Messages in this thread | | | Date | Mon, 24 Feb 2020 17:05:29 +0100 | From | Sebastian Andrzej Siewior <> | Subject | Re: [PATCH RT 15/25] sched: migrate_enable: Use select_fallback_rq() |
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On 2020-02-24 09:31:06 [-0600], Tom Zanussi wrote: > On Mon, 2020-02-24 at 10:43 +0100, Sebastian Andrzej Siewior wrote: > > On 2020-02-21 15:24:43 [-0600], zanussi@kernel.org wrote: > > > From: Scott Wood <swood@redhat.com> > > > > > > v4.14.170-rt75-rc1 stable review patch. > > > If anyone has any objections, please let me know. > > > > This creates bug which is stuffed later via > > sched: migrate_enable: Busy loop until the migration request is > > completed > > > > So if apply this, please take the bug fix, too. This is Stevens queue > > for reference: > > > [PATCH RT 22/30] sched: migrate_enable: Use select_fallback_rq() > > > > ^^ bug introduced > > > > Hmm, it seemed from the comment on the 4.19 series that it was '24/32 > sched: migrate_enable: Use stop_one_cpu_nowait()' that required 'sched: > migrate_enable: Busy loop until the migration request is > completed' as a bug fix. > > https://lore.kernel.org/linux-rt-users/20200122083130.kuu3yppckhyjrr4u@linutronix.de/#t > > I didn't take the stop_one_cpu_nowait() one, so didn't take the busy > loop one either.
Ach, it was the different WARN_ON() then. So this might not introduce any bug then. *Might*. Steven backported the whole pile and you took just this one patch. The whole set was tested in devel and uncovered a problem which was fixed later. Taking only a part *may* expose other problems it *may* be fine.
Steven, any opinion on your side?
> Thanks, > > Tom
Sebastian
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