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| author | Fengguang Wu <wfg@mail.ustc.edu.cn> | 2007-10-16 23:30:45 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-17 08:43:02 -0700 |
| commit | 369f2389e7d03022abdd25e298bffb9613cd0e54 (patch) | |
| tree | 1071020428c8e3eaa88642682e234de95e7a77bc | |
| parent | 1c0eeaf5698597146ed9b873e2f9e0961edcf0f9 (diff) | |
| download | linux-369f2389e7d03022abdd25e298bffb9613cd0e54.tar.gz linux-369f2389e7d03022abdd25e298bffb9613cd0e54.tar.bz2 linux-369f2389e7d03022abdd25e298bffb9613cd0e54.zip | |
writeback: remove unnecessary wait in throttle_vm_writeout()
We don't want to introduce pointless delays in throttle_vm_writeout() when
the writeback limits are not yet exceeded, do we?
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Greg KH <greg@kroah.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/page-writeback.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index d8c21e5a1bc9..7845462064f4 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -502,16 +502,6 @@ void throttle_vm_writeout(gfp_t gfp_mask) long background_thresh; long dirty_thresh; - if ((gfp_mask & (__GFP_FS|__GFP_IO)) != (__GFP_FS|__GFP_IO)) { - /* - * The caller might hold locks which can prevent IO completion - * or progress in the filesystem. So we cannot just sit here - * waiting for IO to complete. - */ - congestion_wait(WRITE, HZ/10); - return; - } - for ( ; ; ) { get_dirty_limits(&background_thresh, &dirty_thresh, NULL, NULL); @@ -525,6 +515,14 @@ void throttle_vm_writeout(gfp_t gfp_mask) global_page_state(NR_WRITEBACK) <= dirty_thresh) break; congestion_wait(WRITE, HZ/10); + + /* + * The caller might hold locks which can prevent IO completion + * or progress in the filesystem. So we cannot just sit here + * waiting for IO to complete. + */ + if ((gfp_mask & (__GFP_FS|__GFP_IO)) != (__GFP_FS|__GFP_IO)) + break; } } |