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=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 4FC7BECE587 for ; Tue, 1 Oct 2019 18:15:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1CF7E20B7C for ; Tue, 1 Oct 2019 18:15:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="jT6aYSk+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732113AbfJASPP (ORCPT ); Tue, 1 Oct 2019 14:15:15 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:43965 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727012AbfJASPO (ORCPT ); Tue, 1 Oct 2019 14:15:14 -0400 Received: by mail-wr1-f68.google.com with SMTP id q17so16672170wrx.10 for ; Tue, 01 Oct 2019 11:15:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=YgJCteJu2BcK46pwUgWjXEExK/YmgMP+ugfQEXB9MmU=; b=jT6aYSk+jwGRAiSBelGcOX1Hrdn93yDj1/lfZzRxeykwZggAXTFeMq3c/+HPhrYvf2 zvOdnLS4BlOCJR458+IIiSWNr/dxPJd98W32wZ+i7HDNRWFYPsgdIULTvruamcI10VHd qKuE3elC5DgnLGe3EjB8i8BldmbM73xm4XfVAHbCIFV/UbXupvr5G7WUUHTN8KqjICwo AYIrp3AMWqbFkFMp3qg5GModhNJt0jMXx6KS63g9txBTJ+oJAon4/iqpzV0+Vxxn6rZl ntZ1Kcp3eoD8YHGo5umSyJwutTN24cO3uLR5JjsMtmxNlJG5Y4yKivznhJDxm5leYH7S 6FbA== 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=YgJCteJu2BcK46pwUgWjXEExK/YmgMP+ugfQEXB9MmU=; b=O8niBRi8w1j+rOgG5goOUbmVRSr+v2muceSJApmyHM9CiEhD8Tyfd0UH2lQOw/E15X xiOA6+H/EZgpTMeMQOA0qN7Kf1V43d+MUddEDgpSQddAPgeW47cJBQjhe3dbPYAhZ/Ab t9DjWZosEfr2LjmNGq8Z1NvKz3sJb8GKoLkikNNmWNIWzYosugUyeiAV9Helcnxz73NH b0ZG0Clh98wGfwWF2ia/e4yQ5ztW6AE2M77DHeJTvkYZKPE5XqYvgvEuNq3HtGh18WiI 1hYPzQ3BXmNKbbbBr1w0i/ozHjkW2oZLKuaf/dVgIs6gx5WZa5L3KPNWAmwU9jPF2ffO 442g== X-Gm-Message-State: APjAAAXZpl/DpZwtuE4c2Rx0Jx3QUurToh1ifA/jQ1WQvBx+S2JDoRcw 4+AyAMTDmLyYWVhUPo9CX1fhxaFVSPbYID+4XEuDmA== X-Google-Smtp-Source: APXvYqzcqO5Pq3kgDizzsdzSixi6NQ83JHy7bqSusFNzosiGFQnYz2xTI+ymA+EZ8oo/TrC+bHz00N1swRHz2cWlepE= X-Received: by 2002:adf:d08b:: with SMTP id y11mr19827984wrh.50.1569953712760; Tue, 01 Oct 2019 11:15:12 -0700 (PDT) MIME-Version: 1.0 References: <20190928123905.GA97048@gmail.com> <20191001071921.GJ4519@hirez.programming.kicks-ass.net> In-Reply-To: <20191001071921.GJ4519@hirez.programming.kicks-ass.net> From: John Stultz Date: Tue, 1 Oct 2019 11:15:01 -0700 Message-ID: Subject: Re: [GIT PULL] scheduler fixes To: Peter Zijlstra Cc: Ingo Molnar , Linus Torvalds , Linux Kernel Mailing List , Thomas Gleixner , Andrew Morton , Mathieu Desnoyers , "Eric W. Biederman" , Joel Fernandes , Alistair Delva Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 1, 2019 at 12:19 AM Peter Zijlstra wrote: > > On Mon, Sep 30, 2019 at 04:45:49PM -0700, John Stultz wrote: > > Reverting the following patches: > > > "sched/membarrier: Fix p->mm->membarrier_state racy load" > > ARGH, I fudged it... please try: > > > diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c > index a39bed2c784f..168479a7d61b 100644 > --- a/kernel/sched/membarrier.c > +++ b/kernel/sched/membarrier.c > @@ -174,7 +174,6 @@ static int membarrier_private_expedited(int flags) > */ > if (cpu == raw_smp_processor_id()) > continue; > - rcu_read_lock(); > p = rcu_dereference(cpu_rq(cpu)->curr); > if (p && p->mm == mm) > __cpumask_set_cpu(cpu, tmpmask); Yep. Looks like that solves it! Tested-by: John Stultz Thanks so much for the quick turnaround! -john