3.14-stable review patch. If anyone has any objections, please let me know.
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From: Viresh Kumar viresh.kumar@linaro.org
commit 03e6bdc5c4d0fc166bfd5d3cf749a5a0c1b5b1bd upstream.
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 Link: http://lkml.kernel.org/r/80afb18a494b0bd9710975bcc4de134ae323c74f.1397537987... Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/time/tick-sched.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -84,6 +84,9 @@ static void tick_do_update_jiffies64(kti
/* 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();