On Thu, 2023-09-21 at 15:42 -0700, Mike Kravetz wrote: > On 09/19/23 22:16, 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. > > > > 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 | 36 ++++++++++++++++++++++++++++++++---- > > 2 files changed, 38 insertions(+), 4 deletions(-) > > This looks straight forward. > > However, I ran just this patch through libhugetlbfs test suite and it > hung on > misaligned_offset (2M: 32). > https://github.com/libhugetlbfs/libhugetlbfs/blob/master/tests/misaligned_offset.c Speaking of "looks straightforward", how do I compile the libhugetlbfs code? The __morecore variable, which is pointed at either the THP or hugetlbfs morecore function, does not seem to be defined anywhere in the sources. Do I need to run some magic script (didn't find it) to get a special header file set up before I can build libhugetlbfs? $ make CC32 obj32/morecore.o morecore.c: In function ‘__lh_hugetlbfs_setup_morecore’: morecore.c:368:17: error: ‘__morecore’ undeclared (first use in this function); did you mean ‘thp_morecore’? 368 | __morecore = &thp_morecore; | ^~~~~~~~~~ | thp_morecore morecore.c:368:17: note: each undeclared identifier is reported only once for each function it appears in make: *** [Makefile:292: obj32/morecore.o] Error 1 $ grep __morecore *.[ch] morecore.c: __morecore = &thp_morecore; morecore.c: __morecore = &hugetlbfs_morecore; -- All Rights Reversed.
