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=-7.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 7D39BC2B9F4 for ; Thu, 17 Jun 2021 15:37:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60235610CA for ; Thu, 17 Jun 2021 15:37:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233332AbhFQPkG (ORCPT ); Thu, 17 Jun 2021 11:40:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231661AbhFQPkC (ORCPT ); Thu, 17 Jun 2021 11:40:02 -0400 Received: from mail-ed1-x52c.google.com (mail-ed1-x52c.google.com [IPv6:2a00:1450:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43452C061574 for ; Thu, 17 Jun 2021 08:37:54 -0700 (PDT) Received: by mail-ed1-x52c.google.com with SMTP id w21so4648987edv.3 for ; Thu, 17 Jun 2021 08:37:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rasmusvillemoes.dk; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=YT85gP+YFDJ5ychGyvNL82kun+NGGvSQi4A8qTsyAT8=; b=d2GK9t3nL2nAfTcf7lqXjd31fD7Hz5xzxIAJtdTuGMg15qEOCzDgflXnVUQN8grvuM EeDaBMTzUJ5xRvELBxH/CNS4pCSwowu44jiHt3qIjmlgS1IMEZ8ZQIhPGE+4zoWIiZC3 gnXozEqWX4Im4+7CVdSM9IFtkfATJIFunDZyk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=YT85gP+YFDJ5ychGyvNL82kun+NGGvSQi4A8qTsyAT8=; b=g/hGd6C9FuE+UUf9JlACE6HZYBVgrLPdGpgyqdZnrE0sl301fp0jvF1C9d7RRGPfZc F5wWGusyUYpQP0cEE2xH41oEWK81QvOKH+6J0Dqg6/VI8g3VH0Yct+WJWgcV+dpp5kme MIB5LHH6Pm4pIs3ZtHkpPWLyXXfmHF51TDdCgyDImnxANOa8NvaF2r29AxlCXS6twG1Y M+swumA3hHJtMiT3YeXJt4nuhEfJNDVdwexQz6PoxSj5qbK1dfQlk74vGfT0df16RlL+ xNjMqtVu73R8wkk7zOcaTYvwhlLCPw8K9E1wRFztWYCEamGZPf1yasUKc24TyI3wPAph 2rLg== X-Gm-Message-State: AOAM5313v8kL6cz3/who0svI/BsU/2fPdLz1r87Fkqm7g7+Eig1WPJcy TtkLgUvaJ2rGeCHTtwQJeMPcdw== X-Google-Smtp-Source: ABdhPJx5RzRT+L7RIRvsl9usmDDDf/qtiyT+vCzmybNW0ErUVakZubdtURjpJlM3bBjtB8KFQFyMAA== X-Received: by 2002:aa7:c705:: with SMTP id i5mr7526454edq.222.1623944272883; Thu, 17 Jun 2021 08:37:52 -0700 (PDT) Received: from [192.168.1.149] ([80.208.64.110]) by smtp.gmail.com with ESMTPSA id j24sm4538603edv.48.2021.06.17.08.37.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 17 Jun 2021 08:37:52 -0700 (PDT) Subject: Re: Linux 5.13-rc6 regression to 5.12.x: kernel OOM and panic during kernel boot in low memory Xen VM's (256MB assigned memory). To: Linus Torvalds , Sander Eikelenboom Cc: linux-kernel , "xen-devel@lists.xenproject.org" References: From: Rasmus Villemoes Message-ID: <9108c22e-3521-9e24-6124-7776d947b788@rasmusvillemoes.dk> Date: Thu, 17 Jun 2021 17:37:51 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17/06/2021 17.01, Linus Torvalds wrote: > On Thu, Jun 17, 2021 at 2:26 AM Sander Eikelenboom wrote: >> >> I just tried to upgrade and test the linux kernel going from the 5.12 kernel series to 5.13-rc6 on my homeserver with Xen, but ran in some trouble. >> >> Some VM's boot fine (with more than 256MB memory assigned), but the smaller (memory wise) PVH ones crash during kernel boot due to OOM. >> Booting VM's with 5.12(.9) kernel still works fine, also when dom0 is running 5.13-rc6 (but it has more memory assigned, so that is not unexpected). > > Adding Rasmus to the cc, because this looks kind of like the async > roofs population thing that caused some other oom issues too. Yes, that looks like the same issue. > Rasmus? Original report here: > > https://lore.kernel.org/lkml/ee8bf04c-6e55-1d9b-7bdb-25e6108e8e1e@eikelenboom.it/ > > I do find it odd that we'd be running out of memory so early.. Indeed. It would be nice to know if these also reproduce with initramfs_async=0 on the command line. But what is even more curious is that in the other report (https://lore.kernel.org/lkml/20210607144419.GA23706@xsang-OptiPlex-9020/), it seemed to trigger with _more_ memory - though I may be misreading what Oliver was telling me: > please be noted that we use 'vmalloc=512M' for both parent and this commit. > since it's ok on parent but oom on this commit, we want to send this report > to show the potential problem of the commit on some cases. > > we also tested by changing to use 'vmalloc=128M', it will succeed. Those tests were done in a VM with 16G memory, and then he also wrote > we also tried to follow exactly above steps to test on > some local machine (8G memory), but cannot reproduce. Are there some special rules for what memory pools PID1 versus the kworker threads can dip into? Side note: I also had a ppc64 report with different symptoms (the initramfs was corrupted), but that turned out to also reproduce with e7cb072eb98 reverted, so that is likely unrelated. But just FTR that thread is here: https://lore.kernel.org/lkml/CA+QYu4qxf2CYe2gC6EYnOHXPKS-+cEXL=MnUvqRFaN7W1i6ahQ@mail.gmail.com/ Rasmus