On 09/24/22 11:06, Peter Xu wrote: > > Sorry I forgot to reply on this one. > > I didn't try linux-next, but I can easily reproduce this with mm-unstable > already, and I verified that Hugh's patch fixes the problem for shmem. > > When I was testing I found hugetlb selftest is broken too but with some > other errors: > > $ sudo ./userfaultfd hugetlb 100 10 > ... > bounces: 6, mode: racing ver read, ERROR: unexpected write fault (errno=0, line=779) > > The failing check was making sure all MISSING events are not triggered by > writes, but frankly I don't really know why it's required, and that check > existed since the 1st commit when test was introduced. > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c47174fc362a089b1125174258e53ef4a69ce6b8 > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/testing/selftests/vm/userfaultfd.c?id=c47174fc362a089b1125174258e53ef4a69ce6b8#n291 > > And obviously some recent hugetlb-related change caused that to happen. > > Dropping that check can definitely work, but I'll have a closer look soon > too to make sure I didn't miss something. Mike, please also let me know if > you are aware of this problem. > Peter, I am not aware of this problem. I really should make running ALL hugetlb tests part of my regular routine. If you do not beat me to it, I will take a look in the next few days. -- Mike Kravetz
