From nobody Mon Feb 9 08:36:26 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 22C28221570 for ; Thu, 6 Mar 2025 20:00:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741291203; cv=none; b=qZXlCVhFSFBqXujCSH2iW6m5kBZaNi50KWVGzIl/8FylALAVp3t9Gf+saKOsYZjTN6Y9SIgNe0pmk4U1/+028OPt/WooQunCFgO4s9alS0vvqNlOesBOQ4iarSbJiCWVgKz4cUf9fOdinTbx23qLwbEXaGwzkH7GdKoKxakF+mE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741291203; c=relaxed/simple; bh=CGu5XrruTaOTWbm+H8SU4/LST9GYJ3CBnT53RdCtMCo=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=kv0PHlCH4jRcu7dTh+OS36A3+T/TsQJfeBwkoM0uYn95Gqldx7kD78tNni5EjTrMYE/kmrTe/+Bo0xnyiWd/ybWTN/5vrABj/yO3wqknGfXa91CKvmQL+CNiIBmlLOl8r1aq1e6hiZY33Pz6w20tTxJB8kvbyBAWSIVZCtBspHg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ujJIvMiR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ujJIvMiR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 992E7C4CEE0; Thu, 6 Mar 2025 20:00:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741291202; bh=CGu5XrruTaOTWbm+H8SU4/LST9GYJ3CBnT53RdCtMCo=; h=Date:From:To:Cc:Subject:Reply-To:From; b=ujJIvMiRCwg43DdCgvoXborsFW6ccPLXvstqOQDcaVVADB9Id894sd34tIrE7iQbe 9sYH5XQDxM3+Wpwy0857u1R0vQWEc52tPgQvgtGoNKRN6Oo1Y4yIsuIcOdo3JJ1TnL 28NRoPTW0dOchpxkc7gmQDnYskRaT+p8DkZagtUJo7mLw/8licTrt3PFF/1VtjqoJ1 4Wclm+u0/w0VOpb5wZp0dn5LTzqkt6ZshipCacepjNJD1t3sHaYfaI8W0T5T9Eqfla dqpF/i1Xgqy6Al4bT8utXGkVRrZx6gdbQr2eLfRaRxR00fOiN4l8JqqJ+CZuPe46KL 2ELLR1x1/KyxQ== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 28F70CE1163; Thu, 6 Mar 2025 12:00:02 -0800 (PST) Date: Thu, 6 Mar 2025 12:00:02 -0800 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, vschneid@redhat.com, neeraj.upadhyay@kernel.org, frederic@kernel.org, kernel-team@meta.com Subject: [PATCH] stop-machine: Add comment for rcu_momentary_eqs() Message-ID: <9d3f4116-db64-43fb-85f1-0b939038206e@paulmck-laptop> Reply-To: paulmck@kernel.org Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a comment to explain the purpose of the rcu_momentary_eqs() call from multi_cpu_stop(), which is to suppress false-positive RCU CPU stall warnings. Reported-by: Thomas Gleixner Link: https://lore.kernel.org/all/87wmeuanti.ffs@tglx/ Signed-off-by: Paul E. McKenney Cc: Valentin Schneider Cc: Neeraj Upadhyay Cc: Frederic Weisbecker --- stop_machine.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 8896d844d738f..5d2d0562115b3 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -250,6 +250,7 @@ static int multi_cpu_stop(void *data) * be detected and reported on their side. */ touch_nmi_watchdog(); + /* Also suppress RCU CPU stall warnings. */ rcu_momentary_eqs(); } } while (curstate !=3D MULTI_STOP_EXIT);