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=-2.4 required=3.0 tests=DKIM_SIGNED, MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID,USER_AGENT_MUTT 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 92478C28CF6 for ; Thu, 26 Jul 2018 06:21:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4188420895 for ; Thu, 26 Jul 2018 06:21:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QDOJlF1d" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4188420895 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728619AbeGZHg3 (ORCPT ); Thu, 26 Jul 2018 03:36:29 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:46596 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726943AbeGZHg3 (ORCPT ); Thu, 26 Jul 2018 03:36:29 -0400 Received: by mail-pg1-f194.google.com with SMTP id p23-v6so471784pgv.13 for ; Wed, 25 Jul 2018 23:21:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=sEXKLVNBOKqjuIuJAKRq0v7zRYtuw5VcaU0Zx9zMpxM=; b=QDOJlF1dI447WLRI5isgoq/Z/yjObWKE+E9iuT/4CBwdhqYMT7f16cKYtggUzagXWo qaWrbBiO8lQIMtrua1EQjMasLY7g1prKo6zBkaFSmuzrs9H5n0MZlndUq+y58qhOqXzQ GZEcRhGNcIptte2aBgl8CLv8c6E6UUAd6AfX5ZFWSPSglOLIGH61iA6XBuf931ar0N8l LztrsMcQyJOWipCSoWtlSVF1wBgGPjzYNPcNRQEUaaXAj+IGIF3h7LFpAGokOaCbFAq2 m09wBbqeMYIFGKVVKT7JiRib1lp1F3IKBN1skhEfn2toTjdZE4/XXJMNJLXvENSNXXle ruDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=sEXKLVNBOKqjuIuJAKRq0v7zRYtuw5VcaU0Zx9zMpxM=; b=Ei8yBG05DuI6cTMj8wDqIIF84t7ihT5MTQp7Bx59F5weDxs6fIKVMb/RXXi40WPTQn Kk/AS2ut1DqJt5cp4SiYoQu1QFxpBTwsIWtK1NsXXphxRlZiBSGRlGdCfZy/a26XJzJZ HM2oAw5JBEHWCJ9fNEWPeyIjjyUTrXATR4qbo8Z5RXNblCvs22Ja+FPNqdb0uHoYmO4L vBiWGrB1MdkQJTgunhHP7LitnDERcsLQ9Xl+Rf8ltgxROxP+kmyy5xRVeE9rz/K1aIDD 8Ey47E7EE7hYAplxJMIeQlNtxD+yWTsviWxIscrqWOnwxb9NQFHMuJwRdkjEalS4MATy ZYRg== X-Gm-Message-State: AOUpUlGIe3n5RuSAZUm6jAEvJGFH0b0+JNc+xPFM6okX5ZpobVnWojJU b9m6Aw5cxtoQZ8wAIJ3UDYj9fzw0 X-Google-Smtp-Source: AAOMgpfZYDs53WBOTdAolDTSlHKxVKDY65N+6b3B5S+t3tfnYF7wGMcF5E/+TSLHE4S+Pd9IyspX5g== X-Received: by 2002:a63:6b86:: with SMTP id g128-v6mr697277pgc.344.1532586072139; Wed, 25 Jul 2018 23:21:12 -0700 (PDT) Received: from rodete-desktop-imager.corp.google.com ([2401:fa00:d:10:affa:813f:5380:6613]) by smtp.gmail.com with ESMTPSA id x2-v6sm1088627pfi.166.2018.07.25.23.21.08 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 25 Jul 2018 23:21:10 -0700 (PDT) Date: Thu, 26 Jul 2018 15:21:06 +0900 From: Minchan Kim To: Tino Lehnig Cc: ngupta@vflare.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky , Andrew Morton Subject: Re: Zram writeback feature unstable with heavy swap utilization - BUG: Bad page state in process... Message-ID: <20180726062106.GB221405@rodete-desktop-imager.corp.google.com> References: <0516ae2d-b0fd-92c5-aa92-112ba7bd32fc@contabo.de> <20180724010342.GA195675@rodete-desktop-imager.corp.google.com> <20180725132126.GA2893@rodete-laptop-imager.corp.google.com> <20180726020351.GA221405@rodete-desktop-imager.corp.google.com> <1684cefc-c920-d53c-8d2d-c32da213a045@contabo.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1684cefc-c920-d53c-8d2d-c32da213a045@contabo.de> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 26, 2018 at 08:10:41AM +0200, Tino Lehnig wrote: > Hi, > > On 07/26/2018 04:03 AM, Minchan Kim wrote: > > A thing I could imagine is > > [0bcac06f27d75, skip swapcache for swapin of synchronous device] > > It was merged into v4.15. Could you check it by bisecting? > > Thanks, I will check that. > > > > My operating system is a minimal install of Debian 9. I took the kernel > > > configuration from the default Debian kernel and built my own kernel with > > > "make oldconfig" leaving all settings at their defaults. The only thing I > > > changed in the configuration was enabling the zram writeback feature. > > > > You mean you changed host kernel configuration? > > > > > > > > All my tests were done on bare-metal hardware with Xeon processors and lots > > > of RAM. I encounter the bug quite quickly, but it still takes several GBs of > > > swap usage. Below is my /proc/meminfo with enough KVM instances running (3 > > > in my case) to trigger the bug on my test machine. > > > > Aha.. you did writeback feature into your bare-metal host machine and execute > > kvm with window images as a guest. So, PG_uptodate warning happens on host side, > > not guest? Right? > > Yes, I am only talking about the host kernel. Zram swap is set up on the > host. I just used Windows guests to fill up the host RAM and force it into > swap. > > > > I will also try to reproduce the problem on some different hardware next. > > Just to confirm, I was able to reproduce the problem on another machine > running Ubuntu 18.04 with the Ubuntu stock kernel (4.15) and no > modifications to the kernel configuration whatsoever. The host had 8 GB of That means you could reproduce it without writeback feature? If so, it would be more reasoanble to check [0bcac06f27d75, skip swapcache for swapin of synchronous device] > RAM, 32 GB of swap with zram and a 32 GB SSD as backing device. I had to > start only one Windows VM with "-m 32768" to trigger the bug. Thanks. I will try it later today.