Messages in this thread | | | From | "Liang, Kan" <> | Subject | RE: [PATCH V3 1/5] perf/x86/intel/uncore: customized pmu event read for client IMC uncore | Date | Thu, 2 Nov 2017 14:06:10 +0000 |
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> On Thu, 2 Nov 2017, Thomas Gleixner wrote: > > On Thu, 2 Nov 2017, Liang, Kan wrote: > > > > On Tue, 24 Oct 2017, kan.liang@intel.com wrote: > > > > > - if (event->hw.idx >= UNCORE_PMC_IDX_FIXED) > > > > > + if (event->hw.idx == UNCORE_PMC_IDX_FIXED) > > > > > shift = 64 - uncore_fixed_ctr_bits(box); > > > > > else > > > > > shift = 64 - uncore_perf_ctr_bits(box); diff --git > > > > > a/arch/x86/events/intel/uncore_snb.c > > > > > b/arch/x86/events/intel/uncore_snb.c > > > > > index db1127c..9d5cd3f 100644 > > > > > --- a/arch/x86/events/intel/uncore_snb.c > > > > > +++ b/arch/x86/events/intel/uncore_snb.c > > > > > @@ -498,6 +498,30 @@ static void snb_uncore_imc_event_del(struct > > > > perf_event *event, int flags) > > > > > snb_uncore_imc_event_stop(event, PERF_EF_UPDATE); } > > > > > > > > > > +static void snb_uncore_imc_event_read(struct perf_event *event) { > > > > > + struct intel_uncore_box *box = uncore_event_to_box(event); > > > > > + u64 prev_count, new_count, delta; > > > > > + int shift; > > > > > + > > > > > + if (event->hw.idx >= UNCORE_PMC_IDX_FIXED) > > > > > > > > And this needs to be >= because? > > > > > > Patch 5/5 will clean up the client IMC uncore. > > > Before that, we still need it to make client IMC uncore work. > > > > > > This patch isolates the >= case for client IMC uncore. > > > > Fair enough. A comment to that effect (even when removed later) would > > have avoided that question. > > Thinking more about it. The current code only supports the fixed one, right? > So why would it deal with anything > FIXED? >
There are two free running counters in IMC. To support the second one, the previous code implicitly do UNCORE_PMC_IDX_FIXED + 1. So it has to deal with > FIXED case.
case SNB_UNCORE_PCI_IMC_DATA_READS: base = SNB_UNCORE_PCI_IMC_DATA_READS_BASE; idx = UNCORE_PMC_IDX_FIXED; break; case SNB_UNCORE_PCI_IMC_DATA_WRITES: base = SNB_UNCORE_PCI_IMC_DATA_WRITES_BASE; idx = UNCORE_PMC_IDX_FIXED + 1; break; default: return -EINVAL;
Thanks, Kan
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