| Message ID | 1463126174-119290-9-git-send-email-wangnan0@huawei.com |
|---|---|
| State | New |
| Headers | show |
On 2016/5/13 21:12, Arnaldo Carvalho de Melo wrote: > 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 think the name 'system_wide' is more or less missleading. It is not means an event in 'perf record -a', but means "a selected event to be opened always without a pid when configured by perf_evsel__config().". See bf8e8f4b8. Here we use similary logic in existing perf_evlist__mmap_per_evsel. It never poll system_wide evsel: /* * The system_wide flag causes a selected event to be opened * always without a pid. Consequently it will never get a * POLLHUP, but it is used for tracking in combination with * other events, so it should not need to be polled anyway. * Therefore don't add it for polling. */ if (!evsel->system_wide && __perf_evlist__add_pollfd(evlist, fd, idx) < 0) { perf_evlist__mmap_put(evlist, idx); return -1; } Thank you.
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; + 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; }