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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 CCD9BC11D2F for ; Mon, 24 Feb 2020 12:55:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A61622080D for ; Mon, 24 Feb 2020 12:55:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="hcEgrKvC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727461AbgBXMzc (ORCPT ); Mon, 24 Feb 2020 07:55:32 -0500 Received: from mail.skyhub.de ([5.9.137.197]:35136 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727359AbgBXMzc (ORCPT ); Mon, 24 Feb 2020 07:55:32 -0500 Received: from zn.tnic (p200300EC2F0C0F00754C15A63F97C369.dip0.t-ipconnect.de [IPv6:2003:ec:2f0c:f00:754c:15a6:3f97:c369]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id AB8071EC06AC; Mon, 24 Feb 2020 13:55:30 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1582548930; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=k4n928txEUbCCPofMkDP3ZZra5z8ea63XGeucln+S9o=; b=hcEgrKvC8aJbZJKIXpSmPUbkuWPJ45GGTKMOlNBj45VcmRpraerbeolpRG2w4o3kEkyg++ DXnbFAGNSGv5DBjumtWGw9p54RfLpnlOb1LYs5SFOmQN5F9vFsaH7Sq1vIq7FXP6FO6dI7 we1Dw4v/wR+xNejudVWOfP4qnj9lTOc= Date: Mon, 24 Feb 2020 13:55:25 +0100 From: Borislav Petkov To: Srinivas Pandruvada Cc: tony.luck@intel.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Wilson Subject: Re: [PATCH] x86/mce/therm_throt: Handle case where throttle_active_work() is called on behalf of an offline CPU Message-ID: <20200224125525.GA29318@zn.tnic> References: <20200222162432.497201-1-srinivas.pandruvada@linux.intel.com> <20200222175151.GD11284@zn.tnic> <40989625ca5496a986ca3e595957da83723777f4.camel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <40989625ca5496a986ca3e595957da83723777f4.camel@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 22, 2020 at 04:25:59PM -0800, Srinivas Pandruvada wrote: > If the condition is false, will it prevent offline CPU before executing > next statement and reschedule on another CPU? Although It will not > cause any error or crash but in rare circumstance may print premature > warning/normal message based on the current CPU's state. Why, offline CPU is offline CPU? Btw, I'm asking whether you can do the simpler thing *instead* of your patch. You basically don't run the workqueue callback on offlined CPUs: get_online_cpus(); if (cpu_is_offline(smp_processor_id())) goto out; ... out: put_online_cpus(); Hmm? -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette