Re: [PATCH 02/25] perf stat record: Add record command

Jiri Olsa
2015-11-06T14:13:34Z

On Fri, Nov 06, 2015 at 10:33:03AM -0300, Arnaldo Carvalho de Melo wrote:

SNIP

>
> Humm, no, there are several things we should strive for, and
> bisectability is one of the first, it requires smaller, self contained
> patches, sure, but it also requires that at after applying each patch we
> have sane output from the tools.
>
> So, after applying the patch above we get a message that says the file
> is corrupted, and more than that, it even forgets to put a newline,
> further breaking the output.

well, because the 'perf stat record' creates just minimal
perf.data and I'm adding data itself in later commits

>
> > [PATCH 02/25] perf stat record: Add record command
> > - adds record command that creates empty perf.data
> >
> > [PATCH 03/25] perf stat record: Initialize record features
> > - adds FEATURES initialization for stat data
> >
> > [PATCH 04/25] perf stat record: Synthesize stat record data
> > - adds meta data
> >
> > [PATCH 05/25] perf stat record: Store events IDs in perf data file
> > - adds event IDs
> > ...
> >
> >
> > you get proper warning right after patch 3/25, where
> > we store STAT feature bit and properly check it when
> > opening perf.data
>
> But that will be will _new_ tools, right? I'm talking about getting sane
> output from _older_, unmodified, tools, like I demonstrated.

new and old.. there's change to react on STAT feature
during opening perf data file in 03/25 that fixes the
issue.. I moved it from 'report' command patch earlier
in the patchset

jirka