context_tracking: Optimize main APIs off case with static key
authorFrederic Weisbecker <fweisbec@gmail.com>
Wed, 10 Jul 2013 00:44:35 +0000 (02:44 +0200)
committerFrederic Weisbecker <fweisbec@gmail.com>
Wed, 14 Aug 2013 15:14:45 +0000 (17:14 +0200)
commitad65782fba507d91a0a98f519b59e79cac1b474c
tree72e075f00818a0e29bc0874a0ce9ae48c5784614
parent65f382fd0c8fa483713c0971de9f1dfb4cf1ad9c
context_tracking: Optimize main APIs off case with static key

Optimize user and exception entry/exit APIs with static
keys. This minimize the overhead for those who enable
CONFIG_NO_HZ_FULL without always using it. Having no range
passed to nohz_full= should result in the probes to be nopped
(at least we hope so...).

If this proves not be enough in the long term, we'll need
to bring an exception slow path by re-routing the exception
handlers.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
include/linux/context_tracking.h
kernel/context_tracking.c