Re: [PATCH] driver core: Use unbound workqueue for deferred probes

Yogesh Lal
2021-02-25T10:37:06Z

Hi Greg,

On 2/24/2021 6:13 PM, Greg KH wrote:
> On Wed, Feb 24, 2021 at 05:25:49PM +0530, Yogesh Lal wrote:
>> Queue deferred driver probes on unbounded workqueue, to allow
>> scheduler better manage scheduling of long running probes.
>
> Really? What does this change and help? What is the visable affect of
> this patch? What problem does it solve?
>

We observed boot up improvement (~400 msec) when the deferred probe work
is made unbound. This is due to scheduler moving the worker running
deferred probe work to big CPUs. without this change, we see the worker
is running on LITTLE CPU due to affinity.
​
Please let us now if there are any concerns/restrictions that deferred
probe work should run only on pinned kworkers. Since this work runs
deferred probe of several devices , the locality may not be that important

Thanks
Yogesh Lal

> thanks,
>
> greg k-h