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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7AE2ECA9EA0 for ; Fri, 25 Oct 2019 11:46:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 46113206DD for ; Fri, 25 Oct 2019 11:46:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 46113206DD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D13256B0003; Fri, 25 Oct 2019 07:46:36 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C9BE66B0006; Fri, 25 Oct 2019 07:46:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B8A216B0007; Fri, 25 Oct 2019 07:46:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0057.hostedemail.com [216.40.44.57]) by kanga.kvack.org (Postfix) with ESMTP id 8D5BE6B0003 for ; Fri, 25 Oct 2019 07:46:36 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 2B94D482D for ; Fri, 25 Oct 2019 11:46:36 +0000 (UTC) X-FDA: 76082129592.09.cakes26_90ea74a85e72e X-HE-Tag: cakes26_90ea74a85e72e X-Filterd-Recvd-Size: 4193 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Fri, 25 Oct 2019 11:46:35 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 570B6B454; Fri, 25 Oct 2019 11:46:34 +0000 (UTC) Date: Fri, 25 Oct 2019 13:46:33 +0200 From: Michal Hocko To: snazy@snazy.de Cc: Randy Dunlap , linux-kernel@vger.kernel.org, Linux MM , Andrew Morton , "Potyra, Stefan" Subject: Re: mlockall(MCL_CURRENT) blocking infinitely Message-ID: <20191025114633.GE17610@dhcp22.suse.cz> References: <4576b336-66e6-e2bb-cd6a-51300ed74ab8@snazy.de> <20191025092143.GE658@dhcp22.suse.cz> <70393308155182714dcb7485fdd6025c1fa59421.camel@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <70393308155182714dcb7485fdd6025c1fa59421.camel@gmx.de> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri 25-10-19 13:02:23, Robert Stupp wrote: > On Fri, 2019-10-25 at 11:21 +0200, Michal Hocko wrote: > > On Thu 24-10-19 16:34:46, Randy Dunlap wrote: > > > [adding linux-mm + people] > > > > > > On 10/24/19 12:36 AM, Robert Stupp wrote: > > > > Hi guys, > > > > > > > > I've got an issue with `mlockall(MCL_CURRENT)` after upgrading > > > > Ubuntu 19.04 to 19.10 - i.e. kernel version change from 5.0.x to > > > > 5.3.x. > > > > > > > > The following simple program hangs forever with one CPU running > > > > at 100% (kernel): > > > > Can you capture everal snapshots of proc/$(pidof $YOURTASK)/stack > > while > > this is happening? > > Sure, > > Approach: > - one shell running > while true; do cat /proc/$(pidof test)/stack; done > - starting ./test in another shell + ctrl-c quite some times > > Vast majority of all ./test invocations return an empty 'stack' file. > Some tries, maybe 1 out of 20, returned these snapshots. > Was running 5.3.7 for this test. > > > [<0>] __handle_mm_fault+0x4c5/0x7a0 > [<0>] handle_mm_fault+0xca/0x1f0 > [<0>] __get_user_pages+0x230/0x770 > [<0>] populate_vma_page_range+0x74/0x80 > [<0>] __mm_populate+0xb1/0x150 > [<0>] __x64_sys_mlockall+0x11c/0x190 > [<0>] do_syscall_64+0x5a/0x130 > [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > [<0>] __handle_mm_fault+0x4c5/0x7a0 > [<0>] handle_mm_fault+0xca/0x1f0 > [<0>] __get_user_pages+0x230/0x770 > [<0>] populate_vma_page_range+0x74/0x80 > [<0>] __mm_populate+0xb1/0x150 > [<0>] __x64_sys_mlockall+0x11c/0x190 > [<0>] do_syscall_64+0x5a/0x130 > [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > [<0>] __handle_mm_fault+0x4c5/0x7a0 > [<0>] handle_mm_fault+0xca/0x1f0 > [<0>] __get_user_pages+0x230/0x770 > [<0>] populate_vma_page_range+0x74/0x80 > [<0>] __mm_populate+0xb1/0x150 > [<0>] __x64_sys_mlockall+0x11c/0x190 > [<0>] do_syscall_64+0x5a/0x130 > [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > [<0>] __do_fault+0x3c/0x130 > [<0>] do_fault+0x248/0x640 > [<0>] __handle_mm_fault+0x4c5/0x7a0 > [<0>] handle_mm_fault+0xca/0x1f0 > [<0>] __get_user_pages+0x230/0x770 > [<0>] populate_vma_page_range+0x74/0x80 > [<0>] __mm_populate+0xb1/0x150 > [<0>] __x64_sys_mlockall+0x11c/0x190 > [<0>] do_syscall_64+0x5a/0x130 > [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > This is expected. > // doubt this one is relevant > [<0>] __wake_up_common_lock+0x7c/0xc0 > [<0>] __wake_up_sync_key+0x1e/0x30 > [<0>] __wake_up_parent+0x26/0x30 > [<0>] do_notify_parent+0x1cc/0x280 > [<0>] do_exit+0x703/0xaf0 > [<0>] do_group_exit+0x47/0xb0 > [<0>] get_signal+0x165/0x880 > [<0>] do_signal+0x34/0x280 > [<0>] exit_to_usermode_loop+0xbf/0x160 > [<0>] do_syscall_64+0x10f/0x130 > [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Hmm, this means that the task has exited so how come there are other syscalls happening. Are you sure you are collecting stacks for the correct task? -- Michal Hocko SUSE Labs