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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 84646C11F65 for ; Wed, 30 Jun 2021 15:56:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6187A6147D for ; Wed, 30 Jun 2021 15:56:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235994AbhF3P6c (ORCPT ); Wed, 30 Jun 2021 11:58:32 -0400 Received: from mga01.intel.com ([192.55.52.88]:3979 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235978AbhF3P6a (ORCPT ); Wed, 30 Jun 2021 11:58:30 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10031"; a="230015605" X-IronPort-AV: E=Sophos;i="5.83,312,1616482800"; d="scan'208";a="230015605" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jun 2021 08:55:22 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,312,1616482800"; d="scan'208";a="559099602" Received: from nntpat99-84.inn.intel.com ([10.125.99.84]) by fmsmga001.fm.intel.com with ESMTP; 30 Jun 2021 08:55:19 -0700 From: Alexey Bayduraev To: Arnaldo Carvalho de Melo Cc: Jiri Olsa , Namhyung Kim , Alexander Shishkin , Peter Zijlstra , Ingo Molnar , linux-kernel , Andi Kleen , Adrian Hunter , Alexander Antonov , Alexei Budankov , Riccardo Mancini Subject: [PATCH v8 05/22] perf record: Start threads in the beginning of trace streaming Date: Wed, 30 Jun 2021 18:54:44 +0300 Message-Id: X-Mailer: git-send-email 2.19.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Start thread in detached state because its management is implemented via messaging to avoid any scaling issues. Block signals prior thread start so only main tool thread would be notified on external async signals during data collection. Thread affinity mask is used to assign eligible cpus for the thread to run. Wait and sync on thread start using thread ack pipe. Acked-by: Namhyung Kim Signed-off-by: Alexey Bayduraev --- tools/perf/builtin-record.c | 108 +++++++++++++++++++++++++++++++++++- 1 file changed, 107 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 82a21da2af16..cead2b3c56d7 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -1423,6 +1423,66 @@ static void record__thread_munmap_filtered(struct fdarray *fda, int fd, perf_mmap__put(map); } +static void *record__thread(void *arg) +{ + enum thread_msg msg = THREAD_MSG__READY; + bool terminate = false; + struct fdarray *pollfd; + int err, ctlfd_pos; + + thread = arg; + thread->tid = syscall(SYS_gettid); + + err = write(thread->pipes.ack[1], &msg, sizeof(msg)); + if (err == -1) + pr_err("threads[%d]: failed to notify on start: %s", thread->tid, strerror(errno)); + + pr_debug("threads[%d]: started on cpu=%d\n", thread->tid, sched_getcpu()); + + pollfd = &thread->pollfd; + ctlfd_pos = thread->ctlfd_pos; + + for (;;) { + unsigned long long hits = thread->samples; + + if (record__mmap_read_all(thread->rec, false) < 0 || terminate) + break; + + if (hits == thread->samples) { + + err = fdarray__poll(pollfd, -1); + /* + * Propagate error, only if there's any. Ignore positive + * number of returned events and interrupt error. + */ + if (err > 0 || (err < 0 && errno == EINTR)) + err = 0; + thread->waking++; + + if (fdarray__filter(pollfd, POLLERR | POLLHUP, + record__thread_munmap_filtered, NULL) == 0) + break; + } + + if (pollfd->entries[ctlfd_pos].revents & POLLHUP) { + terminate = true; + close(thread->pipes.msg[0]); + pollfd->entries[ctlfd_pos].fd = -1; + pollfd->entries[ctlfd_pos].events = 0; + } + + pollfd->entries[ctlfd_pos].revents = 0; + } + record__mmap_read_all(thread->rec, true); + + err = write(thread->pipes.ack[1], &msg, sizeof(msg)); + if (err == -1) + pr_err("threads[%d]: failed to notify on termination: %s", + thread->tid, strerror(errno)); + + return NULL; +} + static void record__init_features(struct record *rec) { struct perf_session *session = rec->session; @@ -1886,13 +1946,59 @@ static int record__terminate_thread(struct thread_data *thread_data) static int record__start_threads(struct record *rec) { + int t, tt, ret = 0, nr_threads = rec->nr_threads; struct thread_data *thread_data = rec->thread_data; + sigset_t full, mask; + pthread_t handle; + pthread_attr_t attrs; + + sigfillset(&full); + if (sigprocmask(SIG_SETMASK, &full, &mask)) { + pr_err("Failed to block signals on threads start: %s\n", strerror(errno)); + return -1; + } + + pthread_attr_init(&attrs); + pthread_attr_setdetachstate(&attrs, PTHREAD_CREATE_DETACHED); + + for (t = 1; t < nr_threads; t++) { + enum thread_msg msg = THREAD_MSG__UNDEFINED; + + pthread_attr_setaffinity_np(&attrs, + MMAP_CPU_MASK_BYTES(&(thread_data[t].mask->affinity)), + (cpu_set_t *)(thread_data[t].mask->affinity.bits)); + + if (pthread_create(&handle, &attrs, record__thread, &thread_data[t])) { + for (tt = 1; tt < t; tt++) + record__terminate_thread(&thread_data[t]); + pr_err("Failed to start threads: %s\n", strerror(errno)); + ret = -1; + goto out_err; + } + + if (read(thread_data[t].pipes.ack[0], &msg, sizeof(msg)) > 0) + pr_debug2("threads[%d]: sent %s\n", rec->thread_data[t].tid, + thread_msg_tags[msg]); + } + + if (nr_threads > 1) { + sched_setaffinity(0, MMAP_CPU_MASK_BYTES(&thread_data[0].mask->affinity), + (cpu_set_t *)thread_data[0].mask->affinity.bits); + } thread = &thread_data[0]; pr_debug("threads[%d]: started on cpu=%d\n", thread->tid, sched_getcpu()); - return 0; +out_err: + pthread_attr_destroy(&attrs); + + if (sigprocmask(SIG_SETMASK, &mask, NULL)) { + pr_err("Failed to unblock signals on threads start: %s\n", strerror(errno)); + ret = -1; + } + + return ret; } static int record__stop_threads(struct record *rec, unsigned long *waking) -- 2.19.0