Received: by 2002:a05:6a10:22f:0:0:0:0 with SMTP id 15csp21789pxk; Tue, 15 Sep 2020 16:37:48 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwPbOpZMvzwvUqHLXire/sWpiXHlPthp/fCKVszffeIwsgB/X68MWcFUBC8YkQEkazsfsXl X-Received: by 2002:a17:906:cd0d:: with SMTP id oz13mr22342524ejb.212.1600213068264; Tue, 15 Sep 2020 16:37:48 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1600213068; cv=none; d=google.com; s=arc-20160816; b=c3TvKzXmpYdXhdjqmvaKV7dKJ76Im6ohYXDrFtG/Dndcosn6nBTpBetlu2uKy60FR5 6yMbinOaNfozkCdP3INuguDVFL80FJJetH0FU+JcftJDNzalI9NcjhxBXXFKY02RA9rc z5ExCirvQQFrwyXOu+TCDNC5Ex2BSn8vy1ba4wXvrguDCcq6ne2VGOJmo5Sk33F/tLKh eEcmb25q2wAXUwkefHzZsFTNVAcrjReW4g+qWBl/GS4qG2q80YmLyJLEIGoNLv9gTxRZ wVgDwcm1++1ppMrWHnXlklwRsdmHhoYxjOJuIaRpJVUmrmPOViGC/rUYjMGjB54kN0Sy 7bBQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:dkim-signature; bh=VY3FI+8ua5GfWFJfcYL9CJDi5GxfS9ipQFMk0egquPM=; b=TzzutRNwwHZI7RHydOChOMaF7RxhN03ZN09ennKYoZNC+z4RaN6AVnw+Oqh8LKG9Uy v9Zl2sIvHSwkJjfp6Xq2IEOkDwtBsAxoQKg+WIbL9/7BXWzZ2w0ZzeAapf7feL3AZ4Kz rCoHWDuTB1yiDOmvikqc5KCeXV+KTDbTLAFZMUvWaDOqd9mX4Y52aPYiB7OzFr8B4FWG cbWVez+w2A5BhUDzBR4o4/Kgw/kSD/6wE3AI9gk40UfTqOEyAsSOYeTfcI3nNF2izYUH ZT8yZREdGMgjAej/1HBWqXKmgeL/AGC7yt7oZiYeMsuwRScFVLVoIJbUtg0PjK0iJzK1 o4Tg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linux-foundation.org header.s=google header.b=Ejf+nB2H; spf=pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-ext4-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id r8si10898701edw.288.2020.09.15.16.37.16; Tue, 15 Sep 2020 16:37:48 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linux-foundation.org header.s=google header.b=Ejf+nB2H; spf=pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-ext4-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726921AbgIOXgc (ORCPT + 99 others); Tue, 15 Sep 2020 19:36:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726383AbgIOXgG (ORCPT ); Tue, 15 Sep 2020 19:36:06 -0400 Received: from mail-lf1-x142.google.com (mail-lf1-x142.google.com [IPv6:2a00:1450:4864:20::142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 837B3C06174A for ; Tue, 15 Sep 2020 16:36:04 -0700 (PDT) Received: by mail-lf1-x142.google.com with SMTP id q8so4937107lfb.6 for ; Tue, 15 Sep 2020 16:36:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=VY3FI+8ua5GfWFJfcYL9CJDi5GxfS9ipQFMk0egquPM=; b=Ejf+nB2H8r1U6BUXghESSW2la6WPBsGO2KQMBfcOZ04frdMfiw6sT10vXttnHODQ6i rvToxlK44vQDz8BHh8az9FEP/q3ZzjKoTGWJmy+a9q8ESyZu13UWfzvASKK25VnT1DDc EgHYogXAOZ3tXTdP4JYasoGmltggzQdxf32e4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=VY3FI+8ua5GfWFJfcYL9CJDi5GxfS9ipQFMk0egquPM=; b=sR8q11QpBJlXBnjBbt0chFfC81B+dBBJzRM/lBOC1OIKk98Gi0LBhS3mV538HvwXK6 vP/Cb26KbUr/PjmbhrD/WX6FVT8ZODTBQSMBP8kNdyhBluVb0wBwdD/LUggSPA06svZB dLTW01lzFHK3lrutTzK1am102vQb/yVRCs532WKAVOIe20z5e6ur5QO1X6YNpnoUIIMT o+GJsd9HftsUb5ndvWfWOeqMffeEMyahbFOdLPVCRBB8Fp9GR9Whm/b1n3dar6FK4PDK DPOcsHcfldtzw5Bq5Bzy9nHGw1COuf7UAjine23sgX2SY1qGfLkJUnfmKWHI9OC+7wBD wRUQ== X-Gm-Message-State: AOAM533NgWzQ52XhTEzb/mIcjQ9Hiq/B4gjbLgonr4qrOBpLJ/7El0i0 INLWCI19u+YkopYLrjmjZMKhs0fEGXvgEA== X-Received: by 2002:a19:4a8a:: with SMTP id x132mr6360458lfa.423.1600212962811; Tue, 15 Sep 2020 16:36:02 -0700 (PDT) Received: from mail-lf1-f44.google.com (mail-lf1-f44.google.com. [209.85.167.44]) by smtp.gmail.com with ESMTPSA id c28sm4247811lfh.98.2020.09.15.16.36.01 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 15 Sep 2020 16:36:01 -0700 (PDT) Received: by mail-lf1-f44.google.com with SMTP id y11so4943064lfl.5 for ; Tue, 15 Sep 2020 16:36:01 -0700 (PDT) X-Received: by 2002:a19:4186:: with SMTP id o128mr6576901lfa.148.1600212961230; Tue, 15 Sep 2020 16:36:01 -0700 (PDT) MIME-Version: 1.0 References: <0daf6ae6-422c-dd46-f85a-e83f6e1d1113@MichaelLarabel.com> <20200912143704.GB6583@casper.infradead.org> <658ae026-32d9-0a25-5a59-9c510d6898d5@MichaelLarabel.com> <9550725a-2d3f-fa35-1410-cae912e128b9@tessares.net> <37989469-f88c-199b-d779-ed41bc65fe56@tessares.net> In-Reply-To: <37989469-f88c-199b-d779-ed41bc65fe56@tessares.net> From: Linus Torvalds Date: Tue, 15 Sep 2020 16:35:45 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Kernel Benchmarking To: Matthieu Baerts Cc: Michael Larabel , Matthew Wilcox , Amir Goldstein , "Ted Ts'o" , Andreas Dilger , Ext4 Developers List , Jan Kara , linux-fsdevel Content-Type: text/plain; charset="UTF-8" Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Tue, Sep 15, 2020 at 12:56 PM Matthieu Baerts wrote: > > I am sorry, I am not sure how to verify this. I guess it was one > processor because I removed "-smp 2" option from qemu. So I guess it > switched to a uniprocessor mode. Ok, that all sounds fine. So yes, your problem happens even with just one CPU, and it's not any subtle SMP race. Which is all good - apart from the bug existing in the first place, of course. It just reinforces the "it's probably a latent deadlock" thing. Linus