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=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 BC8F0C43381 for ; Fri, 22 Mar 2019 22:45:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79B4E2075E for ; Fri, 22 Mar 2019 22:45:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728522AbfCVWpq (ORCPT ); Fri, 22 Mar 2019 18:45:46 -0400 Received: from terminus.zytor.com ([198.137.202.136]:36385 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728436AbfCVWpn (ORCPT ); Fri, 22 Mar 2019 18:45:43 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x2MMjAEZ757846 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Fri, 22 Mar 2019 15:45:10 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x2MMj9GV757843; Fri, 22 Mar 2019 15:45:09 -0700 Date: Fri, 22 Mar 2019 15:45:09 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Song Liu Message-ID: Cc: jolsa@kernel.org, sdf@google.com, hpa@zytor.com, acme@redhat.com, songliubraving@fb.com, mingo@kernel.org, peterz@infradead.org, linux-kernel@vger.kernel.org, daniel@iogearbox.net, ast@kernel.org, namhyung@kernel.org, tglx@linutronix.de Reply-To: linux-kernel@vger.kernel.org, tglx@linutronix.de, daniel@iogearbox.net, ast@kernel.org, namhyung@kernel.org, hpa@zytor.com, mingo@kernel.org, songliubraving@fb.com, acme@redhat.com, sdf@google.com, jolsa@kernel.org, peterz@infradead.org In-Reply-To: <20190312053051.2690567-15-songliubraving@fb.com> References: <20190312053051.2690567-15-songliubraving@fb.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf evlist: Introduce side band thread Git-Commit-ID: 657ee5531903339b06697581532ed32d4762526e X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 657ee5531903339b06697581532ed32d4762526e Gitweb: https://git.kernel.org/tip/657ee5531903339b06697581532ed32d4762526e Author: Song Liu AuthorDate: Mon, 11 Mar 2019 22:30:50 -0700 Committer: Arnaldo Carvalho de Melo CommitDate: Thu, 21 Mar 2019 11:27:03 -0300 perf evlist: Introduce side band thread This patch introduces side band thread that captures extended information for events like PERF_RECORD_BPF_EVENT. This new thread uses its own evlist that uses ring buffer with very low watermark for lower latency. To use side band thread, we need to: 1. add side band event(s) by calling perf_evlist__add_sb_event(); 2. calls perf_evlist__start_sb_thread(); 3. at the end of perf run, perf_evlist__stop_sb_thread(). In the next patch, we use this thread to handle PERF_RECORD_BPF_EVENT. Committer notes: Add fix by Jiri Olsa for when te sb_tread can't get started and then at the end the stop_sb_thread() segfaults when joining the (non-existing) thread. That can happen when running 'perf top' or 'perf record' as a normal user, for instance. Further checks need to be done on top of this to more graciously handle these possible failure scenarios. Signed-off-by: Song Liu Reviewed-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stanislav Fomichev Link: http://lkml.kernel.org/r/20190312053051.2690567-15-songliubraving@fb.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 9 ++++ tools/perf/builtin-top.c | 9 ++++ tools/perf/util/evlist.c | 119 ++++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/evlist.h | 12 +++++ tools/perf/util/evsel.h | 6 +++ 5 files changed, 155 insertions(+) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index e79faccd7842..6f645fd72fed 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -1137,6 +1137,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) struct perf_data *data = &rec->data; struct perf_session *session; bool disabled = false, draining = false; + struct perf_evlist *sb_evlist = NULL; int fd; atexit(record__sig_exit); @@ -1237,6 +1238,11 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) goto out_child; } + if (perf_evlist__start_sb_thread(sb_evlist, &rec->opts.target)) { + pr_debug("Couldn't start the BPF side band thread:\nBPF programs starting from now on won't be annotatable\n"); + opts->no_bpf_event = true; + } + err = record__synthesize(rec, false); if (err < 0) goto out_child; @@ -1487,6 +1493,9 @@ out_child: out_delete_session: perf_session__delete(session); + + if (!opts->no_bpf_event) + perf_evlist__stop_sb_thread(sb_evlist); return status; } diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index c2ea22c4ea67..3ce8a8db6c1d 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -1501,6 +1501,7 @@ int cmd_top(int argc, const char **argv) "number of thread to run event synthesize"), OPT_END() }; + struct perf_evlist *sb_evlist = NULL; const char * const top_usage[] = { "perf top []", NULL @@ -1636,8 +1637,16 @@ int cmd_top(int argc, const char **argv) goto out_delete_evlist; } + if (perf_evlist__start_sb_thread(sb_evlist, target)) { + pr_debug("Couldn't