Re: [PATCH v9 2/2] mm/memory hotplug/unplug: Optimize zone->contiguous update when changes pfn range

[Li, Tianyou]

Hi David,


Yuan has create another patch with test result. He will submit the patch 
soon. Thanks in advance for your kind review.


Regards,

Tianyou



On 3/11/2026 11:02 PM, Li, Tianyou wrote:

> On 3/9/2026 10:26 PM, David Hildenbrand (Arm) wrote:
> > On 3/9/26 01:42, Li, Tianyou wrote:
> > > Hi David, Mike & Other maintainers,
> > Hi!
> >
> > > Just a quick update: Yuan and I created a new patch based on David and
> > > Mike's code, updated the documentation as well, performed the
> > > performance test, double check all the references etc. We observed a
> > > slightly performance regression, not sure it was caused by the
> > > environment configuration or we triggered some unexpected behavior. We
> > > might need a bit more time to investigate. Will send out the patch soon
> > > once we have confirmed data for the performance regression. Thanks.
> > A performance regression would be rather unexpected, unless we somehow
> > don't ever set zone->contiguous=true any more :)
> >
> > In which test / code path did you observe a regression?
>
>
> Sorry for the late response, I missed the email by accident. The test 
> is simply hotplug and unplug the 256GB memory, the time became 3s 
> instead of 2s for some reason compared to previous patch. 
> Interestingly, for 512GB memory hotplug/unplug, the time remains as 
> 6s. What we planned to do are: 1. double/triple check with the same 
> and other servers; 2. collect the perf profile to see what is the diff 
> compared with previous patch, if the regression consistently persisted.
>
> I will work with Yuan on this and hopefully we can have more 
> information to be shared here soon. Thanks.
>
>
> Regards,
>
> Tianyou