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authorOlof Johansson <olof@lixom.net>2014-07-20 01:59:07 +0400
committerOlof Johansson <olof@lixom.net>2014-07-20 01:59:07 +0400
commit4e9816d012dbc28dc89559261c6ffbf8ffc440dd (patch)
treedee9f8b31f3d6d2fb141541da88e1cc1329b017e /kernel/rcu/update.c
parentda98f44f27d81d7fe9a41f69af4fe08c18d13b56 (diff)
parent1795cd9b3a91d4b5473c97f491d63892442212ab (diff)
downloadlinux-4e9816d012dbc28dc89559261c6ffbf8ffc440dd.tar.xz
Merge tag 'v3.16-rc5' into next/fixes-non-critical
Linux 3.16-rc5
Diffstat (limited to 'kernel/rcu/update.c')
-rw-r--r--kernel/rcu/update.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 4c0a9b0af469..a2aeb4df0f60 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -320,6 +320,18 @@ int rcu_jiffies_till_stall_check(void)
return till_stall_check * HZ + RCU_STALL_DELAY_DELTA;
}
+void rcu_sysrq_start(void)
+{
+ if (!rcu_cpu_stall_suppress)
+ rcu_cpu_stall_suppress = 2;
+}
+
+void rcu_sysrq_end(void)
+{
+ if (rcu_cpu_stall_suppress == 2)
+ rcu_cpu_stall_suppress = 0;
+}
+
static int rcu_panic(struct notifier_block *this, unsigned long ev, void *ptr)
{
rcu_cpu_stall_suppress = 1;
@@ -338,3 +350,21 @@ static int __init check_cpu_stall_init(void)
early_initcall(check_cpu_stall_init);
#endif /* #ifdef CONFIG_RCU_STALL_COMMON */
+
+/*
+ * Hooks for cond_resched() and friends to avoid RCU CPU stall warnings.
+ */
+
+DEFINE_PER_CPU(int, rcu_cond_resched_count);
+
+/*
+ * Report a set of RCU quiescent states, for use by cond_resched()
+ * and friends. Out of line due to being called infrequently.
+ */
+void rcu_resched(void)
+{
+ preempt_disable();
+ __this_cpu_write(rcu_cond_resched_count, 0);
+ rcu_note_context_switch(smp_processor_id());
+ preempt_enable();
+}