Revert "x86, timers: Check for pending timers after (device) interrupts"
authorIngo Molnar <mingo@elte.hu>
Fri, 9 Oct 2009 13:58:20 +0000 (15:58 +0200)
committerIngo Molnar <mingo@elte.hu>
Fri, 9 Oct 2009 13:58:20 +0000 (15:58 +0200)
commite7ab0f7b50bc4688fb5cf65de5d42e3b882fb8d1
tree448411e8204d9020f3d1fbbf7cabcad2932ada6d
parentf5dc37530ba8a35aae0f7f4f13781d1904f71e94
Revert "x86, timers: Check for pending timers after (device) interrupts"

This reverts commit 9bcbdd9c58617f1301dd4f17c738bb9bc73aca70.

The real bug producing LatencyTop latencies has been fixed in:

  f5dc375: sched: Update the clock of runqueue select_task_rq() selected

And the commit being reverted here triggers local timer processing
from every device IRQ. If device IRQs come in at a high frequency,
this could cause a performance regression.

The commit being reverted here purely 'fixed' the reported latency
as a side effect, because CPUs were being moved out of idle more
often.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Frans Pop <elendil@planet.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091008064041.67219b13@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/irq.c
arch/x86/kernel/smp.c