From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 869214718C7; Thu, 10 Sep 2026 21:40:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789076433; cv=none; b=eW2lXgRTr1/kAR/wJktGEb0iUIKF7DM9QP2K4sv86CupO3s4lz6DMIkxZajZh0lpLJGnIv0Xfz89c2NdhEnwEp1YhlAlZ4T//IiXEMFHT1taUmhthLxeMv0un0KSzGec0Fvp07BK2vh996XAvOj5BzowW3avoUMhFvE/5ecUtlU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789076433; c=relaxed/simple; bh=hQ92hRM85W2yQ4BsOOsArTW4MSVuY99ohn7KXkLPlQs=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References; b=XTg/znVy+H8/yHEptNqNvC9riXSRc4KqSNnPqZgcQ2TK90QyoVEku0b/EpTHl3aVN9U+eyVRoIVUKbbdqN/OD+6iScbRuFXYWphXYR/mtyMOJ1PMcUjrzYBlnzysYK51gyQVDEOR9dLQjpNhf+qOo2m/Cq/nlN/tQgx5kcOjyaw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aR3Mr/YQ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aR3Mr/YQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB8C71F000FF; Thu, 10 Sep 2026 21:40:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789076432; bh=iZOPSHl/wWbjfK2g/VfyZhH7RTOp8SRODGAYWEmztYI=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=aR3Mr/YQkjpmCGJLy5mnEnbsh+mzpkQrncDf3YPfu24KGfjcrPT0bBV27NBZCUWh2 XqN5S6kbHT+wMOF47qEZO0kectBfYxfwhtwsk1Ywwszlt1tphCyg3blWlSRrL5/CoZ AuIUxlggVX9npA4JVIZiknqxEJz1gfHAudNelI+9FGYTyvbnY0T7zteUPRpw0ID7cS zve7ha7SYrGeadWG6XwNMB+i/FNWXaf1uKGlU5HljLwmVT3eaSaTUaaM6pQS7ClQGZ VeUrTlLIkjBrLYfwuaQCBCXwFkVcZMajeJBeNkl3JSh7ACHJZNcvLUa12Ua4c3fVIQ 9yOgCUCtJJUxA== Date: Thu, 10 Sep 2026 11:40:31 -1000 Message-ID: From: Tejun Heo To: Qiurong Fang Cc: sched-ext@lists.linux.dev, David Vernet , Andrea Righi , Changwoo Min , Emil Tsalapatis , linux-kernel@vger.kernel.org, tj@kernel.org Subject: Re: [PATCH] sched_ext: Close the pre-enable ops error claim window In-Reply-To: <20260910084533.2420199-1-fangqiurong@kylinos.cn> References: <20260910084533.2420199-1-fangqiurong@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Hello, Qiurong. On Thu, Sep 10, 2026 at 04:45:33PM +0800, Qiurong Fang wrote: > + if (scx_tryset_enable_state(SCX_DISABLED, SCX_DISABLING)) > + goto done; > + break; Please drop this hunk. Once SCX_ENABLING precedes ops->priv publication, scx_tryset_enable_state() cannot fail here. > + if (!scx_tryset_enable_state(SCX_ENABLING, SCX_DISABLED)) { > + pr_warn("sched_ext: enable raced with a state transition, aborting\n"); > + ret = -EBUSY; This failure path is also unreachable. The state was checked as SCX_DISABLED under scx_enable_mutex, and no disable can start before publication. Please move the existing transition and retain the reset on allocation failure. Thanks. -- tejun