From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752531AbbIONmY (ORCPT ); Tue, 15 Sep 2015 09:42:24 -0400 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:50319 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751536AbbIONmV (ORCPT ); Tue, 15 Sep 2015 09:42:21 -0400 Date: Tue, 15 Sep 2015 14:42:09 +0100 From: Russell King - ARM Linux To: Daniel Thompson Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, patches@linaro.org, linaro-kernel@lists.linaro.org, Thomas Gleixner , Hillf Danton Subject: Re: [PATCH v2] arm: Fix backtrace generation when IPI is masked Message-ID: <20150915134208.GT21084@n2100.arm.linux.org.uk> References: <1442222294-2756-1-git-send-email-daniel.thompson@linaro.org> <1442315112-14039-1-git-send-email-daniel.thompson@linaro.org> <20150915113003.GS21084@n2100.arm.linux.org.uk> <55F819DE.9040704@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55F819DE.9040704@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 15, 2015 at 02:15:10PM +0100, Daniel Thompson wrote: > Actually it already gets masked out. The argument to raise_nmi() points to a > data structure owned by the backtrace library functions and this structure > if altered during the execution of nmi_cpu_backtrace() to clear the calling > CPU. > > I had originally planned to use cpumask_test_and_clear_cpu() for the > conditional branch but that would be broken because nmi_cpu_backtrace() > would become a nop if we clear anything from the mask before calling it! > > I guess I should add a comment about this to save us from broken but > "obviously correct" cleanups in the future... Absolutely. -- FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.