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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 90A8AC433E9 for ; Mon, 18 Jan 2021 21:20:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5732122D6F for ; Mon, 18 Jan 2021 21:20:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394558AbhARVUL (ORCPT ); Mon, 18 Jan 2021 16:20:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389683AbhARKMP (ORCPT ); Mon, 18 Jan 2021 05:12:15 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D9A0C061575 for ; Mon, 18 Jan 2021 02:11:34 -0800 (PST) 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; bh=/hwtfYk7JSTRHzlSI43O5zHuH29/U9J/Rx5PEUyslTM=; b=3CzDYJIr6Z2nifCGUd/oL6dm/C b2uYaItqCw9R8hw2KArKJGZ+XeAXxoMu/gS/sAdrtJcbpHoD/Qkd+e9QYG5OyRoEVn4VAQiDWW5Ai Sz0AGIJ1l9RLxmnNPW0nuIsMPSEaNcf5bsnUo/AoHeTOydOmhDOe0eu8h7pv7gBJJl32dp343wfhv FjDpTu+xdxUCOP/Elw5zwIAJtvHdbPDNud/6OgMXONj4f3Zy8jPTPPg2OkH4US0l0w1xhqbC+kIfi 9csEYTwipRVBQKgD+hB7dbLZmb4CUCRWMT2QgePPTlahaYfjedE5Fxf7lZbrOBg23aucNDFlRA20l OuzHel7w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1l1RVP-0004Xi-UB; Mon, 18 Jan 2021 10:11:28 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 6F8F530015A; Mon, 18 Jan 2021 11:11:26 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 6061220291083; Mon, 18 Jan 2021 11:11:26 +0100 (CET) Date: Mon, 18 Jan 2021 11:11:26 +0100 From: Peter Zijlstra To: Namhyung Kim Cc: Arnaldo Carvalho de Melo , Jiri Olsa , Ingo Molnar , Mark Rutland , Alexander Shishkin , LKML , Stephane Eranian , Andi Kleen , Ian Rogers , Alexey Alexandrov Subject: Re: [PATCH] perf/core: Emit PERF_RECORD_LOST for pinned events Message-ID: References: <20210118034323.427029-1-namhyung@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210118034323.427029-1-namhyung@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 18, 2021 at 12:43:23PM +0900, Namhyung Kim wrote: > As of now we silently ignore pinned events when it's failed to be > scheduled and make it error state not try to schedule it again. > That means we won't get any samples for the event. > > But there's no way for users to notice and respond to it. Let's > emit a lost event with a new misc bit to indicate this situation. Users should get a read(2) error IIRC, does that not work?