linux-kernel - Re: [PATCH V2 2/3] x86, perf: Add a separate Arch Perfmon v4 PMI handler

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Date:   Thu, 27 Sep 2018 16:39:04 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     "Liang, Kan" <kan.liang@...ux.intel.com>
Cc:     tglx@...utronix.de, mingo@...hat.com, acme@...nel.org,
        linux-kernel@...r.kernel.org, eranian@...gle.com,
        ak@...ux.intel.com, alexander.shishkin@...ux.intel.com
Subject: Re: [PATCH V2 2/3] x86, perf: Add a separate Arch Perfmon v4 PMI
 handler

On Thu, Sep 27, 2018 at 09:53:28AM -0400, Liang, Kan wrote:
> 
> 
> On 9/27/2018 8:51 AM, Peter Zijlstra wrote:
> > On Wed, Aug 08, 2018 at 12:12:07AM -0700, kan.liang@...ux.intel.com wrote:
> > > @@ -4325,6 +4428,8 @@ __init int intel_pmu_init(void)
> > >   		x86_pmu.extra_regs = intel_skl_extra_regs;
> > >   		x86_pmu.pebs_aliases = intel_pebs_aliases_skl;
> > >   		x86_pmu.pebs_prec_dist = true;
> > > +		x86_pmu.counter_freezing = disable_counter_freezing ?
> > > +					   false : true;
> > >   		/* all extra regs are per-cpu when HT is on */
> > >   		x86_pmu.flags |= PMU_FL_HAS_RSP_1;
> > >   		x86_pmu.flags |= PMU_FL_NO_HT_SHARING;
> > 
> > 
> > How about so instead? It is very much tied to the perfmon version, not
> > the FMS.
> > 
> 
> Yes, it matches the name of the handler.
> But the change as below is not sufficient. We have to temporarily disable
> counter_freezing in this patch for small core.
> The 3/3 patch will also be impact.
> 
> I will send V3 patch for these changes.

Hold on, I just munched the third patch on top as well.

Let me push out the lot so you can have a peek..

  https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/log/?h=perf/core