From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andy Lutomirski <luto@kernel.org>
Date: Mon, 21 Feb 2022 18:44:06 +0000
Subject: Re: [PATCH v2 0/8] kernel/fork: Move thread stack free otu of the scheduler path.
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References: <20220217102406.3697941-1-bigeasy@linutronix.de>
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To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org
Cc: Ben Segall <bsegall@google.com>, Daniel Bristot de Oliveira <bristot@redhat.com>, Dietmar Eggemann <dietmar.eggemann@arm.com>, Ingo Molnar <mingo@redhat.com>, Juri Lelli <juri.lelli@redhat.com>, Peter Zijlstra <peterz@infradead.org>, Steven Rostedt <rostedt@goodmis.org>, Thomas Gleixner <tglx@linutronix.de>, Vincent Guittot <vincent.guittot@linaro.org>

On 2/17/22 02:23, Sebastian Andrzej Siewior wrote:
> This is a follup-up on the patch
>      sched: Delay task stack freeing on RT
>      https://lkml.kernel.org/r/20210928122411.593486363@linutronix.de
> 
> It addresses the review feedback:
> - Decouple stack accounting from its free invocation. The accounting
>    happens in do_exit(), the final free call happens later.
> 
> - Add put_task_stack_sched() to finish_task_switch(). Here the VMAP
>    stack is cached only. If it fails, or in the !VMAP case then the final
>    free happens in delayed_put_task_struct(). This is also an oportunity
>    to cache the stack.
> 
> Changes since v1:
>    - Drop the bit marked und use addtional RCU head to free the stack in
>    case that it can't be cached. Suggested by Andy Lutomirski.

Acked-by: Andy Lutomirski <luto@kernel.org>

This version is much nicer.  Thanks!

--Andy