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authorChristoph Hellwig <hch@infradead.org>2010-09-09 16:38:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-09-09 18:57:25 -0700
commit8f2ae0faa3a119158c4dcfe89926d6fad5f5332c (patch)
tree720272512fd0dfd1d865d2dc64b30fed811f2d13
parentb73d7fcecd93dc15eaa3c45c8c587b613f6673c4 (diff)
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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>
-rw-r--r--mm/swapfile.c9
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;
}