On Thu, 2 Nov 2017, Thomas Gleixner wrote:
> On Thu, 2 Nov 2017, Liang, Kan wrote:
> > > On Thu, 2 Nov 2017, Thomas Gleixner wrote:
> > > > On Thu, 2 Nov 2017, Liang, Kan wrote:
> > > > > 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;
>
> Fugly that is, but as its cleaned up later....
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?
I think your patch order is wrong and breaks bisectability all over the
place as you fixup the UNCORE_PMC_IDX_FIXED + 1 hackery in 5/5.
Thanks,
tglx
