[PATCH 0/3] (Was: [RFC][PATCH] sched: Start stopper early)

From: Oleg Nesterov
Date: Thu Oct 08 2015 - 10:54:25 EST


On 10/07, Peter Zijlstra wrote:
>
> So Heiko reported some 'interesting' fail where stop_two_cpus() got
> stuck in multi_cpu_stop() with one cpu waiting for another that never
> happens.
>
> It _looks_ like the 'other' cpu isn't running and the current best
> theory is that we race on cpu-up and get the stop_two_cpus() call in
> before the stopper task is running.

How about this series? Slightly tested.

Note:

- To me this also looks like a preparation for lg lock removal, no
matter how exactly we will do this.

- We can do more cleanups on top of this. Say remove preempt_disable
in stop_two_cpus().

Oleg.

include/linux/stop_machine.h | 1
kernel/cpu.c | 2 -
kernel/stop_machine.c | 83 +++++++++++++++++++++++++++++--------------
3 files changed, 58 insertions(+), 28 deletions(-)

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