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=-7.3 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 E3A05C4743C for ; Mon, 21 Jun 2021 17:06:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C96FC60FDB for ; Mon, 21 Jun 2021 17:06:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231336AbhFURIe (ORCPT ); Mon, 21 Jun 2021 13:08:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37228 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231286AbhFURIS (ORCPT ); Mon, 21 Jun 2021 13:08:18 -0400 Received: from mail-ej1-x630.google.com (mail-ej1-x630.google.com [IPv6:2a00:1450:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0AB59C0599EB for ; Mon, 21 Jun 2021 09:54:03 -0700 (PDT) Received: by mail-ej1-x630.google.com with SMTP id hq39so2894254ejc.5 for ; Mon, 21 Jun 2021 09:54:02 -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=P2Td/+tIipAgfyxPjVHvnCAo9n1WaYveTmTAYM/j+jY=; b=diuj5gabJqISgVVxx3Akhkd9RYmJFByRkUBchT88Z00CkuGWojs+VGfxVUt18Ow1NT iIs9CPaqGh7r/1KD5cILlcpveOUj3CJF4M7DbQqERFA9+ywOFCmKxKF8X0t8+AlKR+tN jXwgDjJn9NupBFYxyzDNQyDRkmzMZohSurPoY= 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=P2Td/+tIipAgfyxPjVHvnCAo9n1WaYveTmTAYM/j+jY=; b=qgX3Hjc683YSC/3tiw/moJUdw64FXOFZSngD8xwGW8d/mahHe2pCEBqr6pwu3rzELC KhgCxngHHiQKlp8V+w9u9oOXkkpXG/TdJIkxFxQ1zHKfk11DQmBM1jd4Y5+BN4WlQ31P ypakDBuHwFu9q1sxXquFs5pMJAb0Xd5vTBSkRfTDhlg0qbeYm2lITsjJpWjzXtXEwLpV SG/cXtm8fG+sbRyUnkF9mEvzzyavjEq313AQZR8WjDcUA+bnEBpFK3S58Go+jX3tDNMM 2e1H1pcy2k943qfpADDSiaU7Zz6csw8fOk3KIV3AAAVPYi9ZL2jZOTyERnaxd+g79IHn gLSA== X-Gm-Message-State: AOAM532gF12gFuTLOKVoVutIE2InLlkkZwTlGdsxIRNIz/3CrNgoJ16b /llp5dri3omp3vG/m+1TY42rRg== X-Google-Smtp-Source: ABdhPJxjYawB6DJpcIRc0YMX54xgWCzAW7ksE8qOaz7mcYqVsYntvbdMZwPqOAEECmQCM421IbYweQ== X-Received: by 2002:a17:906:264c:: with SMTP id i12mr25567215ejc.101.1624294441554; Mon, 21 Jun 2021 09:54:01 -0700 (PDT) Received: from [192.168.1.149] ([80.208.64.110]) by smtp.gmail.com with ESMTPSA id f14sm313127edd.69.2021.06.21.09.54.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 21 Jun 2021 09:54:01 -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: Sander Eikelenboom , Linus Torvalds , Juergen Gross Cc: linux-kernel , "xen-devel@lists.xenproject.org" , kernel test robot References: <9108c22e-3521-9e24-6124-7776d947b788@rasmusvillemoes.dk> <0b12f27b-1109-b621-c969-10814b2c1c2f@eikelenboom.it> <7338064f-10b6-545d-bc6c-843d04aafe28@eikelenboom.it> From: Rasmus Villemoes Message-ID: Date: Mon, 21 Jun 2021 18:54:00 +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 18/06/2021 03.06, Sander Eikelenboom wrote: > On 17/06/2021 21:39, Sander Eikelenboom wrote: > > OK, done some experimentation and it seems with 256M assigned to the VM > it was almost at the edge of OOM with the 5.12 kernel as well in the > config I am using it. > With v5.12 when I assign 240M it boots, with 230M it doesn't. With 5.13 > the tipping point seems to be around 265M and 270M, so my config was > already quite close to the edge. > > The "direct kernel boot" feature I'm using just seems somewhat memory > hungry, but using another compression algorithm for the kernel and > initramfs already helped in my case. > > So sorry for the noise, clearly user-error. Hm, perhaps, but I'm still a bit nervous about that report from Oliver Sang/kernel test robot, which was for a VM equipped with 16G of memory. But despite quite a few attempts, I haven't been able to reproduce that locally, so unfortunately I have no idea what's going on. Rasmus