie: fix lux node permissions
Stricted [Mon, 26 Aug 2019 18:03:34 +0000 (18:03 +0000)]
video: mdnie: fix lux node permissions

2 years agovideo: mdnie: Lift RGB tuning restrictions
Christopher N. Hesse [Fri, 27 Jan 2017 23:07:07 +0000 (00:07 +0100)]
video: mdnie: Lift RGB tuning restrictions

Change-Id: Ibbf1efd2aa19a2790773bd84da3364cfeffffe4b

2 years agoBACKPORT: ARM64: dts: msm: Mount the system partition during early init
Swetha Chikkaboraiah [Mon, 10 Jul 2017 06:06:21 +0000 (11:36 +0530)]
BACKPORT: ARM64: dts: msm: Mount the system partition during early init

Add support to early mount system partition so that system
modules can be loaded during early init for msm8226 and msm8974.

Change-Id: I9d75bec6ff9bada5ab2db6de2a58e40323aa6ca2

2 years agofs: ifdef samsung zswap lmkd integration
Michael Benedict [Mon, 26 Aug 2019 15:48:44 +0000 (01:48 +1000)]
fs: ifdef samsung zswap lmkd integration

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agodefconfig: enable zram
Michael Benedict [Mon, 26 Aug 2019 15:39:00 +0000 (01:39 +1000)]
defconfig: enable zram

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agodefconfig: sync
Michael Benedict [Mon, 26 Aug 2019 15:37:03 +0000 (01:37 +1000)]
defconfig: sync

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agocrypto: fix section mismatch
Michael Benedict [Thu, 6 Jun 2019 13:53:14 +0000 (23:53 +1000)]
crypto: fix section mismatch

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agodefconfig: disable crypto_fips
Michael Benedict [Thu, 6 Jun 2019 13:49:37 +0000 (23:49 +1000)]
defconfig: disable crypto_fips

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agoEnable CONFIG_NETFILTER_XT_TARGET_CT
ivanmeler [Tue, 19 Mar 2019 22:35:32 +0000 (22:35 +0000)]
Enable CONFIG_NETFILTER_XT_TARGET_CT
resolves issues with tethering after november security update

2 years agoARM64: configs: Enable support for sdFAT filesystem
ivanmeler [Tue, 19 Mar 2019 22:34:12 +0000 (22:34 +0000)]
ARM64: configs: Enable support for sdFAT filesystem
 * Update default charset for FAT to UTF-8, matching sdFAT's default.

2 years agofs: sdfat: Add MODULE_ALIAS_FS for supported filesystems
Paul Keith [Wed, 28 Mar 2018 17:52:29 +0000 (19:52 +0200)]
fs: sdfat: Add MODULE_ALIAS_FS for supported filesystems

* This is the proper thing to do for filesystem drivers

Change-Id: I109b201d85e324cc0a72c3fcd09df4a3e1703042
Signed-off-by: Paul Keith <javelinanddart@gmail.com>
2 years agofs: sdfat: Add config option to register sdFAT for VFAT
Paul Keith [Fri, 2 Mar 2018 04:10:27 +0000 (05:10 +0100)]
fs: sdfat: Add config option to register sdFAT for VFAT

Change-Id: I72ba7a14b56175535884390e8601960b5d8ed1cf
Signed-off-by: Paul Keith <javelinanddart@gmail.com>
2 years agofs: sdfat: Add config option to register sdFAT for exFAT
Paul Keith [Fri, 2 Mar 2018 03:51:53 +0000 (04:51 +0100)]
fs: sdfat: Add config option to register sdFAT for exFAT

Change-Id: Id57abf0a4bd0b433fecc622eecb383cd4ea29d17
Signed-off-by: Paul Keith <javelinanddart@gmail.com>
2 years agodos2unix bbdpl Kconfig
Michael Benedict [Sat, 24 Aug 2019 15:47:41 +0000 (01:47 +1000)]
dos2unix bbdpl Kconfig

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agoselinux: remove sec_selinux
Michael Benedict [Sat, 25 May 2019 06:57:58 +0000 (16:57 +1000)]
selinux: remove sec_selinux

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agoMTP: force generic mtp driver instead of Samsung one
Fevax [Tue, 12 Sep 2017 23:38:33 +0000 (20:38 -0300)]
MTP: force generic mtp driver instead of Samsung one

2 years agoSelinux: force permissive
ivanmeler [Fri, 24 May 2019 10:32:26 +0000 (10:32 +0000)]
Selinux: force permissive

2 years agosigcontext ifdifed 64bit
Fevax [Thu, 7 Sep 2017 02:59:06 +0000 (23:59 -0300)]
sigcontext ifdifed 64bit

