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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D716AC433E0 for ; Wed, 27 May 2020 06:31:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE7A520787 for ; Wed, 27 May 2020 06:31:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728477AbgE0GbI (ORCPT ); Wed, 27 May 2020 02:31:08 -0400 Received: from mga06.intel.com ([134.134.136.31]:57167 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726337AbgE0GbH (ORCPT ); Wed, 27 May 2020 02:31:07 -0400 IronPort-SDR: BRz5MZMQnvI4nRBN/xc0vBsMelCYOlw8EpZzQVxn1k3OpKncgwTlicqO7kCjZfYUqFiUCcZGZC BSALCp7SbTzA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 May 2020 23:31:06 -0700 IronPort-SDR: aR1qW7a7nJ+0R8gC5zNBvxg5jKW205prOvVa7RoSOa4aXsZThBK/C/yG7M4/7gptp1Or1yyoZQ gmZCyEf32kLA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,440,1583222400"; d="scan'208";a="375935788" Received: from yjin15-mobl1.ccr.corp.intel.com (HELO [10.238.5.239]) ([10.238.5.239]) by fmsmga001.fm.intel.com with ESMTP; 26 May 2020 23:31:04 -0700 Subject: Re: [PATCH v2 1/2] perf evlist: Ensure grouped events with same cpu map From: "Jin, Yao" To: Jiri Olsa Cc: acme@kernel.org, jolsa@kernel.org, peterz@infradead.org, mingo@redhat.com, alexander.shishkin@linux.intel.com, Linux-kernel@vger.kernel.org, ak@linux.intel.com, kan.liang@intel.com, yao.jin@intel.com References: <20200525065559.6422-1-yao.jin@linux.intel.com> <20200526115155.GE333164@krava> <32c4663a-6934-2a2d-79e2-7a335e3629a2@linux.intel.com> Message-ID: Date: Wed, 27 May 2020 14:31:03 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.8.1 MIME-Version: 1.0 In-Reply-To: <32c4663a-6934-2a2d-79e2-7a335e3629a2@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jiri, On 5/27/2020 11:20 AM, Jin, Yao wrote: > Hi Jiri, > > On 5/26/2020 7:51 PM, Jiri Olsa wrote: >> On Mon, May 25, 2020 at 02:55:58PM +0800, Jin Yao wrote: >> >> SNIP >> >>> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c >>> index 2a9de6491700..1161cffc0688 100644 >>> --- a/tools/perf/util/evlist.c >>> +++ b/tools/perf/util/evlist.c >>> @@ -1704,3 +1704,52 @@ struct evsel *perf_evlist__reset_weak_group(struct evlist *evsel_list, >>>       } >>>       return leader; >>>   } >>> + >>> +static bool cpus_map_matched(struct evsel *prev, struct evsel *evsel) >>> +{ >>> +    if (evsel->core.cpus->nr != prev->core.cpus->nr) >>> +        return false; >>> + >>> +    for (int i = 0; i < evsel->core.cpus->nr; i++) { >>> +        if (evsel->core.cpus->map[i] != prev->core.cpus->map[i]) >>> +            return false; >>> +    } >>> + >>> +    return true; >>> +} >>> + >>> +bool evlist__cpus_map_matched(struct evlist *evlist) >>> +{ >>> +    struct evsel *prev = evlist__first(evlist), *evsel = prev; >>> +    int nr_members = prev->core.nr_members; >>> + >>> +    evlist__for_each_entry_continue(evlist, evsel) { >>> +        if (nr_members <= 1) { >>> +            prev = evsel; >>> +            nr_members = evsel->core.nr_members; >>> +            continue; >>> +        } >>> + >>> +        nr_members--; >>> + >>> +        if (!cpus_map_matched(prev, evsel)) >>> +            return false; >>> + >>> +        prev = evsel; >>> +    } >>> + >>> +    return true; >>> +} >>> + >>> +void evlist__force_disable_group(struct evlist *evlist) >>> +{ >>> +    struct evsel *evsel; >>> + >>> +    pr_warning("WARNING: event cpu maps are not fully matched, " >>> +           "stop event grouping\n"); >>> + >>> +    evlist__for_each_entry(evlist, evsel) { >>> +        evsel->leader = evsel; >>> +        