From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1CFFDC433F5 for ; Mon, 2 May 2022 13:36:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243514AbiEBNkI (ORCPT ); Mon, 2 May 2022 09:40:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1385362AbiEBNkF (ORCPT ); Mon, 2 May 2022 09:40:05 -0400 Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7851BDEC4; Mon, 2 May 2022 06:36:30 -0700 (PDT) Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id B20D75C00F3; Mon, 2 May 2022 09:36:29 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Mon, 02 May 2022 09:36:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=living180.net; h=cc:cc:content-transfer-encoding:content-type:date:date:from :from:in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to; s=fm2; t=1651498589; x= 1651584989; bh=DKuJbHbyPUqgLeOliLIbXn1AoO2Mdbl5+P4gRT3Ay2E=; b=D mpGN6XA6cMKSi58bz3l8aZ6f0nZszYbA57byZEbN4UOYQ6UwC9zY1CN0M7rLG9Rp q0Jk6futlLfwjyvo3EhDLr0YzYoW2y5Mo9l1zzF100c/iGKBXxRKEcsMp8nsrEei 3EMHXn1AkMu8JH0aySNvRhy48fGYw4/yDwsUE6AucL3JdUaGwUAI4xAB6Sdw56mn LzfRX0yF9BjT/eBfDZDj35CKGPb69j00NAweMEIu8VoDtzb6dE2+2hrcQ8sOCE/Q R3sFogjT/PIGWHMZMeSM78V/pN1t/scgdt4MoyegXQLZ6xNsp0pzHFNqlB8zxnxy OKg5iQjQIXNIztZdFhsYg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; t=1651498589; x=1651584989; bh=DKuJbHbyPUqgL eOliLIbXn1AoO2Mdbl5+P4gRT3Ay2E=; b=HCNoHfoxXu5Wonbjc0N2bAf8Zbggb kG4mENbrXQA6sPgYaiyfUvA+ky2FYQb8v3o1a7IrfJmr6SAKXaZixnVRuPpFTvR4 HjiYNIH2YcyILGa4KlQFggRSCRfMEN86oNY9/bgnc2HZ3UMwM7wRox01lQddOoVp QOfvxlbIM/zvGepMNdJntQygbEhiDVQ4K/4Tav/0xclLRq0W6rYpTsLCOCEyfdmp brVXOfoyxYZc57oONlnwsi6mvFFrkJG9JSQcRzL61fILXC/UlxjH8w+Tj9RdnmzY VqBxhey0BPevrDSlxcaVqwE7xXtrioIX2lJ/ifpbnF/+SrjN8L1MS9RgQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvfedrvdehgdeigecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefkffggfgfuvfevfhfhjggtgfesthekredttdefjeenucfhrhhomhepffgrnhhi vghlucfjrghrughinhhguceoughhrghrughinhhgsehlihhvihhnghdukedtrdhnvghtqe enucggtffrrghtthgvrhhnpeelkeehgeeffeefvdfhffdvteettdejteeutdfgvdduieef leefieegudfhjefhjeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrih hlfhhrohhmpeguhhgrrhguihhngheslhhivhhinhhgudektddrnhgvth X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 2 May 2022 09:36:28 -0400 (EDT) Message-ID: Date: Mon, 2 May 2022 16:36:25 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [REGRESSION] lxc-stop hang on 5.17.x kernels Content-Language: en-US To: Jens Axboe , Pavel Begunkov Cc: regressions@lists.linux.dev, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org References: <7925e262-e0d4-6791-e43b-d37e9d693414@living180.net> <6ad38ecc-b2a9-f0e9-f7c7-f312a2763f97@kernel.dk> From: Daniel Harding In-Reply-To: <6ad38ecc-b2a9-f0e9-f7c7-f312a2763f97@kernel.dk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 5/2/22 16:26, Jens Axboe wrote: > On 5/2/22 7:17 AM, Daniel Harding wrote: >> I use lxc-4.0.12 on Gentoo, built with io-uring support >> (--enable-liburing), targeting liburing-2.1. My kernel config is a >> very lightly modified version of Fedora's generic kernel config. After >> moving from the 5.16.x series to the 5.17.x kernel series, I started >> noticed frequent hangs in lxc-stop. It doesn't happen 100% of the >> time, but definitely more than 50% of the time. Bisecting narrowed >> down the issue to commit aa43477b040251f451db0d844073ac00a8ab66ee: >> io_uring: poll rework. Testing indicates the problem is still present >> in 5.18-rc5. Unfortunately I do not have the expertise with the >> codebases of either lxc or io-uring to try to debug the problem >> further on my own, but I can easily apply patches to any of the >> involved components (lxc, liburing, kernel) and rebuild for testing or >> validation. I am also happy to provide any further information that >> would be helpful with reproducing or debugging the problem. > Do you have a recipe to reproduce the hang? That would make it > significantly easier to figure out. I can reproduce it with just the following:     sudo lxc-create --n lxc-test --template download --bdev dir --dir /var/lib/lxc/lxc-test/rootfs -- -d ubuntu -r bionic -a amd64     sudo lxc-start -n lxc-test     sudo lxc-stop -n lxc-test The lxc-stop command never exits and the container continues running.  If that isn't sufficient to reproduce, please let me know. -- Regards, Daniel Harding