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 Received: from picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 44763C433FE for ; Fri, 11 Nov 2022 08:38:48 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id 1B5B33CD51D for ; Fri, 11 Nov 2022 09:38:46 +0100 (CET) Received: from in-4.smtp.seeweb.it (in-4.smtp.seeweb.it [IPv6:2001:4b78:1:20::4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id 286753CAAE3 for ; Fri, 11 Nov 2022 01:48:39 +0100 (CET) Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-4.smtp.seeweb.it (Postfix) with ESMTPS id D576F10007EF for ; Fri, 11 Nov 2022 01:48:38 +0100 (CET) Received: by mail-pf1-x42e.google.com with SMTP id z26so3578221pff.1 for ; Thu, 10 Nov 2022 16:48:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=/gUNRy1qZIXrqUZUL7883/f/GJegibYfXZQZVngW38U=; b=VWZwrH2WTLZH7q/x1ZgpdvYSrGqwsN5f7i9ypcQ7UreI7sa/e03yNK6qv9VxqDlXP8 i04ZhlEljAEqFDY6vjaYs/QXE3J3167rQ2D69YQqoO8AcyVoep415lPw40kShPC8NBdV 9bzPkkL603xzDjwINJOebgWujA4I8bQIIWYOA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=/gUNRy1qZIXrqUZUL7883/f/GJegibYfXZQZVngW38U=; b=da0tqb6qUhsQCuUOW+J8zrllZM2R0A44kP9OY2dSIjJlH1W9I8K+1oyeePw0NEYAPN 0vYFHrUh5S/9JKA72Vfl8HlrLYx8vAEZINUBAWHrHZfRl/dg28Y4BrtAQx9D11ldd/5E Hih3k6Z0RI2UguEv74V3meI+tXg3tfam30uCMz3z9Yr9vV+GYZHHMZ5MXBSQ7ba2mCbF DM3PSLQNz9wSifumfjSJNcNmVh9YJxlVTgVCDiuAODCMgR/O8lQ/yaXB888yS+zChLEM UPCcGp4T/gPabStu/OtrgY/gYTD4KJ0FeqPwh649YMt89Xzo98oV4qzUx5tb19hkNLsp v2oQ== X-Gm-Message-State: ACrzQf03RT4SZiUIKxo3P8zgbBI17oCkQYgpvso23Tq0UjqvRzcpl+pE G6byK0Zrz2LzXqS6bmxrSQBZOA== X-Google-Smtp-Source: AMsMyM7sIWgS/0TfYwBT7X/dzMu66eUOL/4N1tpn2UCyic5dZmo1cMUhDUlzUKuzT+rqzDYvi7knxQ== X-Received: by 2002:a63:fc14:0:b0:43c:2e57:97df with SMTP id j20-20020a63fc14000000b0043c2e5797dfmr3852168pgi.189.1668127717205; Thu, 10 Nov 2022 16:48:37 -0800 (PST) Received: from google.com ([240f:75:7537:3187:8d55:c60d:579d:741c]) by smtp.gmail.com with ESMTPSA id g6-20020a632006000000b004388ba7e5a9sm221005pgg.49.2022.11.10.16.48.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Nov 2022 16:48:36 -0800 (PST) Date: Fri, 11 Nov 2022 09:48:31 +0900 From: Sergey Senozhatsky To: Martin Doucha Message-ID: References: <20221107191136.18048-1-pvorel@suse.cz> <3ac740c0-954b-5e68-b413-0adc7bc5a2b5@suse.cz> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <3ac740c0-954b-5e68-b413-0adc7bc5a2b5@suse.cz> X-Virus-Scanned: clamav-milter 0.102.4 at in-4.smtp.seeweb.it X-Virus-Status: Clean X-Mailman-Approved-At: Fri, 11 Nov 2022 09:38:05 +0100 Subject: Re: [LTP] [PATCH 0/1] Possible bug in zram on ppc64le on vfat X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jens Axboe , OGAWA Hirofumi , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Minchan Kim , Nitin Gupta , linux-kselftest@vger.kernel.org, Sergey Senozhatsky , ltp@lists.linux.it Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" On (22/11/10 15:29), Martin Doucha wrote: > New version of LTP test zram01 found a sysfile issue with zram devices > mounted using VFAT filesystem. When when all available space is filled, e.g. > by `dd if=/dev/zero of=/mnt/zram0/file`, the corresponding sysfile > /sys/block/zram0/mm_stat will report that the compressed data size on the > device is 0 and total memory usage is also 0. LTP test zram01 uses these > values to calculate compression ratio, which results in division by zero. > > The issue is specific to PPC64LE architecture and the VFAT filesystem. No > other tested filesystem has this issue and I could not reproduce it on other > archs (s390 not tested). The issue appears randomly about every 3 test runs > on SLE-15SP2 and 15SP3 (kernel 5.3). It appears less frequently on SLE-12SP5 > (kernel 4.12). Other SLE version were not tested with the new test version > yet. The previous version of the test did not check the VFAT filesystem on > zram devices. Whoooaa... > I've tried to debug the issue and collected some interesting data (all > values come from zram device with 25M size limit and zstd compression > algorithm): > - mm_stat values are correct after mkfs.vfat: > 65536 220 65536 26214400 65536 0 0 0 > > - mm_stat values stay correct after mount: > 65536 220 65536 26214400 65536 0 0 0 > > - the bug is triggered by filling the filesystem to capacity (using dd): > 4194304 0 0 26214400 327680 64 0 0 Can you try using /dev/urandom for dd, not /dev/zero? Do you still see zeroes in sysfs output or some random values? -- Mailing list info: https://lists.linux.it/listinfo/ltp