From: Scott Wood <swood@redhat.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Peter Zijlstra <peterz@infradead.org>,
Juri Lelli <juri.lelli@redhat.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Clark Williams <williams@redhat.com>,
linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org
Subject: Re: [PATCH RT 2/8] sched: __set_cpus_allowed_ptr: Check cpus_mask, not cpus_ptr
Date: Tue, 17 Sep 2019 10:23:58 -0500 [thread overview]
Message-ID: <1bcdec32b7a8165935cffbb2547c3d977c93f26d.camel@redhat.com> (raw)
In-Reply-To: <20190917145729.pul3dmbrdnshne6m@linutronix.de>
On Tue, 2019-09-17 at 16:57 +0200, Sebastian Andrzej Siewior wrote:
> On 2019-07-27 00:56:32 [-0500], Scott Wood wrote:
> > This function is concerned with the long-term cpu mask, not the
> > transitory mask the task might have while migrate disabled. Before
> > this patch, if a task was migrate disabled at the time
> > __set_cpus_allowed_ptr() was called, and the new mask happened to be
> > equal to the cpu that the task was running on, then the mask update
> > would be lost.
>
> lost as in "would not be carried out" I assume.
Right. The old mask would be restored upon migrate_enable() even though
that's no longer the policy that was requested.
-Scott
next prev parent reply other threads:[~2019-09-17 15:24 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-27 5:56 [RT PATCH 0/8] migrate disable fixes and performance Scott Wood
2019-07-27 5:56 ` [PATCH RT 1/8] sched: migrate_enable: Use sleeping_lock to indicate involuntary sleep Scott Wood
2019-07-29 13:26 ` Steven Rostedt
2019-07-27 5:56 ` [PATCH RT 2/8] sched: __set_cpus_allowed_ptr: Check cpus_mask, not cpus_ptr Scott Wood
2019-09-17 14:57 ` Sebastian Andrzej Siewior
2019-09-17 15:23 ` Scott Wood [this message]
2019-07-27 5:56 ` [PATCH RT 3/8] sched: Remove dead __migrate_disabled() check Scott Wood
2019-07-27 5:56 ` [PATCH RT 4/8] sched: migrate disable: Protect cpus_ptr with lock Scott Wood
2019-09-26 16:39 ` Sebastian Andrzej Siewior
2019-09-26 16:52 ` Scott Wood
2019-09-27 12:19 ` Sebastian Andrzej Siewior
2019-09-27 20:02 ` Scott Wood
2019-07-27 5:56 ` [PATCH RT 5/8] sched/deadline: Reclaim cpuset bandwidth in .migrate_task_rq() Scott Wood
2019-09-17 15:10 ` Sebastian Andrzej Siewior
2019-09-27 8:11 ` Juri Lelli
2019-09-27 16:40 ` Scott Wood
2019-09-30 7:12 ` Juri Lelli
2019-09-30 16:24 ` Scott Wood
2019-10-01 8:52 ` Juri Lelli
2019-10-09 6:25 ` Scott Wood
2019-10-09 7:27 ` Juri Lelli
2019-10-09 19:12 ` Scott Wood
2019-10-10 8:18 ` Juri Lelli
2019-07-27 5:56 ` [PATCH RT 6/8] sched: migrate_enable: Set state to TASK_RUNNING Scott Wood
2019-09-17 15:31 ` Sebastian Andrzej Siewior
2019-09-17 17:54 ` Scott Wood
2019-07-27 5:56 ` [PATCH RT 7/8] sched: migrate_enable: Use select_fallback_rq() Scott Wood
2019-09-17 16:00 ` Sebastian Andrzej Siewior
2019-09-24 18:05 ` Scott Wood
2019-07-27 5:56 ` [PATCH RT 8/8] sched: Lazy migrate_disable processing Scott Wood
2019-09-17 16:50 ` Sebastian Andrzej Siewior
2019-09-17 17:06 ` Scott Wood
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