On Fri, Feb 17, 2017 at 11:41:28AM -0300, Arnaldo Carvalho de Melo wrote: > Em Fri, Feb 17, 2017 at 03:33:27PM +0100, Jiri Olsa escreveu: > > On Fri, Feb 17, 2017 at 11:27:47AM -0300, Arnaldo Carvalho de Melo wrote: > > > Em Fri, Feb 17, 2017 at 03:00:57PM +0100, Jiri Olsa escreveu: > > > > Boris asked for default -a option in case we monitor > > > > only uncore events. While implementing that I thought > > > > it might be actually useful to make it overall default. > > > > > # perf stat > > > > Warning: No target specified, setting system-wide collection (-a). > > > > Humm, would be interesting to disable this after a few warnings? Just > > > one? > > > not sure it's good idea to keep the count of that somewhere.. > > how about i make the warning smaller ;-) > > > # perf stat > > Forced system wide target. > > ... > > > > BTW, this is how 'perf trace' works since day one, i.e. no target means > > > system wide syscall tracing. > > > or we could omit the warning completely as probably perf trace does > > I think that we should have some note on the Documentation (have you > added it?) and be done with it. > > Another thing possiblity my mind, print that at the end? like: > > perf record > ^C[ perf record: Woken up 1 times to write data - system wide samples ] > [ perf record: Captured and wrote 1.738 MB perf.data (7565 samples) ] > > ---------- > > Then people will thing, hey, so now it does systemwide samples when I > pass no target, I don't have anymore to type _three_ keys! cool! :-)
ok, posting the change with no warning jirka --- Boris asked for default -a option in case we monitor only uncore events. While implementing that I thought it might be actually useful to make it overall default. Running 'perf stat' will now collect system wide data. Requested-by: Borislav Petkov <b...@alien8.de> Signed-off-by: Jiri Olsa <jo...@kernel.org> Cc: David Ahern <dsah...@gmail.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <a.p.zijls...@chello.nl> Link: http://lkml.kernel.org/n/tip-tq11of2qlz8kxpxzva05d...@git.kernel.org --- tools/perf/Documentation/perf-stat.txt | 2 +- tools/perf/builtin-stat.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt index d96ccd4844df..aecf2a87e7d6 100644 --- a/tools/perf/Documentation/perf-stat.txt +++ b/tools/perf/Documentation/perf-stat.txt @@ -63,7 +63,7 @@ report:: -a:: --all-cpus:: - system-wide collection from all CPUs + system-wide collection from all CPUs (default if no target is specified) -c:: --scale:: diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index f28719178b51..70ed4f9d014e 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -2445,8 +2445,9 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused) } else if (big_num_opt == 0) /* User passed --no-big-num */ big_num = false; + /* Make system wide (-a) the default target. */ if (!argc && target__none(&target)) - usage_with_options(stat_usage, stat_options); + target.system_wide = true; if (run_count < 0) { pr_err("Run count must be a positive number\n"); -- 2.7.4
