Re: [PATCH 0/4] perf events: Add realtime clock event and timehistoption -v2

From: David Ahern
Date: Mon Feb 21 2011 - 17:09:59 EST




On 02/21/11 14:55, Frederic Weisbecker wrote:
> On Mon, Feb 21, 2011 at 02:41:53PM -0700, David Ahern wrote:
>>
>>
>> On 02/21/11 14:37, Frederic Weisbecker wrote:
>>
>>> The goal is actually to extend perf script to handle more than just raw data.
>>> So that it can handle the rest of what we can find in an event: time, ip, stacktraces...
>>>
>>> You've added 200 lines in perf report to add the dump support. It wouldn't
>>> require more to extend perf script to do that. And the result is going to be
>>> much more powerful.
>>>
>>> Look at struct scripting_ops::process_event().
>>
>> I actually have a draft of perf-script - essentially duplicating sample
>> processing done in perf-report. When it got to the point of having to
>> add a lot of code -- other features essentially -- just to get it to the
>> point of being ready for this feature I stopped.
>
>
> I don't understand why it's harder to extend print_event() rather than
> perf report.

All of the changes to perf-report are related strictly to this feature -
generating the timestamp and printing the sample including walking the
callchain.

perf-script needs to have features added to it:
1. working with all samples,
2. support for callchains,
3. more?
Then it is ready for adding a timestring to the output.

Sure it can be done, but a series of patches unrelated to timehist are
needed first.

As part of looking at perf-script (the draft I mentioned) I actually
moved most of the perf-report changes into a util/timehist.c as it is
directly usable by both commands.

David
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