Re: [PATCH v4 0/9] perf, x86: large PEBS interrupt threshold

[Andi Kleen]

Peter Zijlstra <peterz@xxxxxxxxxxxxx> writes:
>
> No feedback on the correctness aspects of the overflow crap?

I assume you mean collisions? See below.

> A quick look at patch 6 reads like you still don't understand the issue
> right. There are no 'collisions' as such in PEBS record generation, or
> are there? See the earlier open discussion.

There can be collisions, but they are in practice extremely rare.

The only way you can get a lot of collision is if you count
the same thing multiple times which is not a useful configuration.
A single monitoring tool only needs a single event once.
While multiple processes may be configuring multiple events
at the same time, they will not start them at the same
time which also prevents collisions.

-Andi

-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only
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