From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Juri Lelli <juri.lelli@redhat.com>,
Ingo Molnar <mingo@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Valentin Schneider <vschneid@redhat.com>,
Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Will Deacon <will@kernel.org>
Subject: Re: [PATCH v10 0/5] sched: Persistent user requested affinity
Date: Thu, 6 Oct 2022 17:31:11 -0400 [thread overview]
Message-ID: <9777b2f5-2dae-679e-4fe6-f5019ac7a18f@redhat.com> (raw)
In-Reply-To: <20220922180041.1768141-1-longman@redhat.com>
On 9/22/22 14:00, Waiman Long wrote:
> v10:
> - Squash patches 4, 5 & 6 together into a single patch as suggested
> by PeterZ.
>
> v9:
> - Fix non-SMP config build errors in patch 4 reported by kernel test
> robot.
> - Disable user_cpus_ptr masking also when any of the SCA_MIGRATE_*
> flags are set.
>
> v8:
> - Add patches "sched: Introduce affinity_context structure" and
> "sched: Always clear user_cpus_ptr in do_set_cpus_allowed()" as
> suggested by PeterZ.
> - Better handle cpuset and sched_setaffinity() race in patch 5.
>
> v7:
> - Make changes recommended by Peter such as making scratch_mask
> allocation earlier and using percpu variable to pass information.
>
> The user_cpus_ptr field is added by commit b90ca8badbd1 ("sched:
> Introduce task_struct::user_cpus_ptr to track requested affinity")
> which uses it narrowly to allow keeping cpus affinity intact with
> asymmetric cpu setup.
>
> This patchset extends user_cpus_ptr to store user requested cpus affinity
> via the sched_setaffinity() API. With that information available, it will
> enable cpuset and other callers of set_cpus_allowed_ptr() like hotplug
> to keep cpus afinity as close to what the user wants as possible within
> the cpu list constraint of the current cpuset. Otherwise some change
> to the cpuset hierarchy or a hotplug event may reset the cpumask of
> the tasks in the affected cpusets to the default cpuset value even if
> those tasks have cpus affinity explicitly set by the users before.
>
> It also means that once sched_setaffinity() is called successfully,
> user_cpus_ptr will remain allocated until the task exits except in some
> rare circumstances.
>
> Waiman Long (5):
> sched: Add __releases annotations to affine_move_task()
> sched: Use user_cpus_ptr for saving user provided cpumask in
> sched_setaffinity()
> sched: Enforce user requested affinity
> sched: Handle set_cpus_allowed_ptr(), sched_setaffinity() & other
> races
> sched: Always clear user_cpus_ptr in do_set_cpus_allowed()
>
> kernel/sched/core.c | 231 +++++++++++++++++++++++++---------------
> kernel/sched/deadline.c | 7 +-
> kernel/sched/sched.h | 22 +++-
> 3 files changed, 169 insertions(+), 91 deletions(-)
>
Peter, do you have any further suggestion on how to improve this series?
Thanks,
Longman
prev parent reply other threads:[~2022-10-06 21:31 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-22 18:00 [PATCH v10 0/5] sched: Persistent user requested affinity Waiman Long
2022-09-22 18:00 ` [PATCH v10 1/5] sched: Add __releases annotations to affine_move_task() Waiman Long
2022-10-28 6:42 ` [tip: sched/core] " tip-bot2 for Waiman Long
2022-09-22 18:00 ` [PATCH v10 2/5] sched: Use user_cpus_ptr for saving user provided cpumask in sched_setaffinity() Waiman Long
2022-10-28 6:42 ` [tip: sched/core] sched: Always preserve the user requested cpumask tip-bot2 for Waiman Long
2023-01-17 16:08 ` [PATCH v10 2/5] sched: Use user_cpus_ptr for saving user provided cpumask in sched_setaffinity() Will Deacon
2023-01-17 18:13 ` Waiman Long
2023-01-20 17:59 ` Will Deacon
2023-01-20 18:10 ` Waiman Long
2023-01-26 12:52 ` Linux kernel regression tracking (#adding)
2023-02-10 17:15 ` Linux kernel regression tracking (#update)
2023-01-27 18:36 ` Peter Zijlstra
2023-01-27 19:09 ` Waiman Long
2022-09-22 18:00 ` [PATCH v10 3/5] sched: Enforce user requested affinity Waiman Long
2022-10-07 10:01 ` Peter Zijlstra
2022-10-07 14:57 ` Waiman Long
2022-10-07 15:23 ` Waiman Long
2022-10-28 6:42 ` [tip: sched/core] " tip-bot2 for Waiman Long
2022-09-22 18:00 ` [PATCH v10 4/5] sched: Handle set_cpus_allowed_ptr(), sched_setaffinity() & other races Waiman Long
2022-10-07 12:47 ` Peter Zijlstra
2022-10-07 18:59 ` Waiman Long
2022-10-28 6:42 ` [tip: sched/core] sched: Introduce affinity_context tip-bot2 for Waiman Long
2022-09-22 18:00 ` [PATCH v10 5/5] sched: Always clear user_cpus_ptr in do_set_cpus_allowed() Waiman Long
2022-10-28 6:42 ` [tip: sched/core] " tip-bot2 for Waiman Long
2022-10-06 21:31 ` Waiman Long [this message]
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