Messages in this thread Patch in this message | | | Date | Fri, 13 May 2016 10:12:09 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 08/17] perf record: Don't poll on overwrite channel |
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Em Fri, May 13, 2016 at 07:56:05AM +0000, Wang Nan escreveu: > There's no need to receive events from overwritable ring buffer. Instead, > perf should make them run background until something happen. This patch > makes normal events from overwrite ring buffer ignored. > > Signed-off-by: Wang Nan <wangnan0@huawei.com> > Signed-off-by: He Kuang <hekuang@huawei.com> > Cc: Arnaldo Carvalho de Melo <acme@redhat.com> > Cc: Jiri Olsa <jolsa@kernel.org> > Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> > Cc: Namhyung Kim <namhyung@kernel.org> > Cc: Zefan Li <lizefan@huawei.com> > Cc: pi3orama@163.com > --- > tools/perf/util/evlist.c | 23 +++++++++++++++++++---- > 1 file changed, 19 insertions(+), 4 deletions(-) > > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > index abce588..f0b0457 100644 > --- a/tools/perf/util/evlist.c > +++ b/tools/perf/util/evlist.c > @@ -461,9 +461,9 @@ int perf_evlist__alloc_pollfd(struct perf_evlist *evlist) > return 0; > } > > -static int __perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd, int idx) > +static int __perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd, int idx, short revent) > { > - int pos = fdarray__add(&evlist->pollfd, fd, POLLIN | POLLERR | POLLHUP); > + int pos = fdarray__add(&evlist->pollfd, fd, revent | POLLERR | POLLHUP); > /* > * Save the idx so that when we filter out fds POLLHUP'ed we can > * close the associated evlist->mmap[] entry. > @@ -479,7 +479,7 @@ static int __perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd, int idx > > int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd) > { > - return __perf_evlist__add_pollfd(evlist, fd, -1); > + return __perf_evlist__add_pollfd(evlist, fd, -1, POLLIN); > } > > static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd) > @@ -1077,6 +1077,18 @@ perf_evlist__channel_complete(struct perf_evlist *evlist) > return 0; > } > > +static bool > +perf_evlist__should_poll(struct perf_evlist *evlist, > + struct perf_evsel *evsel, > + int channel) > +{ > + if (evsel->system_wide) > + return false;
So, what is the above doing in this patch? If we should not poll when in syswide mode, then this should be in a separate patch, unrelated to 'channels'. No?
I.e. it would be an improvement that would be cherry pickable right now, even before reviewing the channel concept.
- Arnaldo
> + if (perf_evlist__channel_check(evlist, channel, RDONLY)) > + return false; > + return true; > +} > + > static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int _idx, > struct mmap_params *mp, int cpu, > int thread, int *outputs) > @@ -1085,6 +1097,7 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int _idx, > > evlist__for_each(evlist, evsel) { > int fd, channel, idx, err; > + short revent = POLLIN; > > channel = perf_evlist__channel_find(evlist, evsel, false); > if (channel < 0) { > @@ -1114,6 +1127,8 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int _idx, > perf_evlist__mmap_get(evlist, idx); > } > > + if (!perf_evlist__should_poll(evlist, evsel, channel)) > + revent = 0; > /* > * The system_wide flag causes a selected event to be opened > * always without a pid. Consequently it will never get a > @@ -1122,7 +1137,7 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int _idx, > * Therefore don't add it for polling. > */ > if (!evsel->system_wide && > - __perf_evlist__add_pollfd(evlist, fd, idx) < 0) { > + __perf_evlist__add_pollfd(evlist, fd, idx, revent) < 0) { > perf_evlist__mmap_put(evlist, idx); > return -1; > } > -- > 1.8.3.4
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