Thomas Gleixner 8b0b1db013 remove put_cpu_no_resched()
put_cpu_no_resched() is an optimization of put_cpu() which unfortunately
can cause high latencies.

The nfs iostats code uses put_cpu_no_resched() in a code sequence where a
reschedule request caused by an interrupt between the get_cpu() and the
put_cpu_no_resched() can delay the reschedule for at least HZ.

The other users of put_cpu_no_resched() optimize correctly in interrupt
code, but there is no real harm in using the put_cpu() function which is
an alias for preempt_enable().  The extra check of the preemmpt count is
not as critical as the potential source of missing a reschedule.

Debugged in the preempt-rt tree and verified in mainline.

Impact: remove a high latency source

[akpm@linux-foundation.org: build fix]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:48 -07:00
..
2007-05-11 05:38:25 -04:00
2005-04-16 15:20:36 -07:00
2008-04-22 08:56:38 -07:00
2006-06-21 11:19:22 -07:00
2006-06-21 11:19:22 -07:00
2005-04-16 15:20:36 -07:00
2009-03-26 11:01:46 -07:00
2009-06-16 19:47:28 -07:00
2007-05-11 14:55:43 -07:00
2008-02-04 15:42:06 -08:00
2008-02-04 15:42:06 -08:00
2009-04-01 09:50:48 -07:00
2008-04-08 13:51:35 -07:00
2009-03-27 11:11:04 -07:00
2009-03-27 11:11:04 -07:00
2005-04-16 15:20:36 -07:00
2005-04-16 15:20:36 -07:00
2006-12-07 10:48:19 -08:00
2009-06-16 19:47:48 -07:00
2009-04-02 19:04:51 -07:00
2008-10-06 10:43:06 -07:00
2009-04-01 09:50:48 -07:00
2007-05-08 14:51:59 -07:00
2009-03-16 14:12:43 +10:30
2005-04-16 15:20:36 -07:00
2005-04-16 15:20:36 -07:00
2009-03-31 14:25:08 -07:00