Messages in this thread |  | | Subject | Re: [PATCH V4 09/10] power8, perf: Change BHRB branch filter configuration | From | Michael Ellerman <> | Date | Wed, 18 Dec 2013 11:08:05 +1100 |
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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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