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=-2.3 required=3.0 tests=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 07852C3A5A1 for ; Fri, 23 Aug 2019 02:05:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D97C7233A0 for ; Fri, 23 Aug 2019 02:05:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388699AbfHWCFW (ORCPT ); Thu, 22 Aug 2019 22:05:22 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:33669 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733086AbfHWCFW (ORCPT ); Thu, 22 Aug 2019 22:05:22 -0400 Received: from p5de0b6c5.dip0.t-ipconnect.de ([93.224.182.197] helo=nanos) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1i0ywy-0000pN-VG; Fri, 23 Aug 2019 04:05:13 +0200 Date: Fri, 23 Aug 2019 04:05:12 +0200 (CEST) From: Thomas Gleixner To: Andi Kleen cc: kan.liang@linux.intel.com, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, linux-kernel@vger.kernel.org, eranian@google.com Subject: Re: [PATCH V2] perf/x86: Consider pinned events for group validation In-Reply-To: <20190822185522.GE5447@tassilo.jf.intel.com> Message-ID: References: <1566488866-5975-1-git-send-email-kan.liang@linux.intel.com> <20190822182227.GD5447@tassilo.jf.intel.com> <20190822185522.GE5447@tassilo.jf.intel.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 22 Aug 2019, Andi Kleen wrote: > On Thu, Aug 22, 2019 at 08:29:46PM +0200, Thomas Gleixner wrote: > > On Thu, 22 Aug 2019, Andi Kleen wrote: > > > > > > + /* > > > > + * Disable interrupts to prevent the events in this CPU's cpuc > > > > + * going away and getting freed. > > > > + */ > > > > + local_irq_save(flags); > > > > > > I believe it's also needed to disable preemption. Probably should > > > add a comment, or better an explicit preempt_disable() too. > > > > Preemption is implicit disabled by disabling interrupts. > > Yes it is, this is more for documentation. Comment, yes. An explicit preempt_disable() surely not. Thanks, tglx