Re: [PATCH] perf: fix broken perf inject -b

[Stephane Eranian <eranian@google.com>]

Arnaldo,

On Fri, Jan 13, 2012 at 5:54 PM, Stephane Eranian <eranian@google.com> wrote:
> On Fri, Jan 13, 2012 at 5:53 PM, Arnaldo Carvalho de Melo
> <acme@redhat.com> wrote:
>> Em Fri, Jan 13, 2012 at 03:47:31PM +0100, Stephane Eranian escreveu:
>>>
>>> perf inject -b was broken. It would not inject any build_ids
>>> into the stream. Furthermore, it would strip samples from the
>>> stream.
>>
>> Against which tree is this patch?
>>
> 3.2.0-rc7-tip.
> Did that get fixed later on?
>
>>> The reason was a missing initialization of the event attribute
>>> structures. The perf_tool.tool.attr() callback was pointing to
>>> a simple repipe. But there was no initialization of internal data
>>> structures to keep track of events and event ids. That later caused
>>> event id lookups to fail, and samples would get dropped.
>>>
>>> The patch simply adds back the call to perf_event__process_attr()
>>> to initialize the evlist structure. Build_ids are again injected.
>>> The PID is also inject for PERF_RECORD_HEADER_BUILD_ID.
>>>
>>> Signed-off-by: Stephane Eranian <eranian@google.com>
>>> ---
>>>
>>> diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
>>> index 09c1061..f38f370 100644
>>> --- a/tools/perf/builtin-inject.c
>>> +++ b/tools/perf/builtin-inject.c
>>> @@ -60,6 +60,11 @@ static int perf_event__repipe_tracing_data_synth(union perf_event *event,
>>>  static int perf_event__repipe_attr(union perf_event *event,
>>>                                  struct perf_evlist **pevlist __used)
>>>  {
>>> +     int ret;
>>> +     ret = perf_event__process_attr(event, pevlist);
>>> +     if (ret)
>>> +             return ret;
>>> +
>>>       return perf_event__repipe_synth(NULL, event, NULL);
>>>  }
>>>
>>> @@ -173,6 +178,7 @@ static int perf_event__inject_buildid(struct perf_tool *tool,
>>>                      event->header.type);
>>>               goto repipe;
>>>       }
>>> +     machine->pid = event->ip.pid;
>>>
I noticed that this statement conflicts with perf buildid-list (which
I am also fixing for pipe mode).
I don't quite understand why, though.