2 years agobattery: sec_battery: export {CURRENT/VOLTAGE}_MAX to sysfs
Jesse Chan [Sat, 21 Apr 2018 07:08:51 +0000 (00:08 -0700)]
battery: sec_battery: export {CURRENT/VOLTAGE}_MAX to sysfs

Change-Id: I54c775bb80c2151bdc69ea9fb53a48a34327bbef

2 years agousb: remove tizen if function
Michael Benedict [Wed, 23 Jan 2019 14:13:18 +0000 (21:13 +0700)]
usb: remove tizen if function

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agofirmware: convert binary to ihex
Michael Benedict [Sat, 24 Aug 2019 15:42:32 +0000 (01:42 +1000)]
firmware: convert binary to ihex

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agodts: import specific dts to each defconfig
Michael Benedict [Fri, 24 May 2019 11:17:51 +0000 (21:17 +1000)]
dts: import specific dts to each defconfig

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agonet: ipv4: only use when knox_ncm is enabled
Michael Benedict [Wed, 6 Jun 2018 15:54:25 +0000 (01:54 +1000)]
net: ipv4: only use when knox_ncm is enabled

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agodefconfig: disable samsung unnecessary security feature
Michael Benedict [Thu, 21 Feb 2019 13:53:30 +0000 (20:53 +0700)]
defconfig: disable samsung unnecessary security feature

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agosource: N950F DSE2
Michael Benedict [Sun, 25 Aug 2019 07:43:22 +0000 (17:43 +1000)]
source: N950F DSE2

2 years agosource: G955F DSE4
Michael Benedict [Sat, 24 Aug 2019 15:39:07 +0000 (01:39 +1000)]
source: G955F DSE4

Signed-off-by: Michael Benedict <michaelbt@live.com>
2 years agosource: G950F DSE4
Michael Benedict [Sat, 24 Aug 2019 15:31:53 +0000 (01:31 +1000)]
source: G950F DSE4

Signed-off-by: Michael Benedict <michaelbt@live.com>
6 years agoMerge 4.4.111 into android-4.4
Greg Kroah-Hartman [Wed, 10 Jan 2018 09:01:18 +0000 (10:01 +0100)]
Merge 4.4.111 into android-4.4

Changes in 4.4.111
x86/kasan: Write protect kasan zero shadow
kernel/acct.c: fix the acct->needcheck check in check_free_space()
crypto: n2 - cure use after free
crypto: chacha20poly1305 - validate the digest size
crypto: pcrypt - fix freeing pcrypt instances
sunxi-rsb: Include OF based modalias in device uevent
fscache: Fix the default for fscache_maybe_release_page()
kernel: make groups_sort calling a responsibility group_info allocators
kernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL
kernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals
kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()
ARC: uaccess: dont use "l" gcc inline asm constraint modifier
Input: elantech - add new icbody type 15
x86/microcode/AMD: Add support for fam17h microcode loading
parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel
x86/tlb: Drop the _GPL from the cpu_tlbstate export
genksyms: Handle string literals with spaces in reference files
module: keep percpu symbols in module's symtab
module: Issue warnings when tainting kernel
proc: much faster /proc/vmstat
Map the vsyscall page with _PAGE_USER
Fix build error in vma.c
Linux 4.4.111

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
6 years agoLinux 4.4.111
Greg Kroah-Hartman [Wed, 10 Jan 2018 08:27:15 +0000 (09:27 +0100)]
Linux 4.4.111

6 years agoFix build error in vma.c
Greg Kroah-Hartman [Tue, 9 Jan 2018 09:24:02 +0000 (10:24 +0100)]
Fix build error in vma.c

This fixes the following much-reported build issue:

arch/x86/entry/vdso/vma.c: In function ‘map_vdso’:
arch/x86/entry/vdso/vma.c:175:9: error:
        implicit declaration of function ‘pvclock_pvti_cpu0_va’

on some arches and configurations.

Thanks to Guenter for being persistent enough to get it fixed :)

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoMap the vsyscall page with _PAGE_USER
Borislav Petkov [Thu, 4 Jan 2018 16:42:45 +0000 (17:42 +0100)]
Map the vsyscall page with _PAGE_USER

This needs to happen early in kaiser_pagetable_walk(), before the
hierarchy is established so that _PAGE_USER permission can be really
set.

A proper fix would be to teach kaiser_pagetable_walk() to update those
permissions but the vsyscall page is the only exception here so ...

