On 1/17/23 07:58, Jason Gunthorpe wrote:
> Now that NULL locked doesn't have a special meaning we can just make it
> non-NULL in all cases and remove the special tests.
>
> get_user_pages() and pin_user_pages() can safely pass in a locked = 1
>
> get_user_pages_remote) and pin_user_pages_remote() can swap in a local
> variable for locked if NULL is passed.
>
> Remove all the NULL checks.
>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> ---
> mm/gup.c | 30 ++++++++++++++++++++----------
> 1 file changed, 20 insertions(+), 10 deletions(-)
>
...
Looks correct, just a few remaining comments that could be
removed or fixed up:
> @@ -1121,7 +1121,7 @@ static long __get_user_pages(struct mm_struct *mm,
> i = follow_hugetlb_page(mm, vma, pages, vmas,
> &start, &nr_pages, i,
> gup_flags, locked);
> - if (locked && *locked == 0) {
> + if (!*locked) {
Just above this function, there is a comment that can
be adjusted to remove the reference to possibly NULL locked
arg. This one:
* If @locked != NULL, *@locked will be set to 0 when mmap_lock is
* released by an up_read(). That can happen if @gup_flags does not
* have FOLL_NOWAIT.
There's another one above populate_vma_page_range():
* If @locked is NULL, it may be held for read or write and will
* be unperturbed.
*
* If @locked is non-NULL, it must held for read only and may be
* released. If it's released, *@locked will be set to 0.
...and another set, above faultin_vma_page_range():
* If @locked is NULL, it may be held for read or write and will be unperturbed.
*
* If @locked is non-NULL, it must held for read only and may be released. If
* it's released, *@locked will be set to 0.
thanks,
--
John Hubbard
NVIDIA
