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 F3A562CCDB; Mon, 3 Mar 2025 13:00:08 +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=1741006809; cv=none; b=cFLA8s4YK8YvIvP2r4UeD/Fe+idammlYOf6jd9VULuz1LGFBFYevNM9JBBC4feubOulfmI3h1PZRRC8tmBYaqquV6W43K6f+Ij5LCqn7KiYLADIr6twZ68P+jdsJKM3FBqve5BenjH/H2cp35wv4yf9k7Z+6BDVe9cTyuAehQRY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741006809; c=relaxed/simple; bh=7apc++eodbya1vbUNOU+RwOGlXlR756MQt8yqfopEe4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DdKNtvNnTEVCmeSi1mKY15rzkUyyKSmLahzHKKyN66waXy/GCHVBhd5/3jfS02ZCCMOwpAV/vCAf8XsnUkB+LAAGdmo9eWi4v21bM8A34bv9ZOtmPfBNdSVUuiCKIgQb85SZqzZN5IZG6FndelOJGEsDYyitQPhn9zZJYTvYIYI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Bi/zc1PB; 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="Bi/zc1PB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCA81C4CED6; Mon, 3 Mar 2025 13:00:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741006808; bh=7apc++eodbya1vbUNOU+RwOGlXlR756MQt8yqfopEe4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Bi/zc1PB/808CvRt6KvPxPgnhfFiJ/yA1/CYUoQhuY7dczSo7delI+3/qDHuEo7TB sROWAZ3Y87vgbx/A96buxMusKBGO2WxDe3zgu4SHdXterDbYNKJGGtcDQmHj1tvrUt ML2uo6Y/6/lcGx5Z+GEMyrTH67sq8tQEYYyfIqHffgqtn7RLLmJBv14vXKx/OdsgPO GWBz5yTgx4RAoiy0J1ROvTEUyVjneZ6wVppdffnnipRcuy0taz0ZRvqKJ2/hRqo30r tsgsI3e+ZZpThdIgGZmda1XLnH9yzE1w9HTcva4b2UQytD7o1xRS3OP7yj5KG+Q1Wk 9Ui8UAldwnkrQ== Date: Mon, 3 Mar 2025 14:00:02 +0100 From: Alexey Gladkov To: Oleg Nesterov Cc: "Sapkal, Swapnil" , Manfred Spraul , Linus Torvalds , Christian Brauner , David Howells , WangYuli , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, K Prateek Nayak , "Shenoy, Gautham Ranjal" , Neeraj.Upadhyay@amd.com Subject: Re: [PATCH] pipe_read: don't wake up the writer if the pipe is still full Message-ID: References: <20250102140715.GA7091@redhat.com> <20250224142329.GA19016@redhat.com> <20250225115736.GA18523@redhat.com> 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: <20250225115736.GA18523@redhat.com> On Tue, Feb 25, 2025 at 12:57:37PM +0100, Oleg Nesterov wrote: > On 02/24, Oleg Nesterov wrote: > > > > Just in case, did you use > > > > https://git.kernel.org/pub/scm/utils/rt-tests/rt-tests.git/tree/src/hackbench/hackbench.c > > > > ? > > Or did you use another version? > > Exactly what parameters did you use? > > If possible, please reproduce the hang again. How many threads/processes > sleeping in pipe_read() or pipe_write() do you see? (you can look at > /proc/$pid/stack). > > Please pick one sleeping writer, and do > > $ strace -p pidof_that_write > > this should wake this writer up. If a missed wakeup is the only problem, > hackbench should continue. > > The more info you can provide the better ;) I was also able to reproduce the hackbench hang with the parameters mentioned earlier (threads and processes) on the kernel from master. -- Rgrds, legion