Messages in this thread |  | | Date | Wed, 07 Nov 2018 22:04:24 -0800 (PST) | | Subject | Re: [PATCH RFC] hist lookups | | From | David Miller <> |
| |
From: Arnaldo Carvalho de Melo <acme@kernel.org> Date: Wed, 7 Nov 2018 17:28:15 -0300
> So perhaps we should tell the kernel that is ok to lose SAMPLEs but not > the other events, and make userspace ask for PERF_RECORD_!SAMPLE in all > ring buffers? Duplication wouldn't be that much of a problem?
I think we should strive to keep the policy in userspace.
The kernel simply provides the events that happen, and the user's job is to take the events in sort of a "high priority interrupt" context and push the slow path processing to a separate thread of execution where drop policy can be implemented.
Jiri's work provides a framework for exactly that.
So what we can have is:
cpu1 cpu2 cpu3 cpu4 cpu5 cpu6 ... cpuN | | | | | | | ---------------------------------------- | | | single event ring buffer | | ultra-fast perf event dequeue queues in-order to event processing | event processing slow path prioritization and drop policy histogram insert etc.
|  |