diff options
| author | Fengguang Wu <[email protected]> | 2012-03-21 16:34:09 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2012-03-21 17:54:58 -0700 |
| commit | 47a133339c332f9f8e155c70f5da401aded69948 (patch) | |
| tree | 94f8fb512ebe8e29d0a3f11a04b04004afd4ab59 | |
| parent | 1010bb1b80edb0713415dfe1f97114d320f58c4f (diff) | |
mm: use global_dirty_limit in throttle_vm_writeout()
When starting a memory hog task, a desktop box w/o swap is found to go
unresponsive for a long time. It's solely caused by lots of congestion
waits in throttle_vm_writeout():
gnome-system-mo-4201 553.073384: congestion_wait: throttle_vm_writeout+0x70/0x7f shrink_mem_cgroup_zone+0x48f/0x4a1
gnome-system-mo-4201 553.073386: writeback_congestion_wait: usec_timeout=100000 usec_delayed=100000
gtali-4237 553.080377: congestion_wait: throttle_vm_writeout+0x70/0x7f shrink_mem_cgroup_zone+0x48f/0x4a1
gtali-4237 553.080378: writeback_congestion_wait: usec_timeout=100000 usec_delayed=100000
Xorg-3483 553.103375: congestion_wait: throttle_vm_writeout+0x70/0x7f shrink_mem_cgroup_zone+0x48f/0x4a1
Xorg-3483 553.103377: writeback_congestion_wait: usec_timeout=100000 usec_delayed=100000
The root cause is, the dirty threshold is knocked down a lot by the memory
hog task. Fixed by using global_dirty_limit which decreases gradually on
such events and can guarantee we stay above (the also decreasing) nr_dirty
in the progress of following down to the new dirty threshold.
Signed-off-by: Fengguang Wu <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Greg Thelen <[email protected]>
Cc: Ying Han <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | mm/page-writeback.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 363ba7082ef5..3fc261705b1e 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1472,6 +1472,7 @@ void throttle_vm_writeout(gfp_t gfp_mask) for ( ; ; ) { global_dirty_limits(&background_thresh, &dirty_thresh); + dirty_thresh = hard_dirty_limit(dirty_thresh); /* * Boost the allowable dirty threshold a bit for page |