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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 79C87C33CB1 for ; Wed, 15 Jan 2020 08:43:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4DD902077B for ; Wed, 15 Jan 2020 08:43:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579077820; bh=vwpx7jmy/UsNz4oukcDm0Up8DtcbyNZm+J/hXoV3gb4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=wXBwAn/gPoI2rwmntvHvMXc1IpWgs1PVAFeLEXPNpULNdS4U/xwLV07HkFmKVWX2l QeLL5kIwH/RWRoX1uBgexloSD1cAvWsOFjblAoRuxSnGjblzfdMjeNapf3OOf1Gt/K dJQagVMVfvunma8xhAozbEjezABmlz9Z3bWZCQhk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729081AbgAOInj (ORCPT ); Wed, 15 Jan 2020 03:43:39 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:36263 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726472AbgAOInj (ORCPT ); Wed, 15 Jan 2020 03:43:39 -0500 Received: by mail-wr1-f65.google.com with SMTP id z3so14872847wru.3 for ; Wed, 15 Jan 2020 00:43:38 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=S/PNDUAlVVVtYjvRnMN304qOmVqAvWD8J5Xrr48hgz4=; b=ZR7bqr2lzCWXVFanap+oLk7W9SrOEm1sfsRPZq9dvLTHUHtUMQZbojiTUK5yo0I7vq qv+ycjJIM8g9ZyriLul+qpwPKny4ixXJq22RXkd3b6X7n1uXHAmQtAvQ4pkB4qlF2STb 0WjKvpnMGMbraSuLunoV1AcOII2Ej+HtUYFYwbfbk1rnVGLUue5zwjEsC5lSNfjzo0iK vmwY7r/+pV5q4/okh4gwDps6XzCApCiE/HF1dZw0mv/VR37xKdprRGejYiRQpXsHYJvC Pxe+bZcNwEr7wjMG60MBHFsyjdbgDXqT1JpjKnx91+SFPwsg47U8JjMCdDnxy16aAD1w OjVw== X-Gm-Message-State: APjAAAX0FGMklDhUv5LeTGd/dFd/yIhYmddVkSXJsi2QrfYXWeSBxglr NGZGNn/XEwVRN8M4UO4ODAQ= X-Google-Smtp-Source: APXvYqwGLRWTLB0nzAWAVz8G3S+ZGQ2cWW5Hfuwg70alRK5byH//hBg1tHkuoYxkj7wUIgg9q1sI3g== X-Received: by 2002:adf:d4ca:: with SMTP id w10mr28545870wrk.53.1579077817600; Wed, 15 Jan 2020 00:43:37 -0800 (PST) Received: from localhost (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id t8sm23840123wrp.69.2020.01.15.00.43.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Jan 2020 00:43:36 -0800 (PST) Date: Wed, 15 Jan 2020 09:43:36 +0100 From: Michal Hocko To: David Rientjes Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [patch] mm, oom: dump stack of victim when reaping failed Message-ID: <20200115084336.GW19428@dhcp22.suse.cz> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 14-01-20 15:20:04, David Rientjes wrote: > When a process cannot be oom reaped, for whatever reason, currently the > list of locks that are held is currently dumped to the kernel log. > > Much more interesting is the stack trace of the victim that cannot be > reaped. If the stack trace is dumped, we have the ability to find > related occurrences in the same kernel code and hopefully solve the > issue that is making it wedged. > > Dump the stack trace when a process fails to be oom reaped. Yes, this is really helpful. > Signed-off-by: David Rientjes Acked-by: Michal Hocko Thanks! > --- > mm/oom_kill.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -26,6 +26,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -620,6 +621,7 @@ static void oom_reap_task(struct task_struct *tsk) > > pr_info("oom_reaper: unable to reap pid:%d (%s)\n", > task_pid_nr(tsk), tsk->comm); > + sched_show_task(tsk); > debug_show_all_locks(); > > done: -- Michal Hocko SUSE Labs