Messages in this thread | | | Date | Fri, 11 Jul 2014 10:15:10 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH 2/4] perf/x86: add support for sampling PEBS machine state registers |
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On Wed, Jul 09, 2014 at 12:15:57AM +0200, Stephane Eranian wrote: > PEBS can capture machine state regs at retirement of the sampled > instructions. When precise sampling is enabled on an event, PEBS > is used, so substitute the interrupted state with the PEBS state. > Note that not all registers are captured by PEBS. Those missing > are replaced by the interrupt state counter-parts. > > Signed-off-by: Stephane Eranian <eranian@google.com> > --- > arch/x86/kernel/cpu/perf_event_intel_ds.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c > index 980970c..d612bcd 100644 > --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c > +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c > @@ -925,6 +925,25 @@ static void __intel_pmu_pebs_event(struct perf_event *event, > regs.bp = pebs->bp; > regs.sp = pebs->sp; > > + if (sample_type & PERF_SAMPLE_REGS_INTR) { > + regs.ax = pebs->ax; > + regs.bx = pebs->bx; > + regs.cx = pebs->cx; > + regs.si = pebs->si; > + regs.di = pebs->di; > + > + regs.r8 = pebs->r8; > + regs.r9 = pebs->r9; > + regs.r10 = pebs->r10; > + regs.r11 = pebs->r11; > + regs.r12 = pebs->r12; > + regs.r13 = pebs->r13; > + regs.r14 = pebs->r14; > + regs.r14 = pebs->r15; > + > + data.regs_intr.regs = ®s;
this assignement is not necessary, because you assign this regs pointer again in perf_prepare_sample -> perf_sample_regs_intr later
jirka
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