From: Frederic Weisbecker <frederic@kernel.org>
To: Kunwu Chan <kunwu.chan@gmail.com>
Cc: arnd@arndb.de, anna-maria@linutronix.de, mingo@kernel.org,
tglx@kernel.org, linux-arch@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] timers/nohz: Mark got_idle_tick accesses as same-CPU races
Date: Mon, 5 Oct 2026 16:54:14 +0200 [thread overview]
Message-ID: <asO6FntKFaxnTYX2@localhost.localdomain> (raw)
In-Reply-To: <20261002151757.3605081-3-kunwu.chan@gmail.com>
Le Fri, Oct 02, 2026 at 11:17:56PM +0800, Kunwu Chan a écrit :
> got_idle_tick is a per-CPU flag set by the tick interrupt handler in
> tick_sched_do_timer() and read and cleared by the idle path in
> tick_nohz_idle_got_tick(). The flag is intentionally accessed without
> ordering or locking; a concurrent set can be overwritten by the clear.
>
> Use WRITE_ONCE_THIS_CPU() and READ_ONCE_THIS_CPU() to identify these
> as intentional races between execution contexts on the same CPU,
> rather than accesses that may race across CPUs.
>
> Suggested-by: Thomas Gleixner <tglx@kernel.org>
> Signed-off-by: Kunwu Chan <kunwu.chan@gmail.com>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
--
Frederic Weisbecker
SUSE Labs
prev parent reply other threads:[~2026-10-05 14:54 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-02 15:17 [PATCH v2 0/2] rwonce: Introduce {READ,WRITE}_ONCE_THIS_CPU() Kunwu Chan
2026-10-02 15:17 ` [PATCH v2 1/2] rwonce: Add READ_ONCE_THIS_CPU() and WRITE_ONCE_THIS_CPU() Kunwu Chan
2026-10-02 15:44 ` Paul E. McKenney
2026-10-05 14:47 ` Frederic Weisbecker
2026-10-07 2:17 ` KunWu Chan
2026-10-02 15:17 ` [PATCH v2 2/2] timers/nohz: Mark got_idle_tick accesses as same-CPU races Kunwu Chan
2026-10-05 14:54 ` Frederic Weisbecker [this message]
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