]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
VM statistics: Make timer deferrable
authorChristoph Lameter <clameter@sgi.com>
Fri, 11 May 2007 05:22:21 +0000 (22:22 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Fri, 11 May 2007 15:29:32 +0000 (08:29 -0700)
commit39bf6270f524bbe2682b56f2a979703abf937dd1
tree0bf7783870d19b223286e1bba3915b90fbe26e30
parent45222b9e02fb282eb0a8007a3d992dd229ec2410
VM statistics: Make timer deferrable

VM statistics updates do not matter if the kernel is in idle powersaving
mode.  So allow the timer to be deferred.

It would be better though if we could switch the timer between deferrable
and nondeferrable based on differentials present.  The timer would start
out nondeferrable and if we find that there were no updates in the last
statistics interval then we would switch the timer to deferrable.  If the
timer later finds again that there are differentials then go to
nondeferrable again.

And yet another way would be to run the timer shortly before going to idle?

The solution here means that the VM counters may be slightly off during
idle since differentials may be still pending while the timer is deferred.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/vmstat.c