Re: Does perf inject preserve call chain data?

[David Ahern]

On 6/8/12 11:17 AM, Tim Chen wrote:
> On Fri, 2012-06-08 at 11:13 -0600, David Ahern wrote:
> > On 6/8/12 10:44 AM, Tim Chen wrote:
> > > On Fri, 2012-06-08 at 11:38 -0300, Arnaldo Carvalho de Melo wrote:
> > > > Em Tue, May 22, 2012 at 03:58:40PM -0600, David Ahern escreveu:
> > > > > On 5/22/12 12:49 PM, Tim Chen wrote:
> > > > > > Arnaldo,
> > > > > >
> > > > > > Wonder if perf inject munged the call chain data from perf record?
> > > > > >
> > > > > > When I do
> > > > > > perf record -a -g -o - sleep 5 |perf inject -v -b  | perf report  -g -i -
> > > > > > I get a complain from perf report
> > > > > >
> > > > > > Warning:
> > > > > > Selected -g but no callchain data. Did you call 'perf record' without -g?
> > > > >
> > > > > I believe the root cause is that the event list is not written to
> > > > > the pipe. Using Arnaldo's git repo as of today (has fixes from
> > > > > Stephane) this hack shows the info is there and can be processed.
> > > >
> > > > How things stand here? Tim, did this fix things for you? If so, David,
> > > > please resend with a proper subject line and a Tested-by: Tim, ok?

Pipeline is broken by this commit in your urgent (but not yet pushed) tree:

commit 47832ad3e101e470a90fab9b4915549aaee03662
Author: Dmitry Antipov <dmitry.antipov@xxxxxxxxxx>
Date:   Fri Jun 8 16:23:27 2012 +0400

    perf report: Fix event name reporting in cross analysis

    Use trace_find_event to find event name before looking through /sys
    files. This helps 'perf report' to show real event names instead of
    'unknown:unknown' when processing perf.data recorded on another 
machine.


pevent might be NULL and pevent_find_event dereferences it causing a crash.

David
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