]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
cpuidle: menu governor: reduce latency on exit
authorCorrado Zoccolo <czoccolo@gmail.com>
Tue, 22 Sep 2009 00:04:09 +0000 (17:04 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 22 Sep 2009 14:17:45 +0000 (07:17 -0700)
commit672917dcc781ead7652a8b11b1fba14e38ac15b8
treec504b7f60737ba8d82eabfa662585d463ae5ea66
parent69d25870f20c4b2563304f2b79c5300dd60a067e
cpuidle: menu governor: reduce latency on exit

Move the state residency accounting and statistics computation off the hot
exit path.

On exit, the need to recompute statistics is recorded, and new statistics
will be computed when menu_select is called again.

The expected effect is to reduce processor wakeup latency from sleep
(C-states).  We are speaking of few hundreds of cycles reduction out of a
several microseconds latency (determined by the hardware transition), so
it is difficult to measure.

Signed-off-by: Corrado Zoccolo <czoccolo@gmail.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Adam Belay <abelay@novell.com
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/cpuidle/governors/menu.c