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 47C7CC433EF for ; Tue, 21 Jun 2022 12:16:18 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id D6B5A3C9430 for ; Tue, 21 Jun 2022 14:16:15 +0200 (CEST) Received: from in-2.smtp.seeweb.it (in-2.smtp.seeweb.it [217.194.8.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id 1F0263C034D for ; Tue, 21 Jun 2022 14:16:04 +0200 (CEST) Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-2.smtp.seeweb.it (Postfix) with ESMTPS id 94D4B6008D1 for ; Tue, 21 Jun 2022 14:16:03 +0200 (CEST) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id C256321A70; Tue, 21 Jun 2022 12:16:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1655813762; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=iD1d7pIt6IG6wkijy+I6yc1eZUq16bB27ONeDlNai34=; b=krTX61yjoOXvT7282YBglTO7BDOnGLookHrrOnMP51WY2Q7xIvU01Ue5/zTvXAaaWthUbd I9Tt52EfouSji/cAAaVtKzX7M2YfbE9+ECU9eBo/6nArdi8sl7dR9vyruFWi55p5Coz0g5 scp2aD7Bpb8pz+zui6aInH3WOyUIlas= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1655813762; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=iD1d7pIt6IG6wkijy+I6yc1eZUq16bB27ONeDlNai34=; b=xUooqHGGWrxZM0o03EwAUJLz+8waPM+FaAKxK/QRR2fECZ8grCBefqSNY9Y7fxCC6anhZJ SkoeiSN8ko/qgrAw== Received: from g78 (unknown [10.163.24.226]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 63A4F2C141; Tue, 21 Jun 2022 12:16:02 +0000 (UTC) References: <010001816f3c352e-f5ee78c6-1425-42f5-b673-409a0a92ef74-000000@email.amazonses.com> <11d7d8a6-c062-03aa-7e7c-f7d3c3c2f095@jv-coder.de> <60876a29-d589-1de9-b4fd-a9000b8e7d68@jv-coder.de> <871qvi5r97.fsf@suse.de> User-agent: mu4e 1.6.10; emacs 28.1 From: Richard Palethorpe To: Li Wang Date: Tue, 21 Jun 2022 12:38:40 +0100 In-reply-to: Message-ID: <87wnda43ge.fsf@suse.de> MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.102.4 at in-2.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [REGRESSION] lkft ltp for 6763a36 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: , Reply-To: rpalethorpe@suse.de Cc: LTP List Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" Hello Li, Li Wang writes: > On Tue, Jun 21, 2022 at 4:56 PM Richard Palethorpe wrote: > > Hello, > > Joerg Vehlow writes: > > > Hi Jan, > > > > Am 6/21/2022 um 9:22 AM schrieb Jan Stancek: > >> On Tue, Jun 21, 2022 at 9:15 AM Joerg Vehlow wrote: > >>> > >>> Hi, > >>> > >>> Am 6/17/2022 um 3:17 AM schrieb lkft@linaro.org: > >>>> * qemu_i386, ltp-fs-tests > >>>> - read_all_proc > >>> I've seen this test fail a lot, has anyone ever tried to analyze it? I > >>> was unable to reproduce the problem when running the test in isolation. > >> > >> I see it hit timeouts too (read_all_sys as well). I think it needs > >> runtime restored to 5minutes as well, atm. it has 30s. > > Didn't think about that, but at least for the failures I've seen, this > > is not the reason. The message printed by the test is "Test timeout 5 > > minutes exceeded." > > > > Joerg > > The main issue with read_all is that it also acts as a stress > test. Reading some files in proc and sys is very resource intensive > (e.g. due to lock contention) and varies depending on what state the > system is in. On some systems this test will take a long time. Also > there are some files which have to be filtered from the test. This > varies by system as well. > > Does it make sense to have a lite version of read_all_sys? > which may only go through files sequentially or under slight stress. IIRC the reason I started doing it in parallel is because sequential opens and reads are even slower and unreliable. Some level of parallism is required, but too much and it causes issues. Thinking about it now, on a single or two core system only one worker process will be spawned. Which could get blocked for a long time on some reads because of the way some sys/proc files are implemented. The worker count can be overridden with -w if someone wants to try increasing it to see if that actually helps on systems with <3 cpus. Also the number of reads is set to 3 in the runtest file, that can be reduced to 1 with -r. > > With regard to this stressful read_all, I guess we can put into a dedicated > set and run separately in stress testing. I don't think I'd want to run that. IMO just doing enough to test parallel accesses is whats required. More than that we will run into diminishing returns . However I'm not against creating another runtest file/entry for that. On bigger systems I think the test is already quite limited even though it does 3 reads. It only spwans a max of 15 workers which should prevent it from causing huge lock contention on machines with >16 CPUs. At least I've not seen problems with that. It looks like the log from lkft is for a smaller machine? -- Thank you, Richard. -- Mailing list info: https://lists.linux.it/listinfo/ltp