On Fri, 2013-12-13 at 13:50 +0530, Anshuman Khandual wrote:
> On 12/09/2013 11:51 AM, Michael Ellerman wrote:
> >
> > As I said in my comments on version 3 which you ignored:
> >
> > I think it would be clearer if we actually checked for the
> > possibilities we
> > allow and let everything else fall through, eg:
> >
> > Â Â Â Â Â Â Â Â /* Ignore user/kernel/hv bits */
> > Â Â Â Â Â Â Â Â branch_sample_type &= ~PERF_SAMPLE_BRANCH_PLM_ALL;
> >
> > Â Â Â Â Â Â Â Â if (branch_sample_type == PERF_SAMPLE_BRANCH_ANY)
> > Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â return 0;
> >
> > Â Â Â Â Â Â Â Â if (branch_sample_type == PERF_SAMPLE_BRANCH_ANY_CALL)
> > Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â return POWER8_MMCRA_IFM1;
> > Â
> > Â Â Â Â Â Â Â Â if (branch_sample_type == PERF_SAMPLE_BRANCH_COND)
> > Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â return POWER8_MMCRA_IFM3;
> > Â Â Â Â Â Â Â Â
> > Â Â Â Â Â Â Â Â return -1;
> >
>
> Hey Michael,
>
> This patch only adds support for the PERF_SAMPLE_BRANCH_COND filter, if the
> over all code flow does not clearly suggest that all combinations of any of
> these HW filters are invalid, then we can go with one more patch to clean
> that up before or after this patch but not here in this patch. Finally the
> code section here will look something like this. Does it sound good ?
Better, but not quite.
> static u64 power8_bhrb_filter_map(u64 branch_sample_type)
> {
> u64 pmu_bhrb_filter = 0;
>
> /* BHRB and regular PMU events share the same privilege state
> * filter configuration. BHRB is always recorded along with a
> * regular PMU event. As the privilege state filter is handled
> * in the basic PMC configuration of the accompanying regular
> * PMU event, we ignore any separate BHRB specific request.
> */
>
> /* Ignore user, kernel, hv bits */
> branch_sample_type &= ~PERF_SAMPLE_BRANCH_PLM_ALL;
>
> if (branch_sample_type == PERF_SAMPLE_BRANCH_ANY)
> return pmu_bhrb_filter;
return 0;
>
>
> if (branch_sample_type == PERF_SAMPLE_BRANCH_ANY_CALL) {
> pmu_bhrb_filter |= POWER8_MMCRA_IFM1;
> return pmu_bhrb_filter;
return POWER8_MMCRA_IFM1;
> }
>
> if (branch_sample_type == PERF_SAMPLE_BRANCH_COND) {
> pmu_bhrb_filter |= POWER8_MMCRA_IFM3;
> return pmu_bhrb_filter;
return POWER8_MMCRA_IFM3;
> }
>
> /* Every thing else is unsupported */
> return -1;
> }
cheers
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