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 E8CB5C3A5A1 for ; Thu, 22 Aug 2019 18:55:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7129205ED for ; Thu, 22 Aug 2019 18:55:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391204AbfHVSz0 (ORCPT ); Thu, 22 Aug 2019 14:55:26 -0400 Received: from mga01.intel.com ([192.55.52.88]:9171 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726142AbfHVSzX (ORCPT ); Thu, 22 Aug 2019 14:55:23 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Aug 2019 11:55:22 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,417,1559545200"; d="scan'208";a="208278528" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.137]) by fmsmga002.fm.intel.com with ESMTP; 22 Aug 2019 11:55:22 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 80D85300FFA; Thu, 22 Aug 2019 11:55:22 -0700 (PDT) Date: Thu, 22 Aug 2019 11:55:22 -0700 From: Andi Kleen To: Thomas Gleixner 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 Message-ID: <20190822185522.GE5447@tassilo.jf.intel.com> References: <1566488866-5975-1-git-send-email-kan.liang@linux.intel.com> <20190822182227.GD5447@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.0 (2019-05-25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. -Andi