Re: [PATCH RT 4/8] sched: migrate disable: Protect cpus_ptr with lock

From: Scott Wood
Date: Fri Sep 27 2019 - 16:03:09 EST


On Fri, 2019-09-27 at 14:19 +0200, Sebastian Andrzej Siewior wrote:
> On 2019-09-26 11:52:42 [-0500], Scott Wood wrote:
> > Looks good, thanks!
>
> Thanks, just released.
> Moving forward. It would be nice to have some DL-dev feedback on DL
> patch. For the remaining once, could please throw Steven's
> stress-test-hostplug-cpu-script? If that one does not complain I don't
> see a reason why not apply the patches (since they improve performance
> and do not break anything while doing so).

I'd been using a quick-and-dirty script that does something similar, and ran
it along with rcutorture, a kernel build, and something that randomly
changes affinities -- though with these loads I have to ignore occasional
RCU forward progress complaints that Paul said were expected with this
version of the RCU code, XFS warnings that happen even on unmodified non-RT,
and sometimes a transitory netdev timeout that is not that surprising given
the heavy load and affinity stress (I get it without these patches as well,
though it takes longer).

I just ran Steven's script (both alone and with the other stuff above) and
saw no difference.

-Scott