Support for ARM ECMDQs

[John Garry]

On 10/14/26 15:07, Sukadev Bhattiprolu wrote:
> Hi,
> 
> We are trying to understand the direction or ongoing efforts to support enhanced
> command queues (ECMDQs) in Linux.
> 
> Earlier version of patches [1] seem to have stalled due to lack of real-world
> workload data.
> 
> Also, any recommendations on policies to distribute available eCMDQs - one per
> CPU as in [1] or, round-robin when # of eCMDQs are less than # of CPUs or others?
> 

I'd expect a static spread over all CPUs to improve caching of the cmdq 
memory structures.

> Thanks,
> Sukadev
> 
> [1] https://lkml.indiana.edu/hypermail/linux/kernel/2404.3/07988.html

As you can see in that thread, the maintainers wanted to see results 
from real-world workloads (which never appeared).

And I think that the preemption disabling scheme in that series can be 
improved (dropped).