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| author | Christoph Hellwig <hch@infradead.org> | 2010-09-09 16:38:10 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-09-09 18:57:25 -0700 |
| commit | 8f2ae0faa3a119158c4dcfe89926d6fad5f5332c (patch) | |
| tree | 720272512fd0dfd1d865d2dc64b30fed811f2d13 /mm | |
| parent | b73d7fcecd93dc15eaa3c45c8c587b613f6673c4 (diff) | |
| download | lwn-8f2ae0faa3a119158c4dcfe89926d6fad5f5332c.tar.gz lwn-8f2ae0faa3a119158c4dcfe89926d6fad5f5332c.zip | |
swap: do not send discards as barriers
The swap code already uses synchronous discards, no need to add I/O
barriers.
This fixes the worst of the terrible slowdown in swap allocation for
hibernation, reported on 2.6.35 by Nigel Cunningham; but does not entirely
eliminate that regression.
[tj@kernel.org: superflous newlines removed]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/swapfile.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index ed5151079f59..1894dead0b58 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -139,8 +139,7 @@ static int discard_swap(struct swap_info_struct *si) nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9); if (nr_blocks) { err = blkdev_issue_discard(si->bdev, start_block, - nr_blocks, GFP_KERNEL, - BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER); + nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT); if (err) return err; cond_resched(); @@ -151,8 +150,7 @@ static int discard_swap(struct swap_info_struct *si) nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9); err = blkdev_issue_discard(si->bdev, start_block, - nr_blocks, GFP_KERNEL, - BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER); + nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT); if (err) break; @@ -191,8 +189,7 @@ static void discard_swap_cluster(struct swap_info_struct *si, start_block <<= PAGE_SHIFT - 9; nr_blocks <<= PAGE_SHIFT - 9; if (blkdev_issue_discard(si->bdev, start_block, - nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT | - BLKDEV_IFL_BARRIER)) + nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT)) break; } |