Re: [PATCH 1/1] perf,tools: error out unsupported group leader immediately for perf stat

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, Jun 11, 2015 at 02:26:47PM +0000, Liang, Kan escreveu:
> > Em Thu, Jun 11, 2015 at 02:32:40AM -0400, kan.liang@intel.com escreveu:
> > > With this patch:
> > > $ perf stat -x, -e '{node-prefetch-refs,cycles}' --  sleep 1
> > > Error:
> > > The node-prefetch-refs event is not supported.

> > I get something different, maybe I am missing a patch?

> > With this patch:

> >   [acme@zoo linux]$ perf stat -x, -e '{node-prefetch-refs,cycles}' -- sleep 1
> >   Error:
> >   The sys_perf_event_open() syscall returned with 22 (Invalid argument)
> >   for event (node-prefetch-refs).
> >   /bin/dmesg may provide additional information.
> >   No CONFIG_PERF_EVENTS=y kernel support configured?

> I don't have other patches for this issue.
> It looks they have different error code, ENOENT VS. EINVAL. 
> I have no idea why. 

Well, here I have:

[acme@zoo ~]$ uname -a
Linux zoo.ghostprotocols.net 3.19.7-200.fc21.x86_64 #1 SMP Thu May 7
22:00:21 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

I am rebooting now, due to an unrelated reason, to 4.1.0-rc5+, lets see
if this explains this discrepancy...
 
> > Applying it anyway, as it avoids a core dump and the message, albeit not
> > optimal, points to a problem with that event.

> > Have you tried this with other tools, like perf record?
 
> Yes. Perf record and perf top  will error out immediately if any unsupported event found.
> So they don't have such issue.

Ok, need to revisit the event setup code again and remove the code
duplication once and for all :-\

- Arnaldo