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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A3BFC4332F for ; Tue, 22 Nov 2022 14:59:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232970AbiKVO7M (ORCPT ); Tue, 22 Nov 2022 09:59:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234144AbiKVO6v (ORCPT ); Tue, 22 Nov 2022 09:58:51 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0BFF6EB6C; Tue, 22 Nov 2022 06:56:26 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 8ACF91F85D; Tue, 22 Nov 2022 14:56:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1669128985; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+loFO6tN5YXsk0bWjK2r+zKhS9ssoaTjODd0fLpHxXw=; b=sfmdqwbLKiTiB7Qi4AyDhjDIvCEMbXR1ZfivjEs/BqcOHbuhw+kprIf2xHCaCTwObQH8a5 CKtGZ10w9JYjpD8IToot/jXIPHYlpgW+5ZS0wbEgEuQpU+1AM+/uz+jrOhnvYaznSjFawR lulkdeUJ9jy+oIMCVvY3OEkd0qOvieo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1669128985; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+loFO6tN5YXsk0bWjK2r+zKhS9ssoaTjODd0fLpHxXw=; b=y42N2ZaNchVaRcELYmUf0n2LuOWXFda2EadO5JNkazxeFEBiX8E/BXEGx+KtlEgs/tzmrX 8ds0XUjamiBkMUDA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 5594413B01; Tue, 22 Nov 2022 14:56:25 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id e3sDFBnjfGMdBAAAMHmgww (envelope-from ); Tue, 22 Nov 2022 14:56:25 +0000 Message-ID: <9489dd1c-012c-8b5d-b670-a27213da287a@suse.cz> Date: Tue, 22 Nov 2022 15:56:25 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 To: Sergey Senozhatsky Cc: Minchan Kim , Petr Vorel , ltp@lists.linux.it, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Nitin Gupta , Jens Axboe , OGAWA Hirofumi , Yang Xu References: <20221107191136.18048-1-pvorel@suse.cz> <3ac740c0-954b-5e68-b413-0adc7bc5a2b5@suse.cz> Content-Language: en-US From: Martin Doucha Subject: Re: [PATCH 0/1] Possible bug in zram on ppc64le on vfat In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11. 11. 22 1:48, Sergey Senozhatsky wrote: > On (22/11/10 15:29), Martin Doucha wrote: >> 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? After 50 test runs on a kernel where the issue is confirmed, I could not reproduce the failure while filling the device from /dev/urandom instead of /dev/zero. The test reported compression ratio around 1.8-2.5 which means the memory usage reported by mm_stat was 10-13MB. Note that I had to disable the other filesystems in the test because some of them kept failing with compression ratio <1. -- Martin Doucha mdoucha@suse.cz QA Engineer for Software Maintenance SUSE LINUX, s.r.o. CORSO IIa Krizikova 148/34 186 00 Prague 8 Czech Republic