sched/clock: Delay switching sched_clock to stable
authorPeter Zijlstra <peterz@infradead.org>
Thu, 15 Dec 2016 12:35:52 +0000 (13:35 +0100)
committerIngo Molnar <mingo@kernel.org>
Sat, 14 Jan 2017 10:29:59 +0000 (11:29 +0100)
commit9881b024b7d7671f6a014091bc96506b89081802
tree83319d1a51c4e7a880c329aaca38d9833dc8d4ce
parent555570d744f8150d3fce6083f144026cd1e63627
sched/clock: Delay switching sched_clock to stable

Currently we switch to the stable sched_clock if we guess the TSC is
usable, and then switch back to the unstable path if it turns out TSC
isn't stable during SMP bringup after all.

Delay switching to the stable path until after SMP bringup is
complete. This way we'll avoid switching during the time we detect the
worst of the TSC offences.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
include/linux/sched.h
init/main.c
kernel/sched/clock.c
kernel/sched/core.c