UFFD_FEATURE_THREAD_ID is supported in Linux 4.14. Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> --- man2/ioctl_userfaultfd.2 | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/man2/ioctl_userfaultfd.2 b/man2/ioctl_userfaultfd.2 index 47ae5f473..d4a8375b8 100644 --- a/man2/ioctl_userfaultfd.2 +++ b/man2/ioctl_userfaultfd.2 @@ -208,6 +208,11 @@ signal will be sent to the faulting process. Applications using this feature will not require the use of a userfaultfd monitor for processing memory accesses to the regions registered with userfaultfd. +.TP +.BR UFFD_FEATURE_THREAD_ID " (since Linux 4.14)" +If this feature bit is set, +.I uffd_msg.pagefault.feat.ptid +will be set to the faulted thread ID for each page fault message. .PP The returned .I ioctls -- 2.26.2