From patchwork Wed Aug 24 15:38:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Rogers X-Patchwork-Id: 12953760 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8AE6C32796 for ; Wed, 24 Aug 2022 15:41:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239643AbiHXPln (ORCPT ); Wed, 24 Aug 2022 11:41:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239820AbiHXPlR (ORCPT ); Wed, 24 Aug 2022 11:41:17 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B490C33356 for ; Wed, 24 Aug 2022 08:41:09 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-335420c7bfeso297833887b3.16 for ; Wed, 24 Aug 2022 08:41:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc; bh=S9SBkgrIkGbpMzl2H63yon0Ve3VPPWWgZp6AvH5eWjQ=; b=shC8F2iD6aTWbO75KQwKIqPWw/jXN7AXPJirEB++poaKnZlp9J4hAgpQyRieNp84BJ LCgglHrWFR1jO3aiqxIEPZeD2JKkqLxVTvoyvmxCBZUUGrFy8DsKHEbaH0BEER1/ywK4 LdEzZqfPqAB7OgJ/oQZmfI4vVyQzBuYAh92ZSp2Dh8fVnn+rKOy6KZ4Zb29MprjfPFp7 4lnQh3ro/6OiKdjJSoTfiOM5qrA3zvzeE9SG8gbf5NFHWeijbast9Dbe4LkVVb9slqjt BP90Ka7chN3Hy/STa1xERaSRTBIptNx8SQ/fF096kTK9vh73uGMG5RSwEHx0r2kM49qu 5Ogw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc; bh=S9SBkgrIkGbpMzl2H63yon0Ve3VPPWWgZp6AvH5eWjQ=; b=cKToYzGXxOEdbFEgVTrNnQJKlW64CoEg+XYvvOgLORDo98bUKiRjxVGBNwJdInYqZf 4SEk03CEJensS5bKZLNuLnorwhXsS9j4P9iS3tgL1L4Xbj2O2fZj1hmnLxd8xVWnP48m U4u4ue26ZW/rZjbCSHzdGiXAiIvaFc3tAMzuXZQlP5wXnOW3DYzckJ1JOY1bkqYMf2CS JpCOISseX1joinflkSLm11PlHgZh63xtBN0+JiKfnLi5nxZkCmYbJs1XPYsjJMplQc5W qDCOST4urOB4NEk5Ey2xhOnidUMPkaJ+s8xvu8grY8HdtP3SXJh2oF3HoSuJnRme2hco XZLA== X-Gm-Message-State: ACgBeo0oDlAc3jb2QSuBAG5PaTjGN8F+WuD3WRySBBlKg7rZi8JLMQAy ySHHQGiQ0UrGOBoNWxpaiuRzJNFIkGyg X-Google-Smtp-Source: AA6agR53ZTPMWhd2KG9uLjlgPH1iymVadNTgHFndkrqf1nc/LpQmxU/unMIM0AspRDGfl6CbCSe/di5Zx9Fo X-Received: from irogers.svl.corp.google.com ([2620:15c:2d4:203:ab82:a348:500d:1fc4]) (user=irogers job=sendgmr) by 2002:a25:ba45:0:b0:67a:6298:7bac with SMTP id z5-20020a25ba45000000b0067a62987bacmr31638632ybj.194.1661355668775; Wed, 24 Aug 2022 08:41:08 -0700 (PDT) Date: Wed, 24 Aug 2022 08:38:59 -0700 In-Reply-To: <20220824153901.488576-1-irogers@google.com> Message-Id: <20220824153901.488576-17-irogers@google.com> Mime-Version: 1.0 References: <20220824153901.488576-1-irogers@google.com> X-Mailer: git-send-email 2.37.2.609.g9ff673ca1a-goog Subject: [PATCH v3 16/18] perf sched: Fixes for thread safety analysis From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Darren Hart , Davidlohr Bueso , " =?utf-8?q?Andr=C3=A9_Almeida?= " , Nathan Chancellor , Nick Desaulniers , Tom Rix , Weiguo Li , Athira Rajeev , Thomas Richter , Ravi Bangoria , Dario Petrillo , Hewenliang , yaowenbin , Wenyu Liu , Song Liu , Andrii Nakryiko , Dave Marchevsky , Leo Yan , Kim Phillips , Pavithra Gurushankar , Alexandre Truong , Quentin Monnet , William Cohen , Andres Freund , Adrian Hunter , " =?utf-8?q?Martin_Li=C5=A1ka?