Re: [PATCH RFC] mm/madvise: introduce MADV_POPULATE to prefault/prealloc memory

From: David Hildenbrand
Date: Sat Feb 20 2021 - 04:03:22 EST


Sorry, for jumping in late ... hugetlb keyword just hit my mail filters :)


Sorry for not realizing to cc you before I sent out the man page update :)

Yes, it is true that hugetlb reservations are not numa aware. So, even if
pages are reserved at mmap time one could still SIGBUS if a fault is
restricted to a node with insufficient pages.

I looked into this some years ago, and there really is not a good way to
make hugetlb reservations numa aware. preallocation, or on demand
populating as proposed here is a way around the issue.


Thanks for confirming, this makes a lot of sense to me now.


--
Thanks,

David / dhildenb