Re: [PATCH v8 4/5] locking/qspinlock: Introduce starvation avoidance into CNA

Alex Kogan
2020-01-30T22:06:35Z

> On Jan 25, 2020, at 6:19 AM, Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Fri, Jan 24, 2020 at 01:19:05PM -0500, Alex Kogan wrote:
>
>> Is there a lightweight way to identify such a “prioritized” thread?
>
> No; people might for instance care about tail latencies between their
> identically spec'ed worker tasks.

I would argue that those users need to tune/reduce the intra-node handoff
threshold for their needs. Or disable CNA altogether.

In general, Peter, seems like you are not on board with the way Longman
suggested to handle prioritized threads. Am I right?

Thanks,
— Alex