Messages in this thread | | | Date | Thu, 7 May 2020 14:46:52 -0700 | From | Andi Kleen <> | Subject | Re: [RFC PATCH 0/7] Share events between metrics |
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> > - without this change events within a metric may get scheduled > > together, after they may appear as part of a larger group and be > > multiplexed at different times, lowering accuracy - however, less > > multiplexing may compensate for this. > > I agree the heuristic in this patch set is naive and would welcome to > improve it from your toplev experience. I think this change is > progress on TopDownL1 - would you agree?
TopdownL1 in non SMT mode should always fit. Inside a group deduping always makes sense.
The problem is SMT mode where it doesn't fit. toplev tries to group each node and each level together.
> > I'm wondering if what is needed are flags to control behavior. For > example, avoiding the use of groups altogether. For TopDownL1 I see.
Yes the current situation isn't great.
For Topdown your patch clearly is an improvement, I'm not sure it's for everything though.
Probably the advanced heuristics are only useful for a few formulas, most are very simple. So maybe it's ok. I guess would need some testing over the existing formulas.
-Andi
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