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=-2.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, 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 BED40C04AB1 for ; Sat, 11 May 2019 21:45:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D1D4217D6 for ; Sat, 11 May 2019 21:45:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amarulasolutions.com header.i=@amarulasolutions.com header.b="BdtQOkaY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726360AbfEKVpc (ORCPT ); Sat, 11 May 2019 17:45:32 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:45307 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726033AbfEKVpb (ORCPT ); Sat, 11 May 2019 17:45:31 -0400 Received: by mail-wr1-f68.google.com with SMTP id b18so1296385wrq.12 for ; Sat, 11 May 2019 14:45:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amarulasolutions.com; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=PPBGZkBoQo3Ukc85VDhfZeXzhApaOOcUc2m8QXSsq3Q=; b=BdtQOkaYnoAFy22dv+qrBSLmW3PUjkU/CFTnc3YG8/29yPpqaoX0EIKu7kcBZIJpnU 3C+SqvRVMrl3x9puWWU94sAdFwW9rVE2ILksZY780tsnWfUJghwcZlaW3HpzAqvrvvhO UQp78xNTYidqyrNCzk8qmyjmzuN97i5qkMqUw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=PPBGZkBoQo3Ukc85VDhfZeXzhApaOOcUc2m8QXSsq3Q=; b=bV/8P95cNDsZ0/Bu9S9rGUp1u1Hdj86nAgd4nifJxSc7W5/JqNOA/JuaVGQI5Fr7eW eRyfQFSqu8UhOwfv1enUTuepbpLLIqqKt21eim2/cowBzHbGmVp2eBNXxafY5palynMo 7G2+Lnuia1KWj1t+HaSs7cfZUQq0Mxj7oh0lJHJ0rokxf+RTgzKsHiPxxwp+jNnZElnQ rUuJjv1u73sq9MUUuRVF8StaBfmtzr48TdsS3vTChmPUGSBqbKDWN9qLuKMBT4XvI7Px 2QqZpjZMJpovby7YhQb7GdcUd5cANa0itZ76r672qFspJTbj4gCex3/O+jnvNfgk9RRp bojQ== X-Gm-Message-State: APjAAAUKQPa8zROnBf/qnKr+h2SNOftq7SOe+cA8q3+D6rdsK2mvZ6Ln dGo/bU/WSLxLISXhQdj+s0frRA== X-Google-Smtp-Source: APXvYqyWpxql6Ydh91GFk5ZwhNDajUu3C6mPZiyE4ur8CDdVGlyqt4DOADmT05wNsx5HS3s/R8ZwVw== X-Received: by 2002:a05:6000:1201:: with SMTP id e1mr11894162wrx.136.1557611130178; Sat, 11 May 2019 14:45:30 -0700 (PDT) Received: from andrea ([89.22.71.151]) by smtp.gmail.com with ESMTPSA id o16sm8236649wro.63.2019.05.11.14.45.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 11 May 2019 14:45:29 -0700 (PDT) Date: Sat, 11 May 2019 23:45:20 +0200 From: Andrea Parri To: "Paul E. McKenney" Cc: Peter Zijlstra , Steven Rostedt , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Juri Lelli , Morten Rasmussen , joelaf@google.com, Vincent Guittot , Sebastian Andrzej Siewior Subject: Re: Question about sched_setaffinity() Message-ID: <20190511214520.GA3251@andrea> References: <20190430105129.GA3923@linux.ibm.com> <20190430115551.GT2623@hirez.programming.kicks-ass.net> <20190501191213.GX3923@linux.ibm.com> <20190501151655.51469a4c@gandalf.local.home> <20190501202713.GY3923@linux.ibm.com> <20190507221613.GA11057@linux.ibm.com> <20190509173654.GA23530@linux.ibm.com> <20190509193625.GA12455@linux.ibm.com> <20190510120819.GR2589@hirez.programming.kicks-ass.net> <20190510230742.GY3923@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190510230742.GY3923@linux.ibm.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > The below trace explain the issue. Some Paul person did it, see below. > > It's broken per construction :-) > > *facepalm* Hence the very strange ->cpus_allowed mask. I really > should have figured that one out. > > The fix is straightforward. I just added "rcutorture.shuffle_interval=0" > to the TRIVIAL.boot file, which stops rcutorture from shuffling its > kthreads around. I added the option to the file and I didn't reproduce the issue. > Please accept my apologies for the hassle, and thank you for tracking > this down!!! Peter (echoing Paul): Thank you for pointing that shuffler out! Andrea