From mboxrd@z Thu Jan 1 00:00:00 1970 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 DFE933E5568 for ; Mon, 4 May 2026 19:07:16 +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=1777921636; cv=none; b=SRo6BbN58xdHn3+l6WPIUk3wJN5gz1cToRIAqXLiC9pXHxyzGqvvZUTBTnkH3tdmQ+QT4OYQzwg1zaFX3BjXKTbzO1LmZXfPNc7wajC7Y1b5xE58NOrmTx4HE/2wcdzbqqg5EgDqLN5i5GruCWysyVgKnr1pZSbtwjxyYwGg6Sg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777921636; c=relaxed/simple; bh=wrcvcDQM9qzv6zoJI10nTJQbS729ZfeVfAiP8RdSGe8=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=smgsyS4U955Zu3wGelMj2Q1qinNmlAWL1NLw/F+z1evYJDcE7tVCmtfVwzBnwzxpo+qVOcmD4UU7+hecpvA5uqj7mt2gfeod/ogvBmy7uiU5m6rqkaqr3Z/HXy67vsIj9A4nEqBtxlgql14VQJF9oic8sZCDpDkySNKrS1MZhTc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CWGvEuSr; 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="CWGvEuSr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E694FC2BCF4; Mon, 4 May 2026 19:07:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777921636; bh=wrcvcDQM9qzv6zoJI10nTJQbS729ZfeVfAiP8RdSGe8=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date:From; b=CWGvEuSratycJ+DQ6uUIBz+enfhuQXpXG91/KLQ3ht4eIphd/4KLDExk6FC3QE7ZR 3xu5kQ3LEsPleAEwVvAbTv6s1usXN/0lCY4YQmbk3LXh4egSkzwXo56q+YZiexiDDj 2PmXUg0o32Tc5LjpnINZYEXuo99CgX4vWuYxfKQE+xmrGLRr0TlPZqaHZKAGClYe91 VBk8X+D+8C749TMbGV7K2UT2UkCC/GnIssW2OYHk6FX1hliPmRpiPhkkawsd/Zi8q6 yVXBFF/UY1ttPyMBJkcwMJI+BB7XXVK4Qp5WA62+ltf9gkJJ4AQJPiWKkfTjYxUE3o RAr29fIP78ugw== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 2/2] sched_ext: Fix exit_cpu accuracy for lockup paths Reply-To: sashiko@lists.linux.dev To: "Cheng-Yang Chou" Cc: sched-ext@lists.linux.dev In-Reply-To: <20260504161543.674488-3-yphbchou0911@gmail.com> References: <20260504161543.674488-3-yphbchou0911@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 04 May 2026 19:07:14 +0000 Message-Id: <20260504190715.E694FC2BCF4@smtp.kernel.org> Precedence: bulk X-Mailing-List: sched-ext@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Medium] synchronize_rcu_expedited_wait() incorrectly passes the detector= CPU instead of the stalled CPU or -1 to panic_on_rcu_stall(). -- commit be51680372265a1376da290cd206c8c990bc5343 Author: Cheng-Yang Chou sched_ext: Fix exit_cpu accuracy for lockup paths This commit updates lockup detection paths to pass the actually stalled CPU, rather than the CPU executing the detection code, to handle_lockup(). It modifies scx_hardlockup_irq_workfn(), scx_rcu_cpu_stall(), and panic_on_rcu_stall() to accept the stalled CPU as an argument. [ ... ] > diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h > index 82cada459e5d0..fa83e273a6487 100644 > --- a/kernel/rcu/tree_exp.h > +++ b/kernel/rcu/tree_exp.h > @@ -675,7 +675,7 @@ static void synchronize_rcu_expedited_wait(void) > =20 > nbcon_cpu_emergency_exit(); > =20 > - panic_on_rcu_stall(); > + panic_on_rcu_stall(raw_smp_processor_id()); The commit message states that recording the detector CPU rather than the stalled CPU is wrong. However, in synchronize_rcu_expedited_wait(), it appears raw_smp_processor_= id() represents the CPU waiting for the expedited grace period (the detector CPU= ), not necessarily the CPU that is stalled. Does passing raw_smp_processor_id() here contradict the patch's stated goal by incorrectly blaming the detecting CPU? If identifying a specific stalled CPU is difficult in this path, would it be more appropriate to pass -1 to indicate no specific CPU is targeted? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260504161543.6744= 88-1-yphbchou0911@gmail.com?part=3D2