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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 6B176C2D0E4 for ; Tue, 24 Nov 2020 08:52:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 114052075A for ; Tue, 24 Nov 2020 08:52:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OCLmvw72" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730759AbgKXIvn (ORCPT ); Tue, 24 Nov 2020 03:51:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730893AbgKXIvm (ORCPT ); Tue, 24 Nov 2020 03:51:42 -0500 Received: from mail-io1-xd44.google.com (mail-io1-xd44.google.com [IPv6:2607:f8b0:4864:20::d44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 066BAC0613CF for ; Tue, 24 Nov 2020 00:51:42 -0800 (PST) Received: by mail-io1-xd44.google.com with SMTP id o11so21093743ioo.11 for ; Tue, 24 Nov 2020 00:51:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=6G34B8UuYAuKelScbRyT107JffrqzzUEbW2EtqDPeNY=; b=OCLmvw72ObHFVDiScD08rJnqQbrVi8VXSGtvRWItHCcnkmYaemxWdRri2G9j4Bf0yw EJ8oZM3CuAZYL84IjKu8PklfLunlpeToKts4l3JaJ3tizyjI0neNgO9ymmksO8CFuMR1 osLmtVR/TQ9e9JnZsO7dTD/t0vmtFYMBtsoQKBIV9OexYzSkshmtTeqTBFpjTvhMRsRe PX/X/cfhBEhL1Ri5HDSxWEZC/en2UzfnWor/b9wkOyjKo7A0QP1F4Z31jkw7yPCpt8vG m0+iV84fRYSQ+OSrxt/7FrtLavEqmTBc9PvJ3N4g5JFRITFlQyFWMNLQSB9xQiDeiOPc L5Zg== 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=6G34B8UuYAuKelScbRyT107JffrqzzUEbW2EtqDPeNY=; b=TguqRTTIrpCaEvl2b2xDfpU6NZOx9c/VbF+m2d0VG60zsuwrCcAZyT5nkugQ3fttTV abMeCfEq7wR+Y8I2ZJxV5GaRJwjQQgtuRMN/fNx0/fSGGdfVv86wX/DIpa8pRErTXE9I XK/cxT8jJY6bjKgv58qAaaq/BPJcFlw31HiDugqsFuOSo1JbxBFxuuuf9CB5IE9rmI2p TNS/zYL1lpxbKIlbVUSgOZ+GNCr7XR3/clekUo+zsKEjkSEk5+OZNtkEFiqDHnoPtGF6 yZpTYaoLtlYoXHkf6LqR4Q5SesXO519UdrOAmtYEUlnlzS9LzCkQRJmeDVM6NyjVObhk bybw== X-Gm-Message-State: AOAM530aXyNJxKVljcbMo2Kn630ZioAuxZ6XIRQ9D62rdOKbr6+TohxD h7BBUul9FLTFpniDiS+D5HmniRV979ux/CPwPg== X-Google-Smtp-Source: ABdhPJwQVaVeoun07nUGXLW7b3J+SnUIqGDp6QW3kkFX/IbJQ9XwMJGyLEMzGMIi86b6DnlWQx17SZXeE1E+aPRWtNE= X-Received: by 2002:a02:a413:: with SMTP id c19mr3636261jal.7.1606207901458; Tue, 24 Nov 2020 00:51:41 -0800 (PST) MIME-Version: 1.0 References: <1606109846-13688-1-git-send-email-kernelfans@gmail.com> <20201123140552.GN3021@hirez.programming.kicks-ass.net> In-Reply-To: <20201123140552.GN3021@hirez.programming.kicks-ass.net> From: Pingfan Liu Date: Tue, 24 Nov 2020 16:50:45 +0800 Message-ID: Subject: Re: [PATCH 1/2] events/core: introduce perf_pmu_disable_all() to turn off all PMU To: Peter Zijlstra Cc: LKML , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Borislav Petkov , "H. Peter Anvin" , Omar Sandoval , Andrew Morton , Mike Rapoport , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 23, 2020 at 10:05 PM Peter Zijlstra wrote: > > On Mon, Nov 23, 2020 at 01:37:25PM +0800, Pingfan Liu wrote: > > > +/* When crashed, other cpus hang in idle loop, so here do an emergency job under no lock */ > > -ENOPARSE, -ETOOLONG > > > +void perf_pmu_disable_all(void) > > +{ > > + struct pmu *pmu; > > + > > + list_for_each_entry(pmu, &pmus, entry) > > + if (pmu->pmu_disable) > > + pmu->pmu_disable(pmu); > > +} > > This violates both locking rules and coding style. Oops. I will re-work on it to see how to run it safely on crashed context. Thanks, Pingfan