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=-11.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 E760BC07E99 for ; Fri, 9 Jul 2021 12:51:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6D08613B0 for ; Fri, 9 Jul 2021 12:51:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231431AbhGIMyT (ORCPT ); Fri, 9 Jul 2021 08:54:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:46062 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229671AbhGIMyT (ORCPT ); Fri, 9 Jul 2021 08:54:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 953F36138C; Fri, 9 Jul 2021 12:51:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625835095; bh=GU1jhgi5wPMaeA8R0nZaTzda3Y0S9v6LWbgT7i4/SkY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tjqy5QkSAmty9r6mK5N/qGFwzTEXpvsWspiQDskLAm925ierVP2EdCW3fd3T1g9HL h1TMykjV2FsFLFVVxe/RvYmHcxfF+QL6L0dl2SNtPUlvgw208lBftym/8+aE1pT6kS gcvLCQUU3VbSlfDBQAXHt/9DpSOdRmoh9L++Fqb25jf+Ezmqb28Sao5n5SKoyfebwa C0HoWqZPzrYTee7JVVNiQst/ROpASpVlD3orXw+5f9cQSy0VDJqOsw/T1FWQX+hJBj F9BGRwaCKJ+y2lMu4j0zIxRrkkjtJX/stblKO5pEFylgryAXfwxcgejdgJyRkuq/a6 sRppPiz6iJaDA== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id D9E5E40B1A; Fri, 9 Jul 2021 09:51:31 -0300 (-03) Date: Fri, 9 Jul 2021 09:51:31 -0300 From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: "Liang, Kan" , Ingo Molnar , Jiri Olsa , linux-kernel , Yao Jin , Kan Liang Subject: Re: [PATCH] perf record: Add a dummy event for a hybrid system Message-ID: References: <1625760212-18441-1-git-send-email-kan.liang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Thu, Jul 08, 2021 at 10:32:13PM -0700, Namhyung Kim escreveu: > On Thu, Jul 8, 2021 at 9:05 AM wrote: > > > > From: Kan Liang > > > > Some symbols may not be resolved if a user only monitor one type of PMU. > > > > $ sudo perf record -e cpu_atom/branch-instructions/ ./big_small_workload > > $ sudo perf report –stdio > > # Overhead Command Shared Object Symbol > > # ........ ......... ................. > > # ...................................... > > # > > 28.02% perf-exec [unknown] [.] 0x0000000000401cf6 > > 11.32% perf-exec [unknown] [.] 0x0000000000401d04 > > 10.90% perf-exec [unknown] [.] 0x0000000000401d11 > > 10.61% perf-exec [unknown] [.] 0x0000000000401cfc > > > > To parse symbols, the side-band events, e.g., COMM, which are generated > > by the kernel are required. To decide whether to generate the side-band > > event, the kernel relies on the event_filter_match() to filter the > > unrelated events. On a hybrid system, the event_filter_match() further > > checks the CPU mask of the current enabled PMU. If an event is collected > > on the CPU which doesn't have an enabled PMU, it's treated as an > > unrelated event. > > > > The "big_small_workload" is created in a big core, but runs on a small > > core. The side-band events are filtered, because the user only monitors > > the PMU of the small core. The big core PMU is not enabled. > > > > For a hybrid system, a dummy event is required to generate the complete > > side-band events. > > > > Signed-off-by: Kan Liang > > Acked-by: Namhyung Kim Thanks, applied. - Arnaldo