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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2011-05-16 14:27:31 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2011-05-26 09:42:22 -0700
commit4305ce7894dd38b0633bfc8978437320119223bd (patch)
treeeafe4497236f8dd4ddfdf90fe06a5377912a9c35 /kernel/rcutree.c
parentb5904090c754327ed6c2ecaefed4f7d473df393f (diff)
downloadlinux-4305ce7894dd38b0633bfc8978437320119223bd.tar.gz
rcu: Make rcu_enter_nohz() pay attention to nesting
The old version of rcu_enter_nohz() forced RCU into nohz mode even if
the nesting count was non-zero.  This change causes rcu_enter_nohz()
to hold off for non-zero nesting counts.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutree.c')
-rw-r--r--kernel/rcutree.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 195b3a3313e3..99c6038ad04d 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -324,8 +324,8 @@ void rcu_enter_nohz(void)
 	smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
 	local_irq_save(flags);
 	rdtp = &__get_cpu_var(rcu_dynticks);
-	rdtp->dynticks++;
-	rdtp->dynticks_nesting--;
+	if (--rdtp->dynticks_nesting == 0)
+		rdtp->dynticks++;
 	WARN_ON_ONCE(rdtp->dynticks & 0x1);
 	local_irq_restore(flags);
 }