Re: [PATCH] perf/core: Emit PERF_RECORD_LOST for pinned events

From: Peter Zijlstra
Date: Mon Jan 18 2021 - 16:20:36 EST

On Mon, Jan 18, 2021 at 12:43:23PM +0900, Namhyung Kim wrote:
> As of now we silently ignore pinned events when it's failed to be
> scheduled and make it error state not try to schedule it again.
> That means we won't get any samples for the event.
> But there's no way for users to notice and respond to it. Let's
> emit a lost event with a new misc bit to indicate this situation.

Users should get a read(2) error IIRC, does that not work?