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 DD2461A6811; Mon, 2 Mar 2026 21:56:41 +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=1772488601; cv=none; b=IbuBLtQZAD/R3v8rsfhQWBEdgsZASkdTzJJ5FkafMeLBoTbtAYPt1Wcb12Df1PVnrpTZQVpo7jlO64t+q2BkIqYnL30RoaF4BhlKGlhJVlHN49rrjUSb3y3bwMuxOGt+z4mdhD+Vj3aShg67dkAs1Hd1dLYhoF4xAEhVRhqrzAw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772488601; c=relaxed/simple; bh=UE2MVOl289ObbgK0+40wIBB2si4+wyFn2M+IMfT4G3U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NtZFIlRdeWVZlpjnYFMvx2IohTurDJ6n2JJvQDGVTfZ/MhBk1CpGoj+pqNNgX8wALSqdo71ZE8wYVg4oZ5yhQbxLzcFFrHmC0wxBSHIx+GpVAoYZoOXdla62yPNe8tLzmyDv83dIjXbWhKho86heoIW8d5yPwgPCt3uF8ydgRXg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kRvxKUmq; 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="kRvxKUmq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56991C19423; Mon, 2 Mar 2026 21:56:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772488601; bh=UE2MVOl289ObbgK0+40wIBB2si4+wyFn2M+IMfT4G3U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kRvxKUmquy0pQpYUBrRNOmty6cnaQzc/xUveZw3X4JhzmeQZNQo2CUgli3772ZeIS 8k+sESJBNU7mB/f3N1RyAdCsVBzN7Yk23kuj73wG5PRN0/s3beVW8l0KxWHqv5kRm5 rahmkQTelJulzchyJtogFpRArYc9yoxhCVSwFLW5tC8GLZoJl1kgUcCrXkJ1Sy6HLm wt6LSi77uYEK2X9e2BipShejoI0CdxWAWY33kc6crgBtGHc37HsZcePeIyeODpS8aP Pm5+icuMZDfMBh3czHAlwlE7opHaq3vDYrqrtFR3WPOepGA2DAV2jYBV7UM3crsUTg KASxeDsHqvpgQ== Date: Mon, 2 Mar 2026 11:56:40 -1000 From: Tejun Heo To: Sebastian Andrzej Siewior Cc: linux-rt-devel@lists.linux.dev, cgroups@vger.kernel.org, Johannes Weiner , Michal =?iso-8859-1?Q?Koutn=FD?= , Clark Williams , Steven Rostedt , Bert Karwatzki Subject: Re: [PATCH] cgroup: Don't expose dead tasks in cgroup Message-ID: References: <20260302120738.6KkDipsR@linutronix.de> Precedence: bulk X-Mailing-List: linux-rt-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260302120738.6KkDipsR@linutronix.de> Hello, Seb. On Mon, Mar 02, 2026 at 01:07:38PM +0100, Sebastian Andrzej Siewior wrote: > Tejun, with this change, would it be okay to > - replace the irq-work with kworker? With this change it should address > your concern regarding "run in definite time" as mentioned in [0]. So > it might be significantly delayed but it shouldn't be visible. > This would lift the restriction that a irq-work needs to run on this > CPU and the kworker could run on any CPU. Yeah, that's fine. > - would it be okay to treat RT and !RT equally here (and do this delayed > cgroup_task_dead() in both cases) I don't see why we'd bounce on !RT. Are there any benefits? > @@ -5283,6 +5283,11 @@ static void *cgroup_procs_start(struct seq_file *s, loff_t *pos) > > static int cgroup_procs_show(struct seq_file *s, void *v) > { > + struct task_struct *tsk = v; > + > + if (READ_ONCE(tsk->__state) & TASK_DEAD) > + return 0; Does this actually close the window for systemd through operation ordering or does it just reduce the race window? Thanks. -- tejun