From: Andy Lutomirski <luto@kernel.org>
To: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: Re: [patch 4/5] sched: Delay task stack freeing on RT
Date: Fri, 1 Oct 2021 12:02:19 -0700 [thread overview]
Message-ID: <CALCETrXk0i50vyWwou0AT0jtb7V2pqZiJW_7_dqrthi1N19qeg@mail.gmail.com> (raw)
In-Reply-To: <CALCETrU7Fu7BA+DEk8HJPRkqsOSsC-NXR2tPsxW6VFF0pxSS6A@mail.gmail.com>
On Fri, Oct 1, 2021 at 11:48 AM Andy Lutomirski <luto@kernel.org> wrote:
>
> On Fri, Oct 1, 2021 at 10:24 AM Thomas Gleixner <tglx@linutronix.de> wrote:
> >
> ISTM it would be conceptually for do_exit() to handle its own freeing
> in its own preemptible context. Obviously that can't really work,
> since we can't free a task_struct or a task stack while we're running
> on it. But I wonder if we could approximate it by putting this work
> in a workqueue so that it all runs in a normal schedulable context.
> To make the shell script case work nicely, we want to release the task
> stack before notifying anyone waiting for the dying task to exit, but
> maybe that's doable. It could involve some nasty exit_signal hackery,
> though.
I'm making this way more complicated than it needs to be. How about
we unaccount the task stack in do_exit and release it for real in
finish_task_switch()? Other than accounting, free_thread_stack
doesn't take any locks.
--Andy
next prev parent reply other threads:[~2021-10-01 19:02 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-28 12:24 [patch 0/5] sched: Miscellaneous RT related tweaks Thomas Gleixner
2021-09-28 12:24 ` [patch 1/5] sched: Limit the number of task migrations per batch on RT Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
2021-09-28 12:24 ` [patch 2/5] sched: Disable TTWU_QUEUE " Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
2021-09-28 12:24 ` [patch 3/5] sched: Move kprobes cleanup out of finish_task_switch() Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
2021-09-28 12:24 ` [patch 4/5] sched: Delay task stack freeing on RT Thomas Gleixner
2021-09-29 11:54 ` Peter Zijlstra
2021-10-01 16:12 ` Andy Lutomirski
2021-10-01 17:24 ` Thomas Gleixner
2021-10-01 18:48 ` Andy Lutomirski
2021-10-01 19:02 ` Andy Lutomirski [this message]
2021-10-01 20:54 ` Thomas Gleixner
2021-09-28 12:24 ` [patch 5/5] sched: Move mmdrop to RCU " Thomas Gleixner
2021-09-29 12:02 ` Peter Zijlstra
2021-09-29 13:05 ` Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
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