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authorThomas Gleixner <tglx@linutronix.de>2012-03-01 16:16:02 +0100
committerSteven Rostedt <rostedt@rostedt.homelinux.com>2012-10-26 14:31:51 -0400
commit6918bd731188d8ce8ff4edfb9989e3a796503887 (patch)
tree5ae72f21f1bdc685739891c457b12073fdb3daa0
parent3d16ce4a7e8175e17cab340801a28271246168b3 (diff)
net: u64_stat: Protect seqcount
On RT we must prevent that the writer gets preempted inside the write section. Otherwise a preempting reader might spin forever. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable-rt@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--include/linux/u64_stats_sync.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/u64_stats_sync.h b/include/linux/u64_stats_sync.h
index 8da8c4e87da3..b39549fb3c3f 100644
--- a/include/linux/u64_stats_sync.h
+++ b/include/linux/u64_stats_sync.h
@@ -70,6 +70,7 @@ struct u64_stats_sync {
static inline void u64_stats_update_begin(struct u64_stats_sync *syncp)
{
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
+ preempt_disable_rt();
write_seqcount_begin(&syncp->seq);
#endif
}
@@ -78,6 +79,7 @@ static inline void u64_stats_update_end(struct u64_stats_sync *syncp)
{
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
write_seqcount_end(&syncp->seq);
+ preempt_enable_rt();
#endif
}