lkml.org 
[lkml]   [2017]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRE: [PATCH V3 1/5] perf/x86/intel/uncore: customized pmu event read for client IMC uncore
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

\
 
 \ /
  Last update: 2017-11-02 15:17    [W:0.045 / U:21.412 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site