On 09.01.23 20:53, Mike Kravetz wrote:
On 01/05/23 11:47, David Hildenbrand wrote:
On 05.01.23 11:17, James Houghton wrote:
This series introduces the concept of HugeTLB high-granularity mapping
(HGM). This series teaches HugeTLB how to map HugeTLB pages at
high-granularity, similar to how THPs can be PTE-mapped.
Support for HGM in this series is for MAP_SHARED VMAs on x86 only. Other
architectures and (some) support for MAP_PRIVATE will come later.
Why even care about the complexity of COW-sharable anon pages? TBH, I'd just
limit this to MAP_SHARED and call it a day. Sure, we can come up with use
cases for everything (snapshotting VMs using fork while also support
optimized postcopy), but I think this would need some real justification for
the added complexity and possible (likely!) issues.
I believe the primary use case driving this beyond MAP_SHARED would be
poisoning due to memory errors. Extending HGM seems to be the most
elegant way to start providing better support for this.
Good point. Although I wonder if in practice, most applicable users
either already are, or should switch to, using MAP_SHARED hugetlb.
--
Thanks,
David / dhildenb
