Re: [PATCH RFC] hist lookups

David Miller
2018-11-09T01:07:24Z

From: Jiri Olsa <jolsa@redhat.com>
Date: Thu, 8 Nov 2018 08:13:03 +0100

> we could separated fork/mmaps to separate dummy event map, or just
> parse them out in the read thread and create special queue for them
> and drop just samples in case we are behind

What you say at the end here is basically what I am proposing.

Perf dequeues events from mmap ring as fast as possible.

Perf has two internal queues, high priority and low priority.

High priority events are never dropped.

Low priority events are dropped on overload, oldest first.