Re: [PATCH 4/5] perf stat: Add -a as a default target
From: Arnaldo Carvalho de Melo
Date: Fri Feb 17 2017 - 09:41:41 EST
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:
^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! :-)