= " , Colin Ian King , James Clark , Fangrui Song , Stephane Eranian , Kajol Jain , Alexey Bayduraev , Riccardo Mancini , Andi Kleen , Masami Hiramatsu , Zechuan Chen , Jason Wang , Christophe JAILLET , Remi Bernon , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, bpf@vger.kernel.org, llvm@lists.linux.dev Cc: Ian Rogers Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add annotations to describe lock behavior. Add unlocks so that mutexes aren't conditionally held on exit from perf_sched__replay. Add an exit variable so that thread_func can terminate, rather than leaving the threads blocked on mutexes. Signed-off-by: Ian Rogers --- tools/perf/builtin-sched.c | 46 ++++++++++++++++++++++++-------------- 1 file changed, 29 insertions(+), 17 deletions(-) diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index 7e4006d6b8bc..b483ff0d432e 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -246,6 +246,7 @@ struct perf_sched { const char *time_str; struct perf_time_interval ptime; struct perf_time_interval hist_time; + volatile bool thread_funcs_exit; }; /* per thread run time data */ @@ -633,31 +634,34 @@ static void *thread_func(void *ctx) prctl(PR_SET_NAME, comm2); if (fd < 0) return NULL; -again: - ret = sem_post(&this_task->ready_for_work); - BUG_ON(ret); - mutex_lock(&sched->start_work_mutex); - mutex_unlock(&sched->start_work_mutex); - cpu_usage_0 = get_cpu_usage_nsec_self(fd); + while (!sched->thread_funcs_exit) { + ret = sem_post(&this_task->ready_for_work); + BUG_ON(ret); + mutex_lock(&sched->start_work_mutex); + mutex_unlock(&sched->start_work_mutex); - for (i = 0; i < this_task->nr_events; i++) { - this_task->curr_event = i; - perf_sched__process_event(sched, this_task->atoms[i]); - } + cpu_usage_0 = get_cpu_usage_nsec_self(fd); - cpu_usage_1 = get_cpu_usage_nsec_self(fd); - this_task->cpu_usage = cpu_usage_1 - cpu_usage_0; - ret = sem_post(&this_task->work_done_sem); - BUG_ON(ret); + for (i = 0; i < this_task->nr_events; i++) { + this_task->curr_event = i; + perf_sched__process_event(sched, this_task->atoms[i]); + } - mutex_lock(&sched->work_done_wait_mutex); - mutex_unlock(&sched->work_done_wait_mutex); + cpu_usage_1 = get_cpu_usage_nsec_self(fd); + this_task->cpu_usage = cpu_usage_1 - cpu_usage_0; + ret = sem_post(&this_task->work_done_sem); + BUG_ON(ret); - goto again; + mutex_lock(&sched->work_done_wait_mutex); + mutex_unlock(&sched->work_done_wait_mutex); + } + return NULL; } static void create_tasks(struct perf_sched *sched) + EXCLUSIVE_LOCK_FUNCTION(sched->start_work_mutex) + EXCLUSIVE_LOCK_FUNCTION(sched->work_done_wait_mutex) { struct task_desc *task; pthread_attr_t attr; @@ -687,6 +691,8 @@ static void create_tasks(struct perf_sched *sched) } static void wait_for_tasks(struct perf_sched *sched) + EXCLUSIVE_LOCKS_REQUIRED(sched->work_done_wait_mutex) + EXCLUSIVE_LOCKS_REQUIRED(sched->start_work_mutex) { u64 cpu_usage_0, cpu_usage_1; struct task_desc *task; @@ -738,6 +744,8 @@ static void wait_for_tasks(struct perf_sched *sched) } static void run_one_test(struct perf_sched *sched) + EXCLUSIVE_LOCKS_REQUIRED(sched->work_done_wait_mutex) + EXCLUSIVE_LOCKS_REQUIRED(sched->start_work_mutex) { u64 T0, T1, delta, avg_delta, fluct; @@ -3309,11 +3317,15 @@ static int perf_sched__replay(struct perf_sched *sched) print_task_traces(sched); add_cross_task_wakeups(sched); + sched->thread_funcs_exit = false; create_tasks(sched); printf("------------------------------------------------------------\n"); for (i = 0; i < sched->replay_repeat; i++) run_one_test(sched); + sched->thread_funcs_exit = true; + mutex_unlock(&sched->start_work_mutex); + mutex_unlock(&sched->work_done_wait_mutex); return 0; }