On Mon 08-03-21 16:18:52, Mike Kravetz wrote: [...] > Converting larger to smaller hugetlb pages can be accomplished today by > first freeing the larger page to the buddy allocator and then allocating > the smaller pages. However, there are two issues with this approach: > 1) This process can take quite some time, especially if allocation of > the smaller pages is not immediate and requires migration/compaction. > 2) There is no guarantee that the total size of smaller pages allocated > will match the size of the larger page which was freed. This is > because the area freed by the larger page could quickly be > fragmented. I will likely not surprise to show some level of reservation. While your concerns about reconfiguration by existing interfaces are quite real is this really a problem in practice? How often do you need such a reconfiguration? Is this all really worth the additional code to something as tricky as hugetlb code base? > include/linux/hugetlb.h | 8 ++ > mm/hugetlb.c | 199 +++++++++++++++++++++++++++++++++++++++- > 2 files changed, 204 insertions(+), 3 deletions(-) > > -- > 2.29.2 > -- Michal Hocko SUSE Labs
