Re: [tip:perf/x86] perf, x86: Implement initial P4 PMU driver

[Lin Ming <ming.m.lin@intel.com>]

On Wed, 2010-03-17 at 00:23 +0800, Cyrill Gorcunov wrote:
> On Tue, Mar 16, 2010 at 05:07:33PM +0100, Robert Richter wrote:
> [...]
> > --
> > 
> > From: Robert Richter <robert.richter@amd.com>
> > Date: Tue, 16 Mar 2010 16:38:19 +0100
> > Subject: [PATCH] perf, x86: reporting error code that returns from x86_pmu.hw_config()
> > 
> > If x86_pmu.hw_config() fails a fixed error code (-EOPNOTSUPP) is
> > return even if a different error was reported. This patch fixes this.
> > 
> > Signed-off-by: Robert Richter <robert.richter@amd.com>
> > ---
> >  arch/x86/kernel/cpu/perf_event.c |    5 +++--
> >  1 files changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
> > index 4e2480f..8982d92 100644
> > --- a/arch/x86/kernel/cpu/perf_event.c
> > +++ b/arch/x86/kernel/cpu/perf_event.c
> > @@ -467,8 +467,9 @@ static int __hw_perf_event_init(struct perf_event *event)
> >  	hwc->last_tag = ~0ULL;
> >  
> >  	/* Processor specifics */
> > -	if (x86_pmu.hw_config(attr, hwc))
> > -		return -EOPNOTSUPP;
> > +	err = x86_pmu.hw_config(attr, hwc);
> > +	if (err)
> > +		return err;
> >  
> >  	if (!hwc->sample_period) {
> >  		hwc->sample_period = x86_pmu.max_period;
> > -- 
> > 1.7.0
> >
> 
> Though at moment all hw_config callees return 0, it's better
> to be ready if one day we may start returning some particular
> errors. Looks good to me. Objections?

Looks good.

Lin Ming

> 
> 	-- Cyrill