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    SubjectRe: [PATCH -tip v3 3/6] perf branch trace: print pid and command

    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/
    >>> 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.


    > 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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