From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751263AbcETSFO (ORCPT ); Fri, 20 May 2016 14:05:14 -0400 Received: from mail.kernel.org ([198.145.29.136]:51663 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750759AbcETSFN (ORCPT ); Fri, 20 May 2016 14:05:13 -0400 Date: Fri, 20 May 2016 15:05:07 -0300 From: Arnaldo Carvalho de Melo To: Wang Nan Cc: pi3orama@163.com, linux-kernel@vger.kernel.org, He Kuang , Arnaldo Carvalho de Melo , Jiri Olsa , Masami Hiramatsu , Namhyung Kim , Zefan Li Subject: Re: [PATCH v2 03/13] perf tools: Add API to pause a evlist Message-ID: <20160520180507.GC8897@kernel.org> References: <1463762315-155689-1-git-send-email-wangnan0@huawei.com> <1463762315-155689-4-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1463762315-155689-4-git-send-email-wangnan0@huawei.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, May 20, 2016 at 04:38:25PM +0000, Wang Nan escreveu: > perf_evlist__toggle_paused() is introduced to pause/resume events > in an evlist. Utilize PERF_EVENT_IOC_PAUSE_OUTPUT ioctl. Following > commits use perf_evlist__toggle_paused() to ensure overwrite > ring buffer is paused before reading. > +{ int perf_evlist__toggle_paused(struct perf_evlist *evlist, bool pause) Humm, toggle means, 1 -> 0 or 0 -> 1, not set(n), i.e. you either call this: int perf_evlist__toggle_paused(struct perf_evlist *evlist) and keep an evsel->paused that starts with false and then you, in this function, use: err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, evsel->pause ? 1 : 0); if (!err) evsel->paused = !evsel->paused; Or: int perf_evlist__set_paused(struct perf_evlist *evlist, bool pause) and do as you did below. And you could do, to make it shorter, more intuitive: static inline int perf_evlist__pause(struct perf_evlist *evlist) { return perf_evlist__set_paused(evlist, true); } static inline int perf_evlist__continue(struct perf_evlist *evlist) { return perf_evlist__set_paused(evlist, false); } I applied the first two patches. - Arnaldo > 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 | 22 ++++++++++++++++++++++ > tools/perf/util/evlist.h | 1 + > 2 files changed, 23 insertions(+) > > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > index 1a370db..f4bb8be 100644 > --- a/tools/perf/util/evlist.c > +++ b/tools/perf/util/evlist.c > @@ -679,6 +679,28 @@ static struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist, > return NULL; > } > > +int perf_evlist__toggle_paused(struct perf_evlist *evlist, bool pause) > +{ > + int i; > + > + for (i = 0; i < evlist->nr_mmaps; i++) { > + int fd = evlist->mmap[i].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; > +} > + > /* When check_messup is true, 'end' must points to a good entry */ > static union perf_event * > perf_mmap__read(struct perf_mmap *md, bool check_messup, u64 start, > diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h > index 0d165b1..13234dc 100644 > --- a/tools/perf/util/evlist.h > +++ b/tools/perf/util/evlist.h > @@ -136,6 +136,7 @@ void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx); > > void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx); > > +int perf_evlist__toggle_paused(struct perf_evlist *evlist, bool pause); > int perf_evlist__open(struct perf_evlist *evlist); > void perf_evlist__close(struct perf_evlist *evlist); > > -- > 1.8.3.4