The patch titled
swap: do not send discards as barriers
has been added to the -mm tree. Its filename is
swap-do-not-send-discards-as-barriers.patch
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------------------------------------------------------
Subject: swap: do not send discards as barriers
From: Christoph Hellwig <hch@xxxxxxxxxxxxx>
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@xxxxxxxxxx: superflous newlines removed]
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Tested-by: Nigel Cunningham <nigel@xxxxxxxxxxxx>
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jens Axboe <jaxboe@xxxxxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swapfile.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff -puN mm/swapfile.c~swap-do-not-send-discards-as-barriers mm/swapfile.c
--- a/mm/swapfile.c~swap-do-not-send-discards-as-barriers
+++ a/mm/swapfile.c
@@ -139,8 +139,7 @@ static int discard_swap(struct swap_info
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
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
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;
}
_
Patches currently in -mm which might be from hch@xxxxxxxxxxxxx are
linux-next.patch
o_direct-fix-the-splitting-up-of-contiguous-i-o.patch
swap-do-not-send-discards-as-barriers.patch
vmscan-do-not-writeback-filesystem-pages-in-direct-reclaim.patch
vmscan-kick-flusher-threads-to-clean-pages-when-reclaim-is-encountering-dirty-pages.patch
writeback-remove-nonblocking-encountered_congestion-references.patch
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