Re: [RFC PATCH 5/5] perf: Implement perf_output_addr()

From: Peter Zijlstra
Date: Wed May 19 2010 - 03:58:32 EST

On Wed, 2010-05-19 at 09:21 +0200, Frederic Weisbecker wrote:

> I'm still not sure what you mean here by this multiplexing. Is
> this about per cpu multiplexing?

Suppose there's two events attached to the same tracepoint. Will you
write the tracepoint twice and risk different data in each, or will you
do it once and copy it into each buffer?

> There is another problem. We need something like
> perf_output_discard() in case the filter reject the event (which
> must be filled for this check to happen).

Yeah, I utterly hate that, I opted to let anything with a filter take
the slow path. Not only would I have to add a discard, but I'd have to
decrement the counter as well, which is a big no-no.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at