nohz: Affine unpinned timers to housekeepers
authorVatika Harlalka <vatikaharlalka@gmail.com>
Tue, 1 Sep 2015 14:50:59 +0000 (16:50 +0200)
committerIngo Molnar <mingo@kernel.org>
Wed, 2 Sep 2015 08:33:22 +0000 (10:33 +0200)
commit9642d18eee2cd169b60c6ac0f20bda745b5a3d1e
tree11ba961bc1366fd72d9ec7f732488f1574d15281
parente713c80a4e49d4bed5324d24755e42bf01c87556
nohz: Affine unpinned timers to housekeepers

The problem addressed in this patch is about affining unpinned
timers. Adaptive or Full Dynticks CPUs are currently disturbed
by unnecessary jitter due to firing of such timers on them.

This patch will affine timers to online CPUs which are not full
dynticks in NOHZ_FULL configured systems. It should not
introduce overhead in nohz full off case due to static keys.

Signed-off-by: Vatika Harlalka <vatikaharlalka@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1441119060-2230-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
include/linux/tick.h
kernel/sched/core.c