Hi Matthew Thanks for your prompt response. I had already jumped to the conclusion that the folio abstraction idea would effectively negate the need for additional huge pages. It seems that I was wrong. I can definitely try to connect you with our developers, however, I first wanted to assess whether there was real interest from the relevant kernel.org maintainers. I don't want our technical people spending time on work that will not be of overall benefit. In my opinion, it would be good to see this code as a standard Linux feature so that our developers can devote their attention to other work. Our focus is HPC so I had assumed that the feature would have limited interest in the broader Linux community. As previously stated, I am cannot find much evidence the current benefits from huge pages above 2 MB but I am certainly not qualified to discuss the low level details. Des -----Original Message----- From: Matthew Wilcox <willy@xxxxxxxxxxxxx> Sent: Friday, July 22, 2022 12:39 PM To: Albert, Des <des.albert@xxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>; songmuchun@xxxxxxxxxxxxx; linux-mm@xxxxxxxxx Subject: Re: Additional Huge Pages On Fri, Jul 22, 2022 at 07:20:51PM +0000, Albert, Des wrote: > This is the first time I have heard of the folio abstraction as the future for memory management. When you mention that future hugetbls work will be based on that concept, it seems unlikely that there would be interest in code that is not consistent with those developments. I also doubt that there would be a justification to 'update' the code to be consistent with future kernel developments. > > I am therefore forming the impression that this idea may not be of interest to the Linux kernel community, however, I do not the detailed technical depth of the development team. > > Do you have some more information about this folio abstraction plan ? Hi Des! I'm the lead on the folio abstraction plan, so hopefully I can be of some help. Folios, like your Cray Hugepages, broaden the supported page sizes. They were originally conceived for relatively small page sizes (eg 16kB-256kB) and have been implemented so far only for the XFS filesystem. Other filesystems are in progress. This is the first hint we've had that people are interested in folio sizes above 2MB. I think the folio work should make supporting this Cray requirement much easier. It's certainly good to know that this is interesting before we do too much work on converting the existing hugetlb code over to folios. Are you able to direct any developers to help us with this? We can definitely work together on this project; we've had a similar collaboration running for a few years now on the Transparent Huge Page side of things.
