On 09/25/23 16:28, riel@xxxxxxxxxxx wrote: > From: Rik van Riel <riel@xxxxxxxxxxx> > > Extend the locking scheme used to protect shared hugetlb mappings > from truncate vs page fault races, in order to protect private > hugetlb mappings (with resv_map) against MADV_DONTNEED. The only time an anon hugetlb mapping would not have a resv_map would be in the case where MAP_NORESERVE was specified. In this case the user should be prepared for allocation failures. I am good with this approach not adding locking for the MAP_NORESERVE case. > Add a read-write semaphore to the resv_map data structure, and > use that from the hugetlb_vma_(un)lock_* functions, in preparation > for closing the race between MADV_DONTNEED and page faults. > > Signed-off-by: Rik van Riel <riel@xxxxxxxxxxx> > --- > include/linux/hugetlb.h | 6 ++++++ > mm/hugetlb.c | 41 +++++++++++++++++++++++++++++++++++++---- > 2 files changed, 43 insertions(+), 4 deletions(-) Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> -- Mike Kravetz
