From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753404AbcBZJeh (ORCPT ); Fri, 26 Feb 2016 04:34:37 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:9685 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751885AbcBZJee (ORCPT ); Fri, 26 Feb 2016 04:34:34 -0500 From: Wang Nan To: Alexei Starovoitov , Arnaldo Carvalho de Melo , Arnaldo Carvalho de Melo CC: Jiri Olsa , Li Zefan , "Peter Zijlstra" , , Wang Nan , , He Kuang , Masami Hiramatsu , Namhyung Kim Subject: [PATCH 41/46] perf tools: Add API to pause a channel Date: Fri, 26 Feb 2016 09:32:29 +0000 Message-ID: <1456479154-136027-42-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1456479154-136027-1-git-send-email-wangnan0@huawei.com> References: <1456479154-136027-1-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=0001.0A090202.56D01C25.00E8,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 6d25a75b0cef376a957a7b6c26989868 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org perf_evlist__channel_toggle_paused() is introduced to pause/resume a channel in an evlist. Utilize PERF_EVENT_IOC_PAUSE_OUTPUT ioctl. Following commits use perf_evlist__channel_toggle_paused() to ensure overwrite ring buffer is turned off before reading. 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: pi3orama@163.com --- tools/perf/util/evlist.c | 28 ++++++++++++++++++++++++++++ tools/perf/util/evlist.h | 2 ++ 2 files changed, 30 insertions(+) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index c72905d..b5da393 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -706,6 +706,34 @@ int perf_evlist__channel_idx(struct perf_evlist *evlist, return 0; } +int perf_evlist__channel_toggle_paused(struct perf_evlist *evlist, + int channel, bool pause) +{ + int i; + + if (channel >= perf_evlist__channel_nr(evlist)) + return -E2BIG; + if (!evlist->mmap) + return -EFAULT; + for (i = 0; i < evlist->nr_mmaps; i++) { + int n = channel * evlist->nr_mmaps + i; + int fd = evlist->mmap[n].fd; + int err; + + if (fd < 0) + continue; + err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, + pause ? 1 : 0); + if (err) { + err = (errno == 0 ? -EINVAL : -errno); + pr_err("Unable to pause output on %d: %s\n", + fd, strerror(-err)); + return err; + } + } + return 0; +} + union perf_event *perf_evlist__mmap_read_ex(struct perf_evlist *evlist, int channel, int idx) { diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index bc6d787..c1831a9 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -180,6 +180,8 @@ perf_evlist__get_mmap(struct perf_evlist *evlist, return &evlist->mmap[idx]; } +int perf_evlist__channel_toggle_paused(struct perf_evlist *evlist, + int channel, bool pause); int perf_evlist__open(struct perf_evlist *evlist); void perf_evlist__close(struct perf_evlist *evlist); -- 1.8.3.4