linux_dsm_epyc7002/include
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
..
acpi Merge branch 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel 2009-04-28 17:21:20 -07:00
asm-generic Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 2009-06-15 03:02:23 -07:00
crypto
drm Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2009-06-12 18:09:18 -07:00
keys
linux remove put_cpu_no_resched() 2009-06-16 19:47:48 -07:00
math-emu
media V4L/DVB (11381): ivtv/cx18: remove VIDIOC_INT_S_AUDIO_ROUTING debug support. 2009-04-06 21:44:28 -03:00
mtd
net pkt_sched: Rename PSCHED_US2NS and PSCHED_NS2US 2009-06-15 02:31:47 -07:00
pcmcia
rdma
rxrpc
scsi Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 2009-06-15 03:02:23 -07:00
sound Merge branch 'topic/pcm-jiffies-check' into for-linus 2009-06-10 07:26:41 +02:00
trace Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 2009-06-15 03:02:23 -07:00
video fb: add support of LCD display controller on pxa168/910 (base layer) 2009-06-13 00:09:09 +08:00
xen
Kbuild