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=-0.8 required=3.0 tests=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 1953EC35280 for ; Thu, 7 May 2020 21:47:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 000FE20870 for ; Thu, 7 May 2020 21:47:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727072AbgEGVrB (ORCPT ); Thu, 7 May 2020 17:47:01 -0400 Received: from mga09.intel.com ([134.134.136.24]:30012 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726437AbgEGVrA (ORCPT ); Thu, 7 May 2020 17:47:00 -0400 IronPort-SDR: lZy1lW9BpjeakLNig3qvWwA18fGMQhtZVfMP07O7UGbbtjgYhWNCdb45cw1jmvINoSVmYsad0d qoq8vHXJ1c0A== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 May 2020 14:46:54 -0700 IronPort-SDR: XSzS7dTe6Wy7C+q//uzNDJRFqXYcvr54hWsflNNGVA2u2d/Yo2Vb3KSk0fM0DqTCqOyLDGNX46 U16slWjhO8sQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,365,1583222400"; d="scan'208";a="462004281" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.21]) by fmsmga005.fm.intel.com with ESMTP; 07 May 2020 14:46:52 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 5A34B301C1B; Thu, 7 May 2020 14:46:52 -0700 (PDT) Date: Thu, 7 May 2020 14:46:52 -0700 From: Andi Kleen To: Ian Rogers Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , KP Singh , Kajol Jain , John Garry , Jin Yao , Kan Liang , Cong Wang , Kim Phillips , LKML , Networking , bpf , linux-perf-users , Stephane Eranian Subject: Re: [RFC PATCH 0/7] Share events between metrics Message-ID: <20200507214652.GC3538@tassilo.jf.intel.com> References: <20200507081436.49071-1-irogers@google.com> <20200507174835.GB3538@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > - without this change events within a metric may get scheduled > > together, after they may appear as part of a larger group and be > > multiplexed at different times, lowering accuracy - however, less > > multiplexing may compensate for this. > > I agree the heuristic in this patch set is naive and would welcome to > improve it from your toplev experience. I think this change is > progress on TopDownL1 - would you agree? TopdownL1 in non SMT mode should always fit. Inside a group deduping always makes sense. The problem is SMT mode where it doesn't fit. toplev tries to group each node and each level together. > > I'm wondering if what is needed are flags to control behavior. For > example, avoiding the use of groups altogether. For TopDownL1 I see. Yes the current situation isn't great. For Topdown your patch clearly is an improvement, I'm not sure it's for everything though. Probably the advanced heuristics are only useful for a few formulas, most are very simple. So maybe it's ok. I guess would need some testing over the existing formulas. -Andi