From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 E0519313526; Mon, 22 Sep 2025 18:08:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758564517; cv=none; b=VdZS9yynR3YDebSCTzh51w3f6xHnOcL5Cie6yCMazCYZF4tklBeSDQgDdzq9uG+dOtO4l+IW0Oih2b0VTvVh1tHOYViJU5gr2kRibG2ve0+SERdQ/LIh0R54TEjKhUA4EsN/EpXfTRoixH53qAHsX6kYbEYi1qGvFU0aOP6NKw8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758564517; c=relaxed/simple; bh=tKJT6in7ur7nDpwsOw7KRNMi6M5Kfufpw8RxWEQB3gw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ub/OtjqASEajjnQWhx6TfnSsccV/TFUjXEurxeLp9rDEQrOSzw3g8Ed21Nxu9cHYivKCf8/x2vuMOEusvAwynxbDaFblzOsZ7sjRduOBjU4Z4JxZSZTnRMlMXCoXhSxy0aftqeR12TI6DI0+zGyP8x1FSeU78W6o8BL9pEFIBPU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=JSX3p04D; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="JSX3p04D" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=jQtZMBG55C+hVDGJ8duLOpG289A0c5o5Wr/sU5kj90Q=; b=JSX3p04DHi9p3pN6jPTS1lw8t3 t75xjBNCz5FRbj9NFF4C/pi+LN3Y/djhaRl7yPhdImVPEge4SFFM1b7p6OJ1FCAbgvS+V+CjHm8Dw vWQAfu8z3avjmoqoE2zR6tNR+2+GcPz9RWvuNBUdBfyWrPIB6Db+pAqsuw/Ji3K8qpbYbN7k2vRh3 6LKjsmlh3ThsCfeyb/Li/zx3GMrUWxF7X+Tty4UIBkAXclq/Umzo9PVGn52ZTfZZ014H/WSkD4VYs hmNoGJK4p6doKz0gCy2sde4ToIA9zKXQvN5NZTHQnjFcfw8mk4Jh29aMTzAOyjTpOSIQUD1HPm3Gq d0kQivmg==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1v0kxk-0000000BDQU-3Sv6; Mon, 22 Sep 2025 18:08:32 +0000 Date: Mon, 22 Sep 2025 11:08:32 -0700 From: Christoph Hellwig To: Peter Zijlstra Cc: Julian Sun , cgroups@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, akpm@linux-foundation.org, lance.yang@linux.dev, mhiramat@kernel.org, agruenba@redhat.com, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev Subject: Re: [PATCH 0/3] Suppress undesirable hung task warnings. Message-ID: References: <20250922094146.708272-1-sunjunchao@bytedance.com> <20250922132718.GB49638@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250922132718.GB49638@noisy.programming.kicks-ass.net> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Sep 22, 2025 at 03:27:18PM +0200, Peter Zijlstra wrote: > > Julian Sun (3): > > sched: Introduce a new flag PF_DONT_HUNG. > > writeback: Introduce wb_wait_for_completion_no_hung(). > > memcg: Don't trigger hung task when memcg is releasing. > > This is all quite terrible. I'm not at all sure why a task that is > genuinely not making progress and isn't killable should not be reported. The hung device detector is way to aggressive for very slow I/O. See blk_wait_io, which has been around for a long time to work around just that. Given that this series targets writeback I suspect it is about an overloaded device as well. > ---end quoted text---