linux-kernel - Re: [PATCH 1/4] perf, x86: Avoid checkpointed counters causing excessive TSX aborts v4

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Message-ID: <20130830204445.GF16724@tassilo.jf.intel.com>
Date:	Fri, 30 Aug 2013 13:44:45 -0700
From:	Andi Kleen <ak@...ux.intel.com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Andi Kleen <andi@...stfloor.org>, mingo@...nel.org,
	acme@...radead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/4] perf, x86: Avoid checkpointed counters causing
 excessive TSX aborts v4

On Fri, Aug 30, 2013 at 06:02:15PM +0200, Peter Zijlstra wrote:
> On Wed, Aug 21, 2013 at 04:47:23PM -0700, Andi Kleen wrote:
> > @@ -1224,6 +1240,15 @@ again:
> >  		x86_pmu.drain_pebs(regs);
> >  	}
> >  
> > +	/*
> > +	 * To avoid spurious interrupts with perf stat always reset checkpointed
> > +	 * counters.
> > +	 *
> > +	 * XXX move somewhere else.
> > +	 */
> > +	if (cpuc->events[2] && event_is_checkpointed(cpuc->events[2]))
> > +		status |= (1ULL << 2);
> > +
> >  	for_each_set_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
> >  		struct perf_event *event = cpuc->events[bit];
> >  
> 
> I'm sure I commented on that XXX thing.. 
> 
> Yep, right here:

Ok.

> 
>   http://marc.info/?l=linux-kernel&m=137638980210140
> 
> Sup?

I originally thought about precomputing the mask somewhere,
but it's not really that bad a place.

So can just drop the XXX comment. Ok?

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only
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