Re: Additional Huge Pages

[Mike Kravetz <mike.kravetz@oracle.com>]

On 07/22/22 17:20, Albert, Des wrote:
> Hi
> 
> I am the Product Manager for the HPE Cray Operating System ( formerly Cray Linux Environment )
> 
> One of the features of this product is a component known as additional huge pages. This is kernel code that enables the selection of 'non-standard' huge page sizes.
> For example, the current implementation allows for selection of huge page sizes of 2, 4, 8, 16, 32, 64, 128, 256 and 512 MB as well as 1 and 2 GB.
> 

Interesting.
Are these non-standard huge pages sizes targeted at application usage,
or internal kernel APIs.  If applications, what API is used?  Is it
similar/the same as hugetlb?

Within the kernel, support for 'arbitrary page sizes' is provided by the
folio abstraction.  hugetlb code will be moving to that in the future.
Any new code such as this whould be based on folios.

> We are currently evaluating the concept of providing this code to kernel.org. I realize that this would require dedication of technical resources to work with maintainers.
> 
> I would like to know if there is interest in this suggestion. I realize that Transparent Huge Pages may be regarded as a more general approach to this requirement.
> 

I guess interest would depend on the use cases and potential advantages
of this feature.  You should be able to speak to this based on your
current usage.
-- 
Mike Kravetz