hrtimer: Update active_bases before calling hrtimer_force_reprogram()
authorViresh Kumar <viresh.kumar@linaro.org>
Tue, 14 Apr 2015 21:08:25 +0000 (21:08 +0000)
committerThomas Gleixner <tglx@linutronix.de>
Wed, 22 Apr 2015 15:06:48 +0000 (17:06 +0200)
commitd9f0acdeef48570c4e6159d3108f12b64571392e
tree3ed9766dbae7824de6239d4a773944bfbd144523
parent91e5a2170e795989da9f90c18ba18984f23acc5b
hrtimer: Update active_bases before calling hrtimer_force_reprogram()

'active_bases' indicates which clock-base have active timer. The
intention of this bit field was to avoid evaluating inactive bases. It
was introduced with the introduction of the BOOTTIME and TAI clock
bases, but it was never brought into full use.

We want to use it now, but in __remove_hrtimer() the update happens
after the calling hrtimer_force_reprogram() which has to evaluate all
clock bases for the next expiring timer. So in case the last timer of
a clock base got removed we still see the active bit and therefor
evaluate the clock base for no value. There are further optimizations
possible when active_bases is updated in the right place.

Move the update before the call to hrtimer_force_reprogram()

[ tglx: Massaged changelog ]

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linaro-kernel@lists.linaro.org
Link: http://lkml.kernel.org/r/20150414203500.533438642@linutronix.de
Link: http://lkml.kernel.org/r/c7c8ebcd9ed88bb09d76059c745a1fafb48314e7.1428039899.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
kernel/time/hrtimer.c