From 2f6a3bed7347ee94fe57b3501fddaa646a26d890 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Wed, 15 Apr 2015 16:16:03 -0700 Subject: [PATCH] zram: export new 'io_stat' sysfs attrs Per-device `zram/io_stat' file provides accumulated I/O statistics of particular zram device in a format similar to block layer statistics. The file consists of a single line and represents the following stats (separated by whitespace): failed_reads failed_writes invalid_io notify_free Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim Cc: Nitin Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/ABI/testing/sysfs-block-zram | 9 +++++++++ Documentation/blockdev/zram.txt | 11 +++++++++++ drivers/block/zram/zram_drv.c | 20 ++++++++++++++++++++ 3 files changed, 40 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram index 91ad7071b9e8..a7f622f9bcf6 100644 --- a/Documentation/ABI/testing/sysfs-block-zram +++ b/Documentation/ABI/testing/sysfs-block-zram @@ -149,3 +149,12 @@ Description: The compact file is write-only and trigger compaction for allocator zrm uses. The allocator moves some objects so that it could free fragment space. + +What: /sys/block/zram/io_stat +Date: August 2015 +Contact: Sergey Senozhatsky +Description: + The io_stat file is read-only and accumulates device's I/O + statistics not accounted by block layer. For example, + failed_reads, failed_writes, etc. File format is similar to + block layer statistics file format. diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt index 971765ed5ac1..9610be3e9d36 100644 --- a/Documentation/blockdev/zram.txt +++ b/Documentation/blockdev/zram.txt @@ -133,6 +133,17 @@ File /sys/block/zram/stat Represents block layer statistics. Read Documentation/block/stat.txt for details. +File /sys/block/zram/io_stat + +The stat file represents device's I/O statistics not accounted by block +layer and, thus, not available in zram/stat file. It consists of a +single line of text and contains the following stats separated by +whitespace: + failed_reads + failed_writes + invalid_io + notify_free + 8) Deactivate: swapoff /dev/zram0 umount /dev/zram1 diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 35dafd9a0350..1b63a717bdbb 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1033,6 +1033,25 @@ static DEVICE_ATTR_RW(mem_used_max); static DEVICE_ATTR_RW(max_comp_streams); static DEVICE_ATTR_RW(comp_algorithm); +static ssize_t io_stat_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + ssize_t ret; + + down_read(&zram->init_lock); + ret = scnprintf(buf, PAGE_SIZE, + "%8llu %8llu %8llu %8llu\n", + (u64)atomic64_read(&zram->stats.failed_reads), + (u64)atomic64_read(&zram->stats.failed_writes), + (u64)atomic64_read(&zram->stats.invalid_io), + (u64)atomic64_read(&zram->stats.notify_free)); + up_read(&zram->init_lock); + + return ret; +} + +static DEVICE_ATTR_RO(io_stat); ZRAM_ATTR_RO(num_reads); ZRAM_ATTR_RO(num_writes); ZRAM_ATTR_RO(failed_reads); @@ -1060,6 +1079,7 @@ static struct attribute *zram_disk_attrs[] = { &dev_attr_mem_used_max.attr, &dev_attr_max_comp_streams.attr, &dev_attr_comp_algorithm.attr, + &dev_attr_io_stat.attr, NULL, }; -- 2.20.1