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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 C0859C10F25 for ; Wed, 11 Mar 2020 05:38:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D3E721D56 for ; Wed, 11 Mar 2020 05:38:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726832AbgCKFim (ORCPT ); Wed, 11 Mar 2020 01:38:42 -0400 Received: from mga12.intel.com ([192.55.52.136]:59689 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725813AbgCKFim (ORCPT ); Wed, 11 Mar 2020 01:38:42 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Mar 2020 22:38:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,539,1574150400"; d="scan'208";a="389159058" Received: from yjin15-mobl1.ccr.corp.intel.com (HELO [10.238.4.151]) ([10.238.4.151]) by orsmga004.jf.intel.com with ESMTP; 10 Mar 2020 22:38:38 -0700 Subject: Re: [PATCH v1 02/14] perf util: Create streams for managing top N hottest callchains To: Arnaldo Carvalho de Melo Cc: 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: <20200310070245.16314-1-yao.jin@linux.intel.com> <20200310070245.16314-3-yao.jin@linux.intel.com> <20200310151117.GG15931@kernel.org> From: "Jin, Yao" Message-ID: <66542e03-e8b3-14aa-526e-ba3b59ebe076@linux.intel.com> Date: Wed, 11 Mar 2020 13:38:37 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200310151117.GG15931@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/10/2020 11:11 PM, Arnaldo Carvalho de Melo wrote: > Em Tue, Mar 10, 2020 at 03:02:33PM +0800, Jin Yao escreveu: >> We think the stream is a callchain which is aggregated by the LBR >> records from samples. By browsing the stream, we can understand >> the code flow. >> >> The struct callchain_node represents one callchain and we use the >> callchain_node->hit to measure the hot level of this callchain. >> Higher is hotter. >> >> Since in perf data file, there may be many callchains so we just >> need to focus on the top N hottest callchains. N is a user defined >> parameter or just a predefined default value. >> >> This patch saves the top N hottest callchains in 'struct stream_node' >> type array, which is defined in a per event 'struct callchain_streams'. >> >> So now we can get the per-event top N hottest callchains. >> >> Signed-off-by: Jin Yao >> --- >> tools/perf/util/callchain.c | 125 ++++++++++++++++++++++++++++++++++++ >> tools/perf/util/callchain.h | 16 +++++ >> 2 files changed, 141 insertions(+) >> >> diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c >> index 818aa4efd386..d9c68a8e7619 100644 >> --- a/tools/perf/util/callchain.c >> +++ b/tools/perf/util/callchain.c >> @@ -31,6 +31,7 @@ >> #include "callchain.h" >> #include "branch.h" >> #include "symbol.h" >> +#include "evlist.h" >> #include "../perf.h" >> >> #define CALLCHAIN_PARAM_DEFAULT \ >> @@ -1599,3 +1600,127 @@ void callchain_cursor_reset(struct callchain_cursor *cursor) >> for (node = cursor->first; node != NULL; node = node->next) >> map__zput(node->ms.map); >> } >> + >> +static void free_evsel_streams(struct callchain_streams *callchain_streams, >> + int nr_evsel) >> +{ >> + for (int i = 0; i < nr_evsel; i++) { >> + if (callchain_streams[i].streams) >> + free(callchain_streams[i].streams); > > free(NULL) is valid, so remove that extra check and use zfree() to reset > that entry to NULL, i.e.: > > for () > zfree(&callchain_streams[i].streams); > Yes, will use zfree() here. >> + } >> + >> + free(callchain_streams); >> +} >> + >> +static struct callchain_streams *create_evsel_streams(int nr_evsel, >> + int nr_streams_max) >> +{ >> + struct callchain_streams *callchain_streams; >> + >> + callchain_streams = calloc(nr_evsel, sizeof(struct callchain_streams)); > > calloc is the right thing here, as this is an array > Yes. If just allocation for one element, I should use zalloc(). Thanks Jin Yao >> + if (!callchain_streams) >> + return