From 6807b1db8233ed84671f061b5d825622233df303 Mon Sep 17 00:00:00 2001 From: Kevin Easton Date: Tue, 24 Feb 2015 23:57:07 -0500 Subject: Reduce lock contention in __tz_convert() [BZ #16145] (partial fix) This patch is an "easy win" partial fix for BZ #16145, which notes the heavy contention on tzset_lock when multiple threads are converting times with localtime_r(). In __tz_convert(), the lock does not need to be held after __tzfile_compute() / __tz_compute() have been called, so we can move the unlock up. At this point there is still significant work to be done in __offtime(), so we see some improvement (in my testing with 8 cores banging on localtime_r(), ~20% improvement in throughput). --- time/tzset.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'time') diff --git a/time/tzset.c b/time/tzset.c index 8bc7a2e..82324ca 100644 --- a/time/tzset.c +++ b/time/tzset.c @@ -644,6 +644,8 @@ __tz_convert (const time_t *timer, int use_localtime, struct tm *tp) leap_extra_secs = 0; } + __libc_lock_unlock (tzset_lock); + if (tp) { if (! use_localtime) @@ -659,8 +661,6 @@ __tz_convert (const time_t *timer, int use_localtime, struct tm *tp) tp = NULL; } - __libc_lock_unlock (tzset_lock); - return tp; } -- cgit v1.1