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authorThomas Gleixner <tglx@linutronix.de>2012-03-01 16:16:02 +0100
committerClark Williams <williams@redhat.com>2012-03-07 16:15:17 -0600
commitde2e23eea676394b7b6488223ea424f3a83421ca (patch)
treee6a331b48b02ea2be8a36d7f6ff369a1fd5b9cfe /include
parent2113379c232de33524ccba0b118c0c016abcabce (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
Diffstat (limited to 'include')
-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
}