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoproc: much faster /proc/vmstat
Alexey Dobriyan [Sat, 8 Oct 2016 00:02:14 +0000 (17:02 -0700)]
proc: much faster /proc/vmstat

commit 68ba0326b4e14988f9e0c24a6e12a85cf2acd1ca upstream.

Every current KDE system has process named ksysguardd polling files
below once in several seconds:

$ strace -e trace=open -p $(pidof ksysguardd)
Process 1812 attached
open("/etc/mtab", O_RDONLY|O_CLOEXEC)   = 8
open("/etc/mtab", O_RDONLY|O_CLOEXEC)   = 8
open("/proc/net/dev", O_RDONLY)         = 8
open("/proc/net/wireless", O_RDONLY)    = -1 ENOENT (No such file or directory)
open("/proc/stat", O_RDONLY)            = 8
open("/proc/vmstat", O_RDONLY)          = 8

Hell knows what it is doing but speed up reading /proc/vmstat by 33%!

Benchmark is open+read+close 1.000.000 times.

BEFORE
$ perf stat -r 10 taskset -c 3 ./proc-vmstat

 Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs):

      13146.768464      task-clock (msec)         #    0.960 CPUs utilized            ( +-  0.60% )
                15      context-switches          #    0.001 K/sec                    ( +-  1.41% )
                 1      cpu-migrations            #    0.000 K/sec                    ( +- 11.11% )
               104      page-faults               #    0.008 K/sec                    ( +-  0.57% )
    45,489,799,349      cycles                    #    3.460 GHz                      ( +-  0.03% )
     9,970,175,743      stalled-cycles-frontend   #   21.92% frontend cycles idle     ( +-  0.10% )
     2,800,298,015      stalled-cycles-backend    #   6.16% backend cycles idle       ( +-  0.32% )
    79,241,190,850      instructions              #    1.74  insn per cycle
                                                  #    0.13  stalled cycles per insn  ( +-  0.00% )
    17,616,096,146      branches                  # 1339.956 M/sec                    ( +-  0.00% )
       176,106,232      branch-misses             #    1.00% of all branches          ( +-  0.18% )

      13.691078109 seconds time elapsed                                          ( +-  0.03% )
      ^^^^^^^^^^^^

AFTER
$ perf stat -r 10 taskset -c 3 ./proc-vmstat

 Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs):

       8688.353749      task-clock (msec)         #    0.950 CPUs utilized            ( +-  1.25% )
                10      context-switches          #    0.001 K/sec                    ( +-  2.13% )
                 1      cpu-migrations            #    0.000 K/sec
               104      page-faults               #    0.012 K/sec                    ( +-  0.56% )
    30,384,010,730      cycles                    #    3.497 GHz                      ( +-  0.07% )
    12,296,259,407      stalled-cycles-frontend   #   40.47% frontend cycles idle     ( +-  0.13% )
     3,370,668,651      stalled-cycles-backend    #  11.09% backend cycles idle       ( +-  0.69% )
    28,969,052,879      instructions              #    0.95  insn per cycle
                                                  #    0.42  stalled cycles per insn  ( +-  0.01% )
     6,308,245,891      branches                  #  726.058 M/sec                    ( +-  0.00% )
       214,685,502      branch-misses             #    3.40% of all branches          ( +-  0.26% )

       9.146081052 seconds time elapsed                                          ( +-  0.07% )
       ^^^^^^^^^^^

vsnprintf() is slow because:

1. format_decode() is busy looking for format specifier: 2 branches
   per character (not in this case, but in others)

2. approximately million branches while parsing format mini language
   and everywhere

3.  just look at what string() does /proc/vmstat is good case because
   most of its content are strings

Link: http://lkml.kernel.org/r/20160806125455.GA1187@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agomodule: Issue warnings when tainting kernel
Libor Pechacek [Wed, 13 Apr 2016 01:36:12 +0000 (11:06 +0930)]
module: Issue warnings when tainting kernel

commit 3205c36cf7d96024626f92d65f560035df1abcb2 upstream.

While most of the locations where a kernel taint bit is set are accompanied
with a warning message, there are two which set their bits silently.  If
the tainting module gets unloaded later on, it is almost impossible to tell
what was the reason for setting the flag.

Signed-off-by: Libor Pechacek <lpechacek@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agomodule: keep percpu symbols in module's symtab
Miroslav Benes [Thu, 26 Nov 2015 02:48:06 +0000 (13:18 +1030)]
module: keep percpu symbols in module's symtab

commit e0224418516b4d8a6c2160574bac18447c354ef0 upstream.

