nohz: Fix nohz ratelimit
authorPeter Zijlstra <peterz@infradead.org>
Thu, 17 Jun 2010 16:02:37 +0000 (18:02 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Thu, 17 Jun 2010 17:37:29 +0000 (19:37 +0200)
commit3310d4d38fbc514e7b18bd3b1eea8effdd63b5aa
tree14e2a5b6126c9b1341a3d4bf5299545ce4b1999a
parent7e27d6e778cd87b6f2415515d7127eba53fe5d02
nohz: Fix nohz ratelimit

Chris Wedgwood reports that 39c0cbe (sched: Rate-limit nohz) causes a
serial console regression, unresponsiveness, and indeed it does. The
reason is that the nohz code is skipped even when the tick was already
stopped before the nohz_ratelimit(cpu) condition changed.

Move the nohz_ratelimit() check to the other conditions which prevent
long idle sleeps.

Reported-by: Chris Wedgwood <cw@f00f.org>
Tested-by: Brian Bloniarz <bmb@athenacr.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Jef Driesen <jefdriesen@telenet.be>
LKML-Reference: <1276790557.27822.516.camel@twins>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
kernel/time/tick-sched.c