From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752140AbcGPUuV (ORCPT ); Sat, 16 Jul 2016 16:50:21 -0400 Received: from terminus.zytor.com ([198.137.202.10]:38856 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751693AbcGPUuR (ORCPT ); Sat, 16 Jul 2016 16:50:17 -0400 Date: Sat, 16 Jul 2016 13:50:05 -0700 From: tip-bot for Wang Nan Message-ID: Cc: hpa@zytor.com, mhiramat@kernel.org, linux-kernel@vger.kernel.org, lizefan@huawei.com, hekuang@huawei.com, tglx@linutronix.de, jolsa@kernel.org, nilayvaish@gmail.com, wangnan0@huawei.com, mingo@kernel.org, acme@redhat.com, namhyung@kernel.org Reply-To: namhyung@kernel.org, tglx@linutronix.de, wangnan0@huawei.com, jolsa@kernel.org, nilayvaish@gmail.com, mingo@kernel.org, acme@redhat.com, lizefan@huawei.com, linux-kernel@vger.kernel.org, hekuang@huawei.com, hpa@zytor.com, mhiramat@kernel.org In-Reply-To: <1468485287-33422-12-git-send-email-wangnan0@huawei.com> References: <1468485287-33422-12-git-send-email-wangnan0@huawei.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf record: Read from overwritable ring buffer Git-Commit-ID: 057374645bd42e8bcf22aa4529f99cf7c920a1c6 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 057374645bd42e8bcf22aa4529f99cf7c920a1c6 Gitweb: http://git.kernel.org/tip/057374645bd42e8bcf22aa4529f99cf7c920a1c6 Author: Wang Nan AuthorDate: Thu, 14 Jul 2016 08:34:43 +0000 Committer: Arnaldo Carvalho de Melo CommitDate: Fri, 15 Jul 2016 17:27:50 -0300 perf record: Read from overwritable ring buffer Drive the evlist->bkw_mmap_state state machine during draining and when SIGUSR2 is received. Read the backward ring buffer in record__mmap_read_all. Signed-off-by: Wang Nan Acked-by: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Nilay Vaish Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1468485287-33422-12-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index d4f15e7..b87070b 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -555,7 +555,7 @@ static int record__mmap_read_all(struct record *rec) if (err) return err; - return err; + return record__mmap_read_evlist(rec, rec->evlist, true); } static void record__init_features(struct record *rec) @@ -953,6 +953,17 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) for (;;) { unsigned long long hits = rec->samples; + /* + * rec->evlist->bkw_mmap_state is possible to be + * BKW_MMAP_EMPTY here: when done == true and + * hits != rec->samples in previous round. + * + * perf_evlist__toggle_bkw_mmap ensure we never + * convert BKW_MMAP_EMPTY to BKW_MMAP_DATA_PENDING. + */ + if (trigger_is_hit(&switch_output_trigger) || done || draining) + perf_evlist__toggle_bkw_mmap(rec->evlist, BKW_MMAP_DATA_PENDING); + if (record__mmap_read_all(rec) < 0) { trigger_error(&auxtrace_snapshot_trigger); trigger_error(&switch_output_trigger); @@ -972,8 +983,26 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) } if (trigger_is_hit(&switch_output_trigger)) { + /* + * If switch_output_trigger is hit, the data in + * overwritable ring buffer should have been collected, + * so bkw_mmap_state should be set to BKW_MMAP_EMPTY. + * + * If SIGUSR2 raise after or during record__mmap_read_all(), + * record__mmap_read_all() didn't collect data from + * overwritable ring buffer. Read again. + */ + if (rec->evlist->bkw_mmap_state == BKW_MMAP_RUNNING) + continue; trigger_ready(&switch_output_trigger); + /* + * Reenable events in overwrite ring buffer after + * record__mmap_read_all(): we should have collected + * data from it. + */ + perf_evlist__toggle_bkw_mmap(rec->evlist, BKW_MMAP_RUNNING); + if (!quiet) fprintf(stderr, "[ perf record: dump data: Woken up %ld times ]\n", waking);