start the BPF side band thread:\nBPF programs starting from now on won't be annotatable\n"); + opts->no_bpf_event = true; + } + status = __cmd_top(&top); + if (!opts->no_bpf_event) + perf_evlist__stop_sb_thread(sb_evlist); + out_delete_evlist: perf_evlist__delete(top.evlist); perf_session__delete(top.session); diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index ed20f4379956..ec78e93085de 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -19,6 +19,7 @@ #include "debug.h" #include "units.h" #include "asm/bug.h" +#include "bpf-event.h" #include #include @@ -1856,3 +1857,121 @@ struct perf_evsel *perf_evlist__reset_weak_group(struct perf_evlist *evsel_list, } return leader; } + +int perf_evlist__add_sb_event(struct perf_evlist **evlist, + struct perf_event_attr *attr, + perf_evsel__sb_cb_t cb, + void *data) +{ + struct perf_evsel *evsel; + bool new_evlist = (*evlist) == NULL; + + if (*evlist == NULL) + *evlist = perf_evlist__new(); + if (*evlist == NULL) + return -1; + + if (!attr->sample_id_all) { + pr_warning("enabling sample_id_all for all side band events\n"); + attr->sample_id_all = 1; + } + + evsel = perf_evsel__new_idx(attr, (*evlist)->nr_entries); + if (!evsel) + goto out_err; + + evsel->side_band.cb = cb; + evsel->side_band.data = data; + perf_evlist__add(*evlist, evsel); + return 0; + +out_err: + if (new_evlist) { + perf_evlist__delete(*evlist); + *evlist = NULL; + } + return -1; +} + +static void *perf_evlist__poll_thread(void *arg) +{ + struct perf_evlist *evlist = arg; + bool draining = false; + int i; + + while (draining || !(evlist->thread.done)) { + if (draining) + draining = false; + else if (evlist->thread.done) + draining = true; + + if (!draining) + perf_evlist__poll(evlist, 1000); + + for (i = 0; i < evlist->nr_mmaps; i++) { + struct perf_mmap *map = &evlist->mmap[i]; + union perf_event *event; + + if (perf_mmap__read_init(map)) + continue; + while ((event = perf_mmap__read_event(map)) != NULL) { + struct perf_evsel *evsel = perf_evlist__event2evsel(evlist, event); + + if (evsel && evsel->side_band.cb) + evsel->side_band.cb(event, evsel->side_band.data); + else + pr_warning("cannot locate proper evsel for the side band event\n"); + + perf_mmap__consume(map); + } + perf_mmap__read_done(map); + } + } + return NULL; +} + +int perf_evlist__start_sb_thread(struct perf_evlist *evlist, + struct target *target) +{ + struct perf_evsel *counter; + + if (!evlist) + return 0; + + if (perf_evlist__create_maps(evlist, target)) + goto out_delete_evlist; + + evlist__for_each_entry(evlist, counter) { + if (perf_evsel__open(counter, evlist->cpus, + evlist->threads) < 0) + goto out_delete_evlist; + } + + if (perf_evlist__mmap(evlist, UINT_MAX)) + goto out_delete_evlist; + + evlist__for_each_entry(evlist, counter) { + if (perf_evsel__enable(counter)) + goto out_delete_evlist; + } + + evlist->thread.done = 0; + if (pthread_create(&evlist->thread.th, NULL, perf_evlist__poll_thread, evlist)) + goto out_delete_evlist; + + return 0; + +out_delete_evlist: + perf_evlist__delete(evlist); + evlist = NULL; + return -1; +} + +void perf_evlist__stop_sb_thread(struct perf_evlist *evlist) +{ + if (!evlist) + return; + evlist->thread.done = 1; + pthread_join(evlist->thread.th, NULL); + perf_evlist__delete(evlist); +} diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 744906dd4887..dcb68f34d2cd 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -54,6 +54,10 @@ struct perf_evlist { struct perf_sample *sample); u64 first_sample_time; u64 last_sample_time; + struct { + pthread_t th; + volatile int done; + } thread; }; struct perf_evsel_str_handler { @@ -87,6 +91,14 @@ int __perf_evlist__add_default_attrs(struct perf_evlist *evlist, int perf_evlist__add_dummy(struct perf_evlist *evlist); +int perf_evlist__add_sb_event(struct perf_evlist **evlist, + struct perf_event_attr *attr, + perf_evsel__sb_cb_t cb, + void *data); +int perf_evlist__start_sb_thread(struct perf_evlist *evlist, + struct target *target); +void perf_evlist__stop_sb_thread(struct perf_evlist *evlist); + int perf_evlist__add_newtp(struct perf_evlist *evlist, const char *sys, const char *name, void *handler); diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index cc578e02e08f..0f2c6c93d721 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -73,6 +73,8 @@ struct perf_evsel_config_term { struct perf_stat_evsel; +typedef int (perf_evsel__sb_cb_t)(union perf_event *event, void *data); + /** struct perf_evsel - event selector * * @evlist - evlist this evsel is in, if it is in one. @@ -151,6 +153,10 @@ struct perf_evsel { bool collect_stat; bool weak_group; const char *pmu_name; + struct { + perf_evsel__sb_cb_t *cb; + void *data; + } side_band; }; union u64_swap {