aha/include
Mel Gorman f50de2d381 vmscan: have kswapd sleep for a short interval and double check it should be asleep
After kswapd balances all zones in a pgdat, it goes to sleep.  In the
event of no IO congestion, kswapd can go to sleep very shortly after the
high watermark was reached.  If there are a constant stream of allocations
from parallel processes, it can mean that kswapd went to sleep too quickly
and the high watermark is not being maintained for sufficient length time.

This patch makes kswapd go to sleep as a two-stage process.  It first
tries to sleep for HZ/10.  If it is woken up by another process or the
high watermark is no longer met, it's considered a premature sleep and
kswapd continues work.  Otherwise it goes fully to sleep.

This adds more counters to distinguish between fast and slow breaches of
watermarks.  A "fast" premature sleep is one where the low watermark was
hit in a very short time after kswapd going to sleep.  A "slow" premature
sleep indicates that the high watermark was breached after a very short
interval.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Frans Pop <elendil@planet.nl>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:16 -08:00
..
acpi Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq 2009-12-11 15:59:23 -08:00
asm-generic Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2009-12-14 09:58:24 -08:00
crypto crypto: hash - Remove legacy hash/digest code 2009-10-19 12:53:37 +09:00
drm drm/nouveau: Add DRM driver for NVIDIA GPUs 2009-12-11 21:29:34 +10:00
keys
linux vmscan: have kswapd sleep for a short interval and double check it should be asleep 2009-12-15 08:53:16 -08:00
math-emu
media V4L/DVB (13540): ir-common: Cleanup get key evdev code 2009-12-05 18:42:22 -02:00
mtd Kill jffs2-user.h 2009-06-05 17:31:38 +01:00
net Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2009-12-14 09:58:24 -08:00
pcmcia pcmcia: CodingStyle fixes 2009-12-07 22:23:40 +01:00
rdma trivial: fix typo "to to" in multiple files 2009-09-21 15:14:55 +02:00
rxrpc
scsi Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2009-12-09 19:42:25 -08:00
sound Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2009-12-09 19:43:33 -08:00
trace Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-11 20:49:09 -08:00
video Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2009-12-09 19:43:33 -08:00
xen xen: move Xen-testing predicates to common header 2009-11-04 08:47:24 -08:00
Kbuild