Messages in this thread | | | Date | Fri, 01 Apr 2011 11:11:10 -0600 | From | David Ahern <> | Subject | Re: [PATCH -tip v3 3/6] perf branch trace: print pid and command |
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On 04/01/11 09:13, Frederic Weisbecker wrote: > On Mon, Mar 28, 2011 at 08:31:23AM -0600, David Ahern wrote: >> On 03/28/11 04:34, Akihiro Nagai wrote: >>>> from is sample->ip? to is sample->addr? In the above example >>>> 0x39d3015260 is the value from sample->addr, 1526f is sample->ip which >>>> resolves to _dl_next_ld_env_entry from /lib64/ld-2.13.so. >>> Yes. >>> In this example, resolved address is only sample->ip (branch from). >>> We need the resolved address of sample->addr (branch to) too, because >>> both of them are addresses of execution code. >> >> Ok, now I understand. In that case add conversion of sample->addr to >> symbols to perf-script. > > I agree that we should rather use perf script for branch dumps. > Sorry Akihiro, I think we suggested you to create this dedicated > perf branch by the past. But then perf script became the vanilla dump > tool in the middle and it seems more suitable today. > > We can still create a perf branch later in order to produce some more > advanced post-processing tools. But for sample dumps perf script (which starts > to show itself as a misnomer BTW) seems to be the right place.
perf-dump?
> > So, in this context, if we have PERF_SAMPLE_ADDR, we are going to always > follow the ip with a "=>" and then resolve the address, etc... > > Yeah it makes sense for this default mode. But what about when we'll want > a function graph kind of output? This will require a totally different > layout. Also PERF_SAMPLE_ADDR may be used for different context in the > future. > > Perhaps we want a kind of per evsel callback that makes its own > interpretation of the pid/tid/dso/sym/etc... options asked by the > user?
The print addr function can take the evsel as an input. It includes the event type which can be used to decide what the address means.
> > But well, we can start simple and make and just do the => trick > if we have PERF_SAMPLE_ADDR and resolve addr if the user asked > the sym. Then when we have the graph output, have these per evsel > display callbacks.
There is another email thread about page faults. The user wants sample address resolved to symbols. I was going to look into it next week when I get back from vacation.
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