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From: Ingo Molnar <mingo@kernel.org>
To: Maksim Davydov <davydov-max@yandex-team.ru>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	den-plotnikov@yandex-team.ru, gpiccoli@igalia.com,
	mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
	tglx@linutronix.de, hpa@zytor.com
Subject: Re: [PATCH v5] x86/split_lock: fix delayed detection enabling
Date: Tue, 18 Mar 2025 21:24:46 +0100	[thread overview]
Message-ID: <Z9nWjlIYHXWYJ0eV@gmail.com> (raw)
In-Reply-To: <20250318144911.10455-1-davydov-max@yandex-team.ru>


* Maksim Davydov <davydov-max@yandex-team.ru> wrote:

> If the warn mode with disabled mitigation mode is used, then on each
> CPU where the split lock occurred detection will be disabled in order to
> make progress and delayed work will be scheduled, which then will enable
> detection back. Now it turns out that all CPUs use one global delayed
> work structure. This leads to the fact that if a split lock occurs on
> several CPUs at the same time (within 2 jiffies), only one CPU will
> schedule delayed work, but the rest will not. The return value of
> schedule_delayed_work_on() would have shown this, but it is not checked
> in the code.

So we already merged the previous version into the locking tree ~10 
days ago and it's all in -next already:

  c929d08df8be ("x86/split_lock: Fix the delayed detection logic")

  https://web.git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=c929d08df8bee855528b9d15b853c892c54e1eee

Is there anything new in your -v5 patch, other than undoing all the 
changelog cleanups I did for the previous version? ;-)

Thanks,

	Ingo

  reply	other threads:[~2025-03-18 20:24 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-18 14:49 [PATCH v5] x86/split_lock: fix delayed detection enabling Maksim Davydov
2025-03-18 20:24 ` Ingo Molnar [this message]
2025-03-18 20:43   ` Maksim Davydov
2025-03-19 19:43     ` Ingo Molnar

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