All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Linux kernel regression tracking (#update)"  <regressions@leemhuis.info>
To: Will Deacon <will@kernel.org>, Waiman Long <longman@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Juri Lelli <juri.lelli@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>,
	linux-kernel@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	qperret@google.com
Subject: Re: [PATCH v10 2/5] sched: Use user_cpus_ptr for saving user provided cpumask in sched_setaffinity()
Date: Fri, 10 Feb 2023 18:15:22 +0100	[thread overview]
Message-ID: <82db210b-c23d-1e59-e3c8-73e1b27cb945@leemhuis.info> (raw)
In-Reply-To: <cc637c44-3217-21f4-8843-66e99249b38c@leemhuis.info>

[TLDR: This mail in primarily relevant for Linux kernel regression
tracking. There afaics is a fix for the regression discussed in this
thread, but it did not use a Link: tag to point to the report, as Linus
and the documentation call for. Things happen, no worries -- but it
forces me to write this mail to make the regression tracking bot aware
of the fix. See link in footer if these mails annoy you.]

On 26.01.23 13:52, Linux kernel regression tracking (#adding) wrote:
> On 17.01.23 17:08, Will Deacon wrote:
>>
>> On Thu, Sep 22, 2022 at 02:00:38PM -0400, Waiman Long wrote:
>>> The user_cpus_ptr field is added by commit b90ca8badbd1 ("sched:
>>> Introduce task_struct::user_cpus_ptr to track requested affinity"). It
>>> is currently used only by arm64 arch due to possible asymmetric CPU
>>> setup. This patch extends its usage to save user provided cpumask
>>> when sched_setaffinity() is called for all arches. With this patch
>>> applied, user_cpus_ptr, once allocated after a successful call to
>>> sched_setaffinity(), will only be freed when the task exits.
>> [...]
>> We've tracked this down as the cause of an arm64 regression in Android and I've
>> reproduced the issue with mainline.
>>
>> Basically, if an arm64 system is booted with "allow_mismatched_32bit_el0" on
>> the command-line, then the arch code will (amongst other things) call
>> force_compatible_cpus_allowed_ptr() and relax_compatible_cpus_allowed_ptr()
>> when exec()'ing a 32-bit or a 64-bit task respectively.
>> [...]
> 
> Thanks for the report. To be sure the issue doesn't fall through the
> cracks unnoticed, I'm adding it to regzbot, the Linux kernel regression
> tracking bot:
> 
> #regzbot ^introduced 8f9ea86fdf99

#regzbot fix: 3fb906e7fabbb5b76c3c
#regzbot ignore-activity

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
That page also explains what to do if mails like this annoy you.

  reply	other threads:[~2023-02-10 17:15 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) [this message]
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 ` [PATCH v10 0/5] sched: Persistent user requested affinity Waiman Long

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=82db210b-c23d-1e59-e3c8-73e1b27cb945@leemhuis.info \
    --to=regressions@leemhuis.info \
    --cc=bristot@redhat.com \
    --cc=bsegall@google.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=hannes@cmpxchg.org \
    --cc=jiangshanlai@gmail.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lizefan.x@bytedance.com \
    --cc=longman@redhat.com \
    --cc=mgorman@suse.de \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=qperret@google.com \
    --cc=regressions@lists.linux.dev \
    --cc=rostedt@goodmis.org \
    --cc=tj@kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=vincent.guittot@linaro.org \
    --cc=vschneid@redhat.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.