evsel->core.nr_members = 0; >>> +    } >>> +} >> >> I think this is too much, we need to disable only groups with not >> matching cpus, not all of them, how about something like this >> > > Yes, that's too much. > >> >>          struct evsel *pos; >> >>          evlist__for_each_entry(evlist, evsel) { >>                  if (evsel->leader == evsel) >>                          continue; >>                  if (!cpus_map_matched(evsel->leader, evsel)) >>                          continue; >>                  pr_warn("Disabling group... >> >>                  for_each_group_member(pos, evsel->leader) { >>                          pos->leader = pos; >>                          evsel->core.nr_members = 0; >>                  } >>          } >> >> jirka >> > > Hmm, change "!cpus_map_matched()" to "cpus_map_matched()"? and use for_each_group_evsel() to replace > for_each_group_member()? > > How about something like following? > > void evlist__check_cpu_maps(struct evlist *evlist) > { >     struct evsel *evsel, *pos; > >     evlist__for_each_entry(evlist, evsel) { >         if (evsel->leader == evsel) >             continue; > >         if (cpu_maps_matched(evsel->leader, evsel)) >             continue; > >         pr_warning("WARNING: event cpu maps are not fully matched, " >                "disable group\n"); > >         for_each_group_evsel(pos, evsel->leader) { >             pos->leader = pos; >             pos->core.nr_members = 0; >         } > >         /* >          * For core & uncore mixed event group, for example, >          * '{cycles,unc_cbo_cache_lookup.any_i}', >          * In evlist: >          * cycles, >          * unc_cbo_cache_lookup.any_i, >          * unc_cbo_cache_lookup.any_i, >          * unc_cbo_cache_lookup.any_i, >          * unc_cbo_cache_lookup.any_i, >          * >          * cycles is leader and all unc_cbo_cache_lookup.any_i >          * point to this leader. But for_each_group_evsel can't >          * iterate all members from cycles. It only iterates >          * cycles and one unc_cbo_cache_lookup.any_i. So we >          * set extra evsel here. >          */ >         evsel->leader = evsel; >         evsel->core.nr_members = 0; >     } > } > > Thanks > Jin Yao Issue is found! It looks we can't set "pos->leader = pos" in either for_each_group_member() or in for_each_group_evsel() because it may exit the iteration immediately. evlist__for_each_entry(evlist, evsel) { if (evsel->leader == evsel) continue; if (cpu_maps_matched(evsel->leader, evsel)) continue; pr_warning("WARNING: event cpu maps are not fully matched, " "disable group\n"); for_each_group_member(pos, evsel->leader) { pos->leader = pos; pos->core.nr_members = 0; } Let me use the example of '{cycles,unc_cbo_cache_lookup.any_i}' again. In evlist: cycles, unc_cbo_cache_lookup.any_i, unc_cbo_cache_lookup.any_i, unc_cbo_cache_lookup.any_i, unc_cbo_cache_lookup.any_i, When we reach the for_each_group_member at first time, evsel is the first unc_cbo_cache_lookup.any_i and evsel->leader is cycles. pos is same as the evsel (the first unc_cbo_cache_lookup.any_i). Once we execute "pos->leader = pos;", it's actually "evsel->leader = evsel". So now evsel->leader is changed to the first unc_cbo_cache_lookup.any_i. In next iteration, pos is the second unc_cbo_cache_lookup.any_i. pos->leader is cycles but unfortunately evsel->leader has been changed to the first unc_cbo_cache_lookup.any_i. So iteration stops immediately. I'm now thinking if we can solve this issue by an easy way. Thanks Jin Yao