Re: [PATCH v10 4/5] locking/qspinlock: Introduce starvation avoidance into CNA

[Waiman Long]

This is a multi-part message in MIME format.
On 4/3/20 4:59 PM, Alex Kogan wrote:
> Keep track of the number of intra-node lock handoffs, and force
> inter-node handoff once this number reaches a preset threshold.
> The default value for the threshold can be overridden with
> the new kernel boot command-line option "numa_spinlock_threshold".
>
> Signed-off-by: Alex Kogan <alex.kogan@xxxxxxxxxx>
> Reviewed-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
> Reviewed-by: Waiman Long <longman@xxxxxxxxxx>
> ---

A major issue with setting a limit on the maximum intra-node lock 
transfer is that the worst case latency where a lock can be transferred 
to another node is indeterminant. How about changing it to a time-based 
limit?

Cheers,
Longman