Messages in this thread Patch in this message | | | Date | Tue, 15 Apr 2014 11:45:44 -0700 | From | tip-bot for Viresh Kumar <> | Subject | [tip:timers/urgent] tick-sched: Don't call update_wall_time() when delta is lesser than tick_period |
| |
Commit-ID: 03e6bdc5c4d0fc166bfd5d3cf749a5a0c1b5b1bd Gitweb: http://git.kernel.org/tip/03e6bdc5c4d0fc166bfd5d3cf749a5a0c1b5b1bd Author: Viresh Kumar <viresh.kumar@linaro.org> AuthorDate: Tue, 15 Apr 2014 10:54:40 +0530 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Tue, 15 Apr 2014 20:26:45 +0200
tick-sched: Don't call update_wall_time() when delta is lesser than tick_period
In tick_do_update_jiffies64() we are processing ticks only if delta is greater than tick_period. This is what we are supposed to do here and it broke a bit with this patch:
commit 47a1b796 (tick/timekeeping: Call update_wall_time outside the jiffies lock)
With above patch, we might end up calling update_wall_time() even if delta is found to be smaller that tick_period. Fix this by returning when the delta is less than tick period.
[ tglx: Made it a 3 liner and massaged changelog ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: linaro-kernel@lists.linaro.org Cc: fweisbec@gmail.com Cc: Arvind.Chauhan@arm.com Cc: linaro-networking@linaro.org Cc: John Stultz <john.stultz@linaro.org> Cc: <stable@vger.kernel.org> # v3.14+ Link: http://lkml.kernel.org/r/80afb18a494b0bd9710975bcc4de134ae323c74f.1397537987.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- kernel/time/tick-sched.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 9f8af69..e947d96 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -84,6 +84,9 @@ static void tick_do_update_jiffies64(ktime_t now) /* Keep the tick_next_period variable up to date */ tick_next_period = ktime_add(last_jiffies_update, tick_period); + } else { + write_sequnlock(&jiffies_lock); + return; } write_sequnlock(&jiffies_lock); update_wall_time();
| |