On Sun, Jan 21, 2018 at 02:59:29PM -0800, Davidlohr Bueso wrote:
> Since we currently hold mmap_sem across both gup calls (and
> nothing more), we can substitute it with two _fast()
> alternatives and possibly avoid grabbing the lock.
>
> This was found while adding mmap_sem wrappers, and was also
> previously reported by Al: https://lkml.org/lkml/2017/11/17/777
See commit 9a949e8ff92246c0753b2805c2a001cb991fffe5
Author: Al Viro <v...@zeniv.linux.org.uk>
Date: Sat Nov 18 14:37:46 2017 -0500
cris: switch to get_user_pages_fast()
no point holding ->mmap_sem over both calls.
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
in -next...
