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=-5.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 86566C43441 for ; Thu, 22 Nov 2018 12:27:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 407D120684 for ; Thu, 22 Nov 2018 12:27:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="gN8XvJOL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 407D120684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395057AbeKVXGZ (ORCPT ); Thu, 22 Nov 2018 18:06:25 -0500 Received: from merlin.infradead.org ([205.233.59.134]:39662 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394865AbeKVXGY (ORCPT ); Thu, 22 Nov 2018 18:06:24 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=6GoQshdtTCtgMebtwlHObzPjr944dMKihJzDk8JnA+E=; b=gN8XvJOLSMf9Ga/u/ly10Llmm d94ZfD94B0B6/m6mCzv91TIyY3eHgeFCJL9dj5fuS93nGq7DX+i8Y/H/a3UzqrpyuLk6nLAbUoibz jFwPpe1WGtzIzPWssrpuIWEWzsayQsj2a9+m+cSKL3e8BQ6v8073C2AsmNS4QxtsSb8E44vmMhFcu au6wPlvaM6ksRF/BkswOOa1rYEsi/HVInl7A0PNOie2KYXkxJxLYQSrNnaKoKFBIZUkaZ3rktsycV iaKN4IdixwWgG7LgClwd5g0QSrNQ4FVwLAyV1IPpvfzP031JzYzlPfPl+O5p3oaes5Qa76i3cweT+ 2vWyx7Lvw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gPo4E-0001H5-NY; Thu, 22 Nov 2018 12:26:49 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 1753B2029FD58; Thu, 22 Nov 2018 13:26:37 +0100 (CET) Date: Thu, 22 Nov 2018 13:26:37 +0100 From: Peter Zijlstra To: Andrew Murray Cc: Ingo Molnar , Arnaldo Carvalho de Melo , Shawn Guo , Sascha Hauer , Will Deacon , Mark Rutland , Benjamin Herrenschmidt , Thomas Gleixner , Borislav Petkov , x86@kernel.org, linux-alpha@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 00/10] perf/core: Generalise event exclusion checking Message-ID: <20181122122637.GS2131@hirez.programming.kicks-ass.net> References: <1542363853-13849-1-git-send-email-andrew.murray@arm.com> <20181119130800.GE9761@hirez.programming.kicks-ass.net> <20181122122142.GI42987@e119886-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181122122142.GI42987@e119886-lin.cambridge.arm.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 Thu, Nov 22, 2018 at 12:21:43PM +0000, Andrew Murray wrote: > On Mon, Nov 19, 2018 at 02:08:00PM +0100, Peter Zijlstra wrote: > > diff --git a/kernel/events/core.c b/kernel/events/core.c > > index 84530ab358c3..d76b724177b9 100644 > > --- a/kernel/events/core.c > > +++ b/kernel/events/core.c > > @@ -9772,6 +9772,14 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event) > > if (ctx) > > perf_event_ctx_unlock(event->group_leader, ctx); > > > > + if (!ret) { > > + if ((pmu->capabilities & PERF_PMU_CAP_EXCLUDE) || > > + event_has_exclude_flags(event)) { > > + event->destroy(event); > > + ret = -EINVAL; > > + } > > + } > > + > > I don't quite follow this logic. Should that not have been: > > if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUDE) && > event_has_exclude_flags(event)) { > > Meaning that if an event has any exclude flags but the pmu doesn't > have the capability to handle them then error. Uhm, yes. Brainfart on my side that. > If you're happy with my proposed logic, then would it also make > sense to move this before the call to the pmu->event_init ? I'm not sure that can work; I think we need ->event_init() first such that it can -ENOENT. Only after ->event_init() returns success can we be certain of @pmu.