Re: [PATCH] locking/mutex: Avoid spinner vs waiter starvation

From: huang ying
Date: Thu Feb 04 2016 - 03:55:54 EST


Hi, Low,

On Thu, Feb 4, 2016 at 9:35 AM, Jason Low <jason.low2@xxxxxx> wrote:
> I've done some testing with this patch with some of the AIM7 workloads
> and found that this reduced throughput by about 10%. The reduction in
> throughput is expected since spinning as a waiter is less efficient.
>
> Another observation I made is that the top waiter spinners would often
> times require needing to reschedule before being able to acquire the
> lock from spinning when there was high contention. A waiter can go into
> the cycle of spin -> reschedule -> spin -> reschedule. So although the
> chance of starvation is reduced, this patch doesn't fully address the
> issue of waiter starvation.

Could you share your workload? I want to reproduce it in 0day/LKP+ environment.

Best Regards,
Huang, Ying