From 98cc093cba1e925eb34963dedb5f1684f1bdb2f4 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 6 Sep 2017 16:22:27 -0700 Subject: [PATCH] block, THP: make block_device_operations.rw_page support THP The .rw_page in struct block_device_operations is used by the swap subsystem to read/write the page contents from/into the corresponding swap slot in the swap device. To support the THP (Transparent Huge Page) swap optimization, the .rw_page is enhanced to support to read/write THP if possible. Link: http://lkml.kernel.org/r/20170724051840.2309-6-ying.huang@intel.com Signed-off-by: "Huang, Ying" Reviewed-by: Ross Zwisler [for brd.c, zram_drv.c, pmem.c] Cc: Johannes Weiner Cc: Minchan Kim Cc: Dan Williams Cc: Vishal L Verma Cc: Jens Axboe Cc: "Kirill A . Shutemov" Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Michal Hocko Cc: Rik van Riel Cc: Shaohua Li Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/brd.c | 6 ++++- drivers/block/zram/zram_drv.c | 2 ++ drivers/nvdimm/btt.c | 4 +++- drivers/nvdimm/pmem.c | 41 +++++++++++++++++++++++++---------- 4 files changed, 40 insertions(+), 13 deletions(-) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 104b71c0490d..5d9ed0616413 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -326,7 +326,11 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector, struct page *page, bool is_write) { struct brd_device *brd = bdev->bd_disk->private_data; - int err = brd_do_bvec(brd, page, PAGE_SIZE, 0, is_write, sector); + int err; + + if (PageTransHuge(page)) + return -ENOTSUPP; + err = brd_do_bvec(brd, page, PAGE_SIZE, 0, is_write, sector); page_endio(page, is_write, err); return err; } diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 4ddc18a0a04f..4a0438c4ef2a 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1285,6 +1285,8 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector, struct zram *zram; struct bio_vec bv; + if (PageTransHuge(page)) + return -ENOTSUPP; zram = bdev->bd_disk->private_data; if (!valid_io_request(zram, sector, PAGE_SIZE)) { diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index 14323faf8bd9..60491641a8d6 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1241,8 +1241,10 @@ static int btt_rw_page(struct block_device *bdev, sector_t sector, { struct btt *btt = bdev->bd_disk->private_data; int rc; + unsigned int len; - rc = btt_do_bvec(btt, NULL, page, PAGE_SIZE, 0, is_write, sector); + len = hpage_nr_pages(page) * PAGE_SIZE; + rc = btt_do_bvec(btt, NULL, page, len, 0, is_write, sector); if (rc == 0) page_endio(page, is_write, 0); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index f7099adaabc0..e9aa453da50c 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -80,22 +80,40 @@ static blk_status_t pmem_clear_poison(struct pmem_device *pmem, static void write_pmem(void *pmem_addr, struct page *page, unsigned int off, unsigned int len) { - void *mem = kmap_atomic(page); - - memcpy_flushcache(pmem_addr, mem + off, len); - kunmap_atomic(mem); + unsigned int chunk; + void *mem; + + while (len) { + mem = kmap_atomic(page); + chunk = min_t(unsigned int, len, PAGE_SIZE); + memcpy_flushcache(pmem_addr, mem + off, chunk); + kunmap_atomic(mem); + len -= chunk; + off = 0; + page++; + pmem_addr += PAGE_SIZE; + } } static blk_status_t read_pmem(struct page *page, unsigned int off, void *pmem_addr, unsigned int len) { + unsigned int chunk; int rc; - void *mem = kmap_atomic(page); - - rc = memcpy_mcsafe(mem + off, pmem_addr, len); - kunmap_atomic(mem); - if (rc) - return BLK_STS_IOERR; + void *mem; + + while (len) { + mem = kmap_atomic(page); + chunk = min_t(unsigned int, len, PAGE_SIZE); + rc = memcpy_mcsafe(mem + off, pmem_addr, chunk); + kunmap_atomic(mem); + if (rc) + return BLK_STS_IOERR; + len -= chunk; + off = 0; + page++; + pmem_addr += PAGE_SIZE; + } return BLK_STS_OK; } @@ -188,7 +206,8 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector, struct pmem_device *pmem = bdev->bd_queue->queuedata; blk_status_t rc; - rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, sector); + rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE, + 0, is_write, sector); /* * The ->rw_page interface is subtle and tricky. The core -- 2.20.1