releases/4.2.4/sched-preempt-powerpc-kvm-use-need_resched-instead-of-should_resched.patch

   1 From c56dadf39761a6157239cac39e3988998c994f98 Mon Sep 17 00:00:00 2001
   2 From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
   3 Date: Wed, 15 Jul 2015 12:52:03 +0300
   4 Subject: sched/preempt, powerpc, kvm: Use need_resched() instead of should_resched()
   5
   6 From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
   7
   8 commit c56dadf39761a6157239cac39e3988998c994f98 upstream.
   9
  10 Function should_resched() is equal to (!preempt_count() && need_resched()).
  11 In preemptive kernel preempt_count here is non-zero because of vc->lock.
  12
  13 Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
  14 Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
  15 Cc: Alexander Graf <agraf@suse.de>
  16 Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
  17 Cc: David Vrabel <david.vrabel@citrix.com>
  18 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  19 Cc: Mike Galbraith <efault@gmx.de>
  20 Cc: Paul Mackerras <paulus@samba.org>
  21 Cc: Peter Zijlstra <peterz@infradead.org>
  22 Cc: Thomas Gleixner <tglx@linutronix.de>
  23 Link: http://lkml.kernel.org/r/20150715095203.12246.72922.stgit@buzz
  24 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  25 Cc: Guenter Roeck <linux@roeck-us.net>
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  27
  28 ---
  29  arch/powerpc/kvm/book3s_hv.c |    2 +-
  30  1 file changed, 1 insertion(+), 1 deletion(-)
  31
  32 --- a/arch/powerpc/kvm/book3s_hv.c
  33 +++ b/arch/powerpc/kvm/book3s_hv.c
  34 @@ -2178,7 +2178,7 @@ static int kvmppc_run_vcpu(struct kvm_ru
  35                 vc->runner = vcpu;
  36                 if (n_ceded == vc->n_runnable) {
  37                         kvmppc_vcore_blocked(vc);
  38 -               } else if (should_resched()) {
  39 +               } else if (need_resched()) {
  40                         vc->vcore_state = VCORE_PREEMPT;
  41                         /* Let something else run */
  42                         cond_resched_lock(&vc->lock);