Re: [PATCH] perf/ftrace : Fix repetitious traces when specify a target task

[Peter Zijlstra]

On Tue, Oct 10, 2017 at 08:18:13PM +0800, chengjian (D) wrote:

> and what cases should the events be delivered multiple times?


Task-A		Task-B		Task-C		Task-D

fd = sys_perf_event_open(B)			fd = sys_perf_event_open(C)

		wake_up_process(C)

Here A traces B, and D traces C. When B wakes C, we want both A and D to
get the event.