On Tue, Mar 23, 2021 at 10:27:34AM +0200, Mike Rapoport wrote: > On Mon, Mar 22, 2021 at 06:08:45PM -0400, Peter Xu wrote: > > UFFD_FEATURE_THREAD_ID is supported since Linux 4.14. > > > > Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> > > --- > > man2/userfaultfd.2 | 13 +++++++++++++ > > 1 file changed, 13 insertions(+) > > > > diff --git a/man2/userfaultfd.2 b/man2/userfaultfd.2 > > index e7dc9f813..555e37409 100644 > > --- a/man2/userfaultfd.2 > > +++ b/man2/userfaultfd.2 > > @@ -77,6 +77,13 @@ When the last file descriptor referring to a userfaultfd object is closed, > > all memory ranges that were registered with the object are unregistered > > and unread events are flushed. > > .\" > > +.PP > > +Since Linux 4.14, userfaultfd page fault message can selectively embed faulting > > +thread ID information into the fault message. > > +One needs to enable this feature explicitly using the > > +.BR UFFD_FEATURE_THREAD_ID > > +feature bit when initializing the userfaultfd context. > > +By default, thread ID reporting is diabled. > > ^ disabled :) Right! :) I'll wait for another round of Alex's review before reposting. Thanks, -- Peter Xu