Currently, percpu symbols from .data..percpu ELF section of a module are
not copied over and stored in final symtab array of struct module.
Consequently such symbol cannot be returned via kallsyms API (for
example kallsyms_lookup_name). This can be especially confusing when the
percpu symbol is exported. Only its __ksymtab et al. are present in its
symtab.

The culprit is in layout_and_allocate() function where SHF_ALLOC flag is
dropped for .data..percpu section. There is in fact no need to copy the
section to final struct module, because kernel module loader allocates
extra percpu section by itself. Unfortunately only symbols from
SHF_ALLOC sections are copied due to a check in is_core_symbol().

The patch changes is_core_symbol() function to copy over also percpu
symbols (their st_shndx points to .data..percpu ELF section). We do it
only if CONFIG_KALLSYMS_ALL is set to be consistent with the rest of the
function (ELF section is SHF_ALLOC but !SHF_EXECINSTR). Finally
elf_type() returns type 'a' for a percpu symbol because its address is
absolute.

Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agogenksyms: Handle string literals with spaces in reference files
Michal Marek [Wed, 9 Dec 2015 14:08:21 +0000 (15:08 +0100)]
genksyms: Handle string literals with spaces in reference files

commit a78f70e8d65e88b9f631d073f68cb26dcd746298 upstream.

The reference files use spaces to separate tokens, however, we must
preserve spaces inside string literals. Currently the only case in the
tree is struct edac_raw_error_desc in <linux/edac.h>:

$ KBUILD_SYMTYPES=1 make -s drivers/edac/amd64_edac.symtypes
$ mv drivers/edac/amd64_edac.{symtypes,symref}
$ KBUILD_SYMTYPES=1 make -s drivers/edac/amd64_edac.symtypes
drivers/edac/amd64_edac.c:527: warning: amd64_get_dram_hole_info: modversion changed because of changes in struct edac_raw_error_desc

Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/tlb: Drop the _GPL from the cpu_tlbstate export
Thomas Gleixner [Thu, 4 Jan 2018 21:19:04 +0000 (22:19 +0100)]
x86/tlb: Drop the _GPL from the cpu_tlbstate export

commit 1e5476815fd7f98b888e01a0f9522b63085f96c9 upstream.

The recent changes for PTI touch cpu_tlbstate from various tlb_flush
inlines. cpu_tlbstate is exported as GPL symbol, so this causes a
regression when building out of tree drivers for certain graphics cards.

Aside of that the export was wrong since it was introduced as it should
have been EXPORT_PER_CPU_SYMBOL_GPL().

Use the correct PER_CPU export and drop the _GPL to restore the previous
state which allows users to utilize the cards they payed for.

As always I'm really thrilled to make this kind of change to support the
#friends (or however the hot hashtag of today is spelled) from that closet
sauce graphics corp.

Fixes: 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4")
Fixes: 6fd166aae78c ("x86/mm: Use/Fix PCID to optimize user/kernel switches")
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Backlund <tmb@mageia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoparisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel
Helge Deller [Tue, 2 Jan 2018 19:36:44 +0000 (20:36 +0100)]
parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel

commit 88776c0e70be0290f8357019d844aae15edaa967 upstream.

Qemu for PARISC reported on a 32bit SMP parisc kernel strange failures
about "Not-handled unaligned insn 0x0e8011d6 and 0x0c2011c9."

Those opcodes evaluate to the ldcw() assembly instruction which requires
(on 32bit) an alignment of 16 bytes to ensure atomicity.

As it turns out, qemu is correct and in our assembly code in entry.S and
pacache.S we don't pay attention to the required alignment.

This patch fixes the problem by aligning the lock offset in assembly
code in the same manner as we do in our C-code.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/microcode/AMD: Add support for fam17h microcode loading
Tom Lendacky [Thu, 30 Nov 2017 22:46:40 +0000 (16:46 -0600)]
x86/microcode/AMD: Add support for fam17h microcode loading

commit f4e9b7af0cd58dd039a0fb2cd67d57cea4889abf upstream.

The size for the Microcode Patch Block (MPB) for an AMD family 17h
processor is 3200 bytes.  Add a #define for fam17h so that it does
not default to 2048 bytes and fail a microcode load/update.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20171130224640.15391.40247.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Alice Ferrazzi <alicef@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoInput: elantech - add new icbody type 15
Aaron Ma [Sun, 26 Nov 2017 00:48:41 +0000 (16:48 -0800)]
Input: elantech - add new icbody type 15

commit 10d900303f1c3a821eb0bef4e7b7ece16768fba4 upstream.

The touchpad of Lenovo Thinkpad L480 reports it's version as 15.

Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoARC: uaccess: dont use "l" gcc inline asm constraint modifier
Vineet Gupta [Fri, 8 Dec 2017 16:26:58 +0000 (08:26 -0800)]
ARC: uaccess: dont use "l" gcc inline asm constraint modifier

commit 79435ac78d160e4c245544d457850a56f805ac0d upstream.

This used to setup the LP_COUNT register automatically, but now has been
removed.

There was an earlier fix 3c7c7a2fc8811 which fixed instance in delay.h but
somehow missed this one as gcc change had not made its way into
production toolchains and was not pedantic as it is now !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agokernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()
Oleg Nesterov [Fri, 17 Nov 2017 23:30:08 +0000 (15:30 -0800)]
kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()

commit 426915796ccaf9c2bd9bb06dc5702225957bc2e5 upstream.

complete_signal() checks SIGNAL_UNKILLABLE before it starts to destroy
the thread group, today this is wrong in many ways.

If nothing else, fatal_signal_pending() should always imply that the
whole thread group (except ->group_exit_task if it is not NULL) is
killed, this check breaks the rule.

After the previous changes we can rely on sig_task_ignored();
sig_fatal(sig) && SIGNAL_UNKILLABLE can only be true if we actually want
to kill this task and sig == SIGKILL OR it is traced and debugger can
intercept the signal.

This should hopefully fix the problem reported by Dmitry.  This
test-case

static int init(void *arg)
{
for (;;)
pause();
}

int main(void)
{
char stack[16 * 1024];

for (;;) {
int pid = clone(init, stack + sizeof(stack)/2,
CLONE_NEWPID | SIGCHLD, NULL);
assert(pid > 0);

assert(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0);
assert(waitpid(-1, NULL, WSTOPPED) == pid);

assert(ptrace(PTRACE_DETACH, pid, 0, SIGSTOP) == 0);
assert(syscall(__NR_tkill, pid, SIGKILL) == 0);
assert(pid == wait(NULL));
}
}

triggers the WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)) in
task_participate_group_stop().  do_signal_stop()->signal_group_exit()
checks SIGNAL_GROUP_EXIT and return false, but task_set_jobctl_pending()
checks fatal_signal_pending() and does not set JOBCTL_STOP_PENDING.

And his should fix the minor security problem reported by Kyle,
SECCOMP_RET_TRACE can miss fatal_signal_pending() the same way if the
task is the root of a pid namespace.

Link: http://lkml.kernel.org/r/20171103184246.GD21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Kyle Huey <me@kylehuey.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agokernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals
Oleg Nesterov [Fri, 17 Nov 2017 23:30:04 +0000 (15:30 -0800)]
kernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals

commit ac25385089f673560867eb5179228a44ade0cfc1 upstream.

Change sig_task_ignored() to drop the SIG_DFL && !sig_kernel_only()
signals even if force == T.  This simplifies the next change and this
matches the same check in get_signal() which will drop these signals
anyway.

Link: http://lkml.kernel.org/r/20171103184227.GC21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agokernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL
Oleg Nesterov [Fri, 17 Nov 2017 23:30:01 +0000 (15:30 -0800)]
kernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL

commit 628c1bcba204052d19b686b5bac149a644cdb72e upstream.

The comment in sig_ignored() says "Tracers may want to know about even
ignored signals" but SIGKILL can not be reported to debugger and it is
just wrong to return 0 in this case: SIGKILL should only kill the
SIGNAL_UNKILLABLE task if it comes from the parent ns.

Change sig_ignored() to ignore ->ptrace if sig == SIGKILL and rely on
sig_task_ignored().

SISGTOP coming from within the namespace is not really right too but at
least debugger can intercept it, and we can't drop it here because this
will break "gdb -p 1": ptrace_attach() won't work.  Perhaps we will add
another ->ptrace check later, we will see.

Link: http://lkml.kernel.org/r/20171103184206.GB21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agokernel: make groups_sort calling a responsibility group_info allocators
Thiago Rafael Becker [Thu, 14 Dec 2017 23:33:12 +0000 (15:33 -0800)]
kernel: make groups_sort calling a responsibility group_info allocators

commit bdcf0a423ea1c40bbb40e7ee483b50fc8aa3d758 upstream.

In testing, we found that nfsd threads may call set_groups in parallel
for the same entry cached in auth.unix.gid, racing in the call of
groups_sort, corrupting the groups for that entry and leading to
permission denials for the client.

This patch:
 - Make groups_sort globally visible.
 - Move the call to groups_sort to the modifiers of group_info
 - Remove the call to groups_sort from set_groups

Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.com
Signed-off-by: Thiago Rafael Becker <thiago.becker@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>