RE: [PATCH V3 1/5] perf/x86/intel/uncore: customized pmu event read for client IMC uncore

From: Thomas Gleixner
Date: Thu Nov 02 2017 - 10:57:01 EST


On Thu, 2 Nov 2017, Liang, Kan wrote:
> > On Thu, 2 Nov 2017, Thomas Gleixner wrote:
> > But then you have this in uncore_perf_event_update():
> >
> > - if (event->hw.idx >= UNCORE_PMC_IDX_FIXED)
> > + if (event->hw.idx == UNCORE_PMC_IDX_FIXED)
> >
> > So how is that supposed to work?
>
> This is for generic code.
>
> In previous code, the event_read function for IMC use generic code.
> So we have to deal with >= in generic code.
>
> Now, customized event_read function 'snb_uncore_imc_event_read'
> is introduced for IMC. So IMC does not touch the generic code.
> The generic code is corrected here.

The customized read function does not help at all.

uncore_perf_event_update() is used from snb_uncore_imc_event_stop(). So
it's broken with this patch.

This is a complete and utter mess to review.

Thanks,

tglx