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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 E9F17C433E0 for ; Fri, 12 Mar 2021 03:25:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B40EF64F8D for ; Fri, 12 Mar 2021 03:25:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231600AbhCLDYg (ORCPT ); Thu, 11 Mar 2021 22:24:36 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:13503 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231573AbhCLDYK (ORCPT ); Thu, 11 Mar 2021 22:24:10 -0500 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4DxWMb4PTHzrVGW; Fri, 12 Mar 2021 11:22:19 +0800 (CST) Received: from [10.67.102.248] (10.67.102.248) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.498.0; Fri, 12 Mar 2021 11:24:00 +0800 Subject: Re: [PATCH] perf annotate: Fix sample events lost in stdio mode To: Namhyung Kim CC: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Yao Jin , , , linux-kernel , References: <20210306082859.179541-1-yangjihong1@huawei.com> <53ff575f-1fcf-6650-76ad-a0304f6bdf15@huawei.com> From: Yang Jihong Message-ID: <02146240-e532-1c52-0589-bfff3fbe5166@huawei.com> Date: Fri, 12 Mar 2021 11:24:00 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.102.248] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Namhyung On 2021/3/11 22:42, Namhyung Kim wrote: > Hi, > > On Thu, Mar 11, 2021 at 5:48 PM Yang Jihong wrote: >> >> Hello, >> >> On 2021/3/6 16:28, Yang Jihong wrote: >>> In hist__find_annotations function, since have a hist_entry per IP for the same >>> symbol, we free notes->src to signal already processed this symbol in stdio mode; >>> when annotate, entry will skipped if notes->src is NULL to avoid repeated output. > > I'm not sure it's still true that we have a hist_entry per IP. > Afaik the default sort key is comm,dso,sym which means it should have a single > hist_entry for each symbol. It seems like an old comment.. > Emm, yes, we have a hist_entry for per IP. a member named "sym" in struct "hist_entry" points to symbol, different IP may point to the same symbol. The hist_entry struct is as follows: struct hist_entry { ... struct map_symbol ms; ... }; struct map_symbol { struct maps *maps; struct map *map; struct symbol *sym; }; >>> >>> However, there is a problem, for example, run the following command: >>> >>> # perf record -e branch-misses -e branch-instructions -a sleep 1 >>> >>> perf.data file contains different types of sample event. >>> >>> If the same IP sample event exists in branch-misses and branch-instructions, >>> this event uses the same symbol. When annotate branch-misses events, notes->src >>> corresponding to this event is set to null, as a result, when annotate >>> branch-instructions events, this event is skipped and no annotate is output. >>> >>> Solution of this patch is to add a u8 member to struct sym_hist and use a bit to >>> indicate whether the symbol has been processed. >>> Because different types of event correspond to different sym_hist, no conflict >>> occurs. >>> --- >>> tools/perf/builtin-annotate.c | 22 ++++++++++++++-------- >>> tools/perf/util/annotate.h | 4 ++++ >>> 2 files changed, 18 insertions(+), 8 deletions(-) >>> >>> diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c >>> index a23ba6bb99b6..c8c67892ae82 100644 >>> --- a/tools/perf/builtin-annotate.c >>> +++ b/tools/perf/builtin-annotate.c >>> @@ -372,15 +372,21 @@ static void hists__find_annotations(struct hists *hists, >>> if (next != NULL) >>> nd = next; >>> } else { >>> - hist_entry__tty_annotate(he, evsel, ann); >>> + struct sym_hist *h = annotated_source__histogram(notes->src, >>> + evsel->idx); >>> + >>> + if (h->processed == 0) { >>> + hist_entry__tty_annotate(he, evsel, ann); >>> + >>> + /* >>> + * Since we have a hist_entry per IP for the same >>> + * symbol, set processed flag of evsel in sym_hist >>> + * to signal we already processed this symbol. >>> + */ >>> + h->processed = 1; >>> + } >>> + >>> nd = rb_next(nd); >>> - /* >>> - * Since we have a hist_entry per IP for the same >>> - * symbol, free he->ms.sym->src to signal we already >>> - * processed this symbol. >>> - */ >>> - zfree(¬es->src->cycles_hist); >>> - zfree(¬es->src); >>> } >>> } >>> } >>> diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h >>> index 096cdaf21b01..89872bfdc958 100644 >>> --- a/tools/perf/util/annotate.h >>> +++ b/tools/perf/util/annotate.h >>> @@ -228,6 +228,10 @@ void symbol__calc_percent(struct symbol *sym, struct evsel *evsel); >>> struct sym_hist { >>> u64 nr_samples; >>> u64 period; >>> + >>> + u8 processed : 1, /* whether symbol has been processed, used for annotate */ >>> + __reserved : 7; > > I think just a bool member is fine. > OK, I have submitted the v2 patch and changed to bool member, new patch is as follows, look forward to your review: https://lore.kernel.org/patchwork/patch/1393901/ >>> + >>> struct sym_hist_entry addr[]; >>> }; >>> >>> >> Please check whether this solution is feasible, look forward to your review. > > What about this? (not tested) > > diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c > index a23ba6bb99b6..a91fe45bd69f 100644 > --- a/tools/perf/builtin-annotate.c > +++ b/tools/perf/builtin-annotate.c > @@ -374,13 +374,6 @@ static void hists__find_annotations(struct hists *hists, > } else { > hist_entry__tty_annotate(he, evsel, ann); > nd = rb_next(nd); > - /* > - * Since we have a hist_entry per IP for the same > - * symbol, free he->ms.sym->src to signal we already > - * processed this symbol. > - */ > - zfree(¬es->src->cycles_hist); > - zfree(¬es->src); > } > } > } > This solution may have the following problem: For example, if two sample events are in two different processes but in the same symbol, repeated output may occur. Therefore, a flag is required to indicate whether the symbol has been processed to avoid repeated output. > Thanks, > Namhyung > . > Thanks, Yang .