From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752057AbcGNIgy (ORCPT ); Thu, 14 Jul 2016 04:36:54 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:6601 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750872AbcGNIfW (ORCPT ); Thu, 14 Jul 2016 04:35:22 -0400 From: Wang Nan To: CC: , , , Wang Nan , He Kuang , "Arnaldo Carvalho de Melo" , Jiri Olsa , "Masami Hiramatsu" , Namhyung Kim , "Nilay Vaish" Subject: [PATCH v16 11/15] perf record: Read from overwritable ring buffer Date: Thu, 14 Jul 2016 08:34:43 +0000 Message-ID: <1468485287-33422-12-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1468485287-33422-1-git-send-email-wangnan0@huawei.com> References: <1468485287-33422-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090202.57874EBD.041D,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 0557f5cad0fb1b90106ce935f69f8d95 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Drive the evlist->bkw_mmap_state state machine during draining and when SIGUSR2 is received. Read backward ring buffer in record__mmap_read_all. Signed-off-by: Wang Nan Signed-off-by: He Kuang Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: Nilay Vaish Cc: pi3orama@163.com --- 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); -- 1.8.3.4