Messages in this thread |  | | | Subject | Re: [PATCH 5/9] perf: Adding sysfs group format attribute for pmu device | | From | Peter Zijlstra <> | | Date | Wed, 01 Feb 2012 15:18:52 +0100 |
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On Wed, 2012-02-01 at 14:13 +0100, Jiri Olsa wrote: > > Are you are suggesting that a single event could use multiple groups > > because they may share some common fields, such as the event code? If > > so, I think that might be confusing. I think it would be better to > > have every group fully lay out the bits in the config{,1,2} fields so > > that you only need to specify one group per event, even if that leads to > > some redundancy (e.g. group1..n all have an eventcode field.) > > ok, it'd be the 'cpu::group1/config=1,config1=2,config2=3/u' then.. > > but let's see what Peter thinks about this, since he first suggested > to 'fix' this by having separate pmu drivers.. not format groups :)
I'm not convinced we need the whole grouping thing. Even x86 might have overlapping definitions, even for a single PMU (config1 contents will radically differ depending on the actual events used for instance).
All we should do is warn the user when overlapping masks are used in a single event definition and other than that just do as they tell us.
PMUs can always do an informal namespace thing if really needed, eg. by using a consistent prefix.
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