NULL; >> + >> + for (int i = 0; i < nr_evsel; i++) { >> + struct callchain_streams *s = &callchain_streams[i]; >> + >> + s->streams = calloc(nr_streams_max, sizeof(struct stream_node)); >> + if (!s->streams) >> + goto err; >> + >> + s->nr_streams_max = nr_streams_max; >> + s->evsel_idx = -1; >> + } >> + >> + return callchain_streams; >> + >> +err: >> + free_evsel_streams(callchain_streams, nr_evsel); >> + return NULL; >> +} >> + >> +/* >> + * The cnodes with high hit number are hot callchains. >> + */ >> +static void set_hot_cnode(struct callchain_streams *s, >> + struct callchain_node *cnode) >> +{ >> + int i, idx = 0; >> + u64 hit; >> + >> + if (s->nr_streams < s->nr_streams_max) { >> + i = s->nr_streams; >> + s->streams[i].cnode = cnode; >> + s->nr_streams++; >> + return; >> + } >> + >> + /* >> + * Since only a few number of hot streams, so only use simple >> + * way to find the cnode with smallest hit number and replace. >> + */ >> + hit = (s->streams[0].cnode)->hit; >> + for (i = 1; i < s->nr_streams; i++) { >> + if ((s->streams[i].cnode)->hit < hit) { >> + hit = (s->streams[i].cnode)->hit; >> + idx = i; >> + } >> + } >> + >> + if (cnode->hit > hit) >> + s->streams[idx].cnode = cnode; >> +} >> + >> +static void update_hot_streams(struct hist_entry *he, >> + struct callchain_streams *s) >> +{ >> + struct rb_root *root = &he->sorted_chain; >> + struct rb_node *rb_node = rb_first(root); >> + struct callchain_node *node; >> + >> + while (rb_node) { >> + node = rb_entry(rb_node, struct callchain_node, rb_node); >> + set_hot_cnode(s, node); >> + rb_node = rb_next(rb_node); >> + } >> +} >> + >> +static void get_hot_streams(struct hists *hists, >> + struct callchain_streams *s) >> +{ >> + struct rb_node *next; >> + >> + next = rb_first_cached(&hists->entries); >> + while (next) { >> + struct hist_entry *he; >> + >> + he = rb_entry(next, struct hist_entry, rb_node); >> + update_hot_streams(he, s); >> + next = rb_next(&he->rb_node); >> + } >> +} >> + >> +struct callchain_streams *callchain_evsel_streams_create(struct evlist *evlist, >> + int nr_streams_max, >> + int *nr_evsel_streams) >> +{ >> + int nr_evsel = evlist->core.nr_entries, i = 0; >> + struct callchain_streams *callchain_streams; >> + struct evsel *pos; >> + >> + callchain_streams = create_evsel_streams(nr_evsel, nr_streams_max); >> + if (!callchain_streams) >> + return NULL; >> + >> + evlist__for_each_entry(evlist, pos) { >> + struct hists *hists = evsel__hists(pos); >> + >> + hists__output_resort(hists, NULL); >> + get_hot_streams(hists, &callchain_streams[i]); >> + callchain_streams[i].evsel_idx = pos->idx; >> + i++; >> + } >> + >> + *nr_evsel_streams = nr_evsel; >> + return callchain_streams; >> +} >> diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h >> index 706bb7bbe1e1..5852990cdf60 100644 >> --- a/tools/perf/util/callchain.h >> +++ b/tools/perf/util/callchain.h >> @@ -13,6 +13,7 @@ struct ip_callchain; >> struct map; >> struct perf_sample; >> struct thread; >> +struct evlist; >> >> #define HELP_PAD "\t\t\t\t" >> >> @@ -159,6 +160,17 @@ struct callchain_cursor { >> struct callchain_cursor_node *curr; >> }; >> >> +struct stream_node { >> + struct callchain_node *cnode; >> +}; >> + >> +struct callchain_streams { >> + struct stream_node *streams; >> + int nr_streams_max; >> + int nr_streams; >> + int evsel_idx; >> +}; >> + >> extern __thread struct callchain_cursor callchain_cursor; >> >> static inline void callchain_init(struct callchain_root *root) >> @@ -289,4 +301,8 @@ int callchain_branch_counts(struct callchain_root *root, >> u64 *branch_count, u64 *predicted_count, >> u64 *abort_count, u64 *cycles_count); >> >> +struct callchain_streams *callchain_evsel_streams_create(struct evlist *evlist, >> + int nr_streams_max, >> + int *nr_evsel_streams); >> + >> #endif /* __PERF_CALLCHAIN_H */ >> -- >> 2.17.1 >> >