Re: [generalized cache events] Re: [PATCH 1/1] perf tools: Addmissing user space support for config1/config2

[Andi Kleen]

> One could argue that all you need is cycles and instructions. If there is an
> expensive load, you'll see that the load instruction takes many cycles and
> you can infer that it's a cache miss.

That is when you can actually recognize which of the last load instructions
caused the problem. Often skid on Out of order CPUs makes this very hard to 
identify which actual load caused the the long stall (or if they all stalled)

There's a way around it of course using advanced events, but not with
cycles.

> I don't see why exposing all vendor defined events is harmful

Simple: without vendor events you cannot answer a lot of questions.

-Andi

-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only
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