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authorAndrew Morton <akpm@linux-foundation.org>2007-02-28 20:13:21 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-03-01 14:53:38 -0800
commit232ea4d69d81169453344b7d05203425c88d973b (patch)
tree00799a50022f97a93c0e7524752b817399955851 /mm/page-writeback.c
parentb1a316f6f9c54d668df4304ddf935595501ccb25 (diff)
[PATCH] throttle_vm_writeout(): don't loop on GFP_NOFS and GFP_NOIO allocations
throttle_vm_writeout() is designed to wait for the dirty levels to subside. But if the caller holds IO or FS locks, we might be holding up that writeout. So change it to take a single nap to give other devices a chance to clean some memory, then return. 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: <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/page-writeback.c')
-rw-r--r--mm/page-writeback.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index f7e088f5a30..f469e3cd08e 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -296,11 +296,21 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
}
EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr);
-void throttle_vm_writeout(void)
+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);
@@ -317,7 +327,6 @@ void throttle_vm_writeout(void)
}
}
-
/*
* writeback at least _min_pages, and keep writing until the amount of dirty
* memory is less than the background threshold, or until we're all clean.