Re: [PATCH AUTOSEL for 3.18 36/40] powerpc/xmon: Avoid tripping SMP hardlockup watchdog

[Michael Ellerman]

alexander.levin@xxxxxxxxxxx writes:

> On Thu, Dec 14, 2017 at 12:10:39AM +1100, Michael Ellerman wrote:
>>alexander.levin@xxxxxxxxxxx writes:
>>
>>> From: Nicholas Piggin <npiggin@xxxxxxxxx>
>>>
>>> [ Upstream commit 064996d62a33ffe10264b5af5dca92d54f60f806 ]
>>>
>>> The SMP hardlockup watchdog cross-checks other CPUs for lockups, which
>>> causes xmon headaches because it's assuming interrupts hard disabled
>>> means no watchdog troubles. Try to improve that by calling
>>> touch_nmi_watchdog() in obvious places where secondaries are spinning.
>>>
>>> Also annotate these spin loops with spin_begin/end calls.
>>
>>These macros didn't exist until 4.13, and haven't been backported AFAIK.
>
> But the touch_nmi_watchdog() bits are something we want in stable, right?

I don't think you need them unless you've also back ported
arch/powerpc/kernel/watchdog.c, which I don't think you have.

Maybe Nick can confirm?


Also, I thought 3.18 was EOL?

cheers