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From: Thomas Gleixner <tglx@kernel.org>
To: Jaidev Shastri via B4 Relay
	<devnull+jaidevshastri.vt.edu@kernel.org>,
	John Stultz <jstultz@google.com>, Stephen Boyd <sboyd@kernel.org>,
	Miroslav Lichvar <mlichvar@redhat.com>
Cc: linux-kernel@vger.kernel.org, Jaidev Shastri <jaidevshastri@vt.edu>
Subject: Re: [PATCH] clocksource: publish finished_booting with release semantics
Date: Tue, 29 Sep 2026 13:53:40 +0200	[thread overview]
Message-ID: <87wls4i88r.ffs@fw13> (raw)
In-Reply-To: <20260921-mb-clocksource-v1-1-3e1d1b43e90d@vt.edu>

On Mon, Sep 21 2026 at 21:22, Jaidev Shastri via wrote:
> From: Jaidev Shastri <jaidevshastri@vt.edu>
>
> clocksource_done_booting() sets curr_clocksource and then
> finished_booting, both with plain stores under clocksource_mutex.
> clocksource_find_best() tests finished_booting with a plain load before
> it walks clocksource_list.
>
> Set the flag with smp_store_release() and read it with
> smp_load_acquire().
>
> Found with MBCheck, a static herd7-based memory consistency checker.

Unfortunately your tool is missing the point. All callchains which end
up in clocksource_find_best() hold clocksource_mutex. So this
acquire/release is pointless.

Thanks,

        tglx

      reply	other threads:[~2026-09-29 11:53 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-22  1:22 Jaidev Shastri via B4 Relay
2026-09-29 11:53 ` Thomas Gleixner [this message]

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