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Date: Tue, 24 May 2016 15:10:52 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Adrian Hunter <adrian.hunter@...el.com>
Cc: Andi Kleen <andi@...stfloor.org>, jolsa@...nel.org,
linux-kernel@...r.kernel.org, Andi Kleen <ak@...ux.intel.com>
Subject: Re: [PATCH 1/3] perf pt: Mark PT return events as "return"
Em Tue, May 24, 2016 at 07:26:19PM +0300, Adrian Hunter escreveu:
> On 24/05/2016 5:57 p.m., Arnaldo Carvalho de Melo wrote:
> > Em Mon, May 23, 2016 at 05:52:23PM -0700, Andi Kleen escreveu:
> > > From: Andi Kleen <ak@...ux.intel.com>
> > >
> > > With perf script --itrace=cr we can synthesize calls and returns out of
> > > a PT log. However both calls and returns are marked with the same event,
> > > called branches. This makes it difficult to read and post process,
> > > because calls and returns are somewhat diffferent.
> > >
> > > Create a separate return event and mark the returns as return.
> >
> > Adrian, you voiced some concerns about this patch, are those settled?
>
> What about beautifying the sample flags i.e. instead of displaying the
> letters interpret them into something more human readable e.g.
Looks like a good idea, but can't this be done on top of what he sent?
- Arnaldo
> bc call
> br return
> bo conditional jump
> b jump
> bci software interrupt
> bri return from interrupt
> bcs system call
> brs return from system call
> by asynchronous branch
> bcyi hardware interrupt
> bA transaction abort
> bB trace begin
> bE trace end
>
> In Tx (x) can turn up on a number of those too.
>
>
> > Can I have your Acked-by, please?
> >
> > - Arnaldo
> >
> > > Cc: adrian.hunter@...el.com
> > > Signed-off-by: Andi Kleen <ak@...ux.intel.com>
> > > ---
> > > tools/perf/util/intel-pt.c | 53 +++++++++++++++++++++++++++++++++++++++++-----
> > > 1 file changed, 48 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
> > > index 137196990012..4f0b1d7adf50 100644
> > > --- a/tools/perf/util/intel-pt.c
> > > +++ b/tools/perf/util/intel-pt.c
> > > @@ -82,9 +82,12 @@ struct intel_pt {
> > > u64 instructions_id;
> > >
> > > bool sample_branches;
> > > + bool sample_returns;
> > > u32 branches_filter;
> > > u64 branches_sample_type;
> > > + u64 returns_sample_type;
> > > u64 branches_id;
> > > + u64 returns_id;
> > >
> > > bool sample_transactions;
> > > u64 transactions_sample_type;
> > > @@ -960,7 +963,8 @@ static int intel_pt_inject_event(union perf_event *event,
> > > return perf_event__synthesize_sample(event, type, 0, sample, swapped);
> > > }
> > >
> > > -static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq)
> > > +static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq,
> > > + bool is_return)
> > > {
> > > int ret;
> > > struct intel_pt *pt = ptq->pt;
> > > @@ -990,8 +994,13 @@ static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq)
> > > sample.pid = ptq->pid;
> > > sample.tid = ptq->tid;
> > > sample.addr = ptq->state->to_ip;
> > > - sample.id = ptq->pt->branches_id;
> > > - sample.stream_id = ptq->pt->branches_id;
> > > + if (is_return) {
> > > + sample.id = ptq->pt->returns_id;
> > > + sample.stream_id = ptq->pt->returns_id;
> > > + } else {
> > > + sample.id = ptq->pt->branches_id;
> > > + sample.stream_id = ptq->pt->branches_id;
> > > + }
> > > sample.period = 1;
> > > sample.cpu = ptq->cpu;
> > > sample.flags = ptq->flags;
> > > @@ -1014,6 +1023,8 @@ static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq)
> > >
> > > if (pt->synth_opts.inject) {
> > > ret = intel_pt_inject_event(event, &sample,
> > > + is_return ?
> > > + pt->returns_sample_type :
> > > pt->branches_sample_type,
> > > pt->synth_needs_swap);
> > > if (ret)
> > > @@ -1241,7 +1252,13 @@ static int intel_pt_sample(struct intel_pt_queue *ptq)
> > > thread_stack__set_trace_nr(ptq->thread, state->trace_nr);
> > >
> > > if (pt->sample_branches) {
> > > - err = intel_pt_synth_branch_sample(ptq);
> > > + err = intel_pt_synth_branch_sample(ptq, false);
> > > + if (err)
> > > + return err;
> > > + }
> > > +
> > > + if (pt->sample_returns) {
> > > + err = intel_pt_synth_branch_sample(ptq, true);
> > > if (err)
> > > return err;
> > > }
> > > @@ -1956,7 +1973,33 @@ static int intel_pt_synth_events(struct intel_pt *pt,
> > > }
> > > pt->sample_branches = true;
> > > pt->branches_sample_type = attr.sample_type;
> > > - pt->branches_id = id;
> > > + pt->branches_id = id++;
> > > + }
> > > + if (pt->synth_opts.returns) {
> > > + attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS;
> > > + attr.sample_period = 1;
> > > + attr.sample_type |= PERF_SAMPLE_ADDR;
> > > + attr.sample_type &= ~(u64)PERF_SAMPLE_CALLCHAIN;
> > > + attr.sample_type &= ~(u64)PERF_SAMPLE_BRANCH_STACK;
> > > + pr_debug("Synthesizing 'return' event with id %" PRIu64 " sample type %#" PRIx64 "\n",
> > > + id, (u64)attr.sample_type);
> > > + err = intel_pt_synth_event(session, &attr, id);
> > > + if (err) {
> > > + pr_err("%s: failed to synthesize 'return' event type\n",
> > > + __func__);
> > > + return err;
> > > + }
> > > + pt->sample_returns = true;
> > > + pt->returns_sample_type = attr.sample_type;
> > > + pt->returns_id = id;
> > > + evlist__for_each(evlist, evsel) {
> > > + if (evsel->id && evsel->id[0] == pt->returns_id) {
> > > + if (evsel->name)
> > > + zfree(&evsel->name);
> > > + evsel->name = strdup("return");
> > > + break;
> > > + }
> > > + }
> > > }
> > >
> > > pt->synth_needs_swap = evsel->needs_swap;
> > > --
> > > 2.5.5
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