On Fri, Dec 18, 2020 at 4:51 AM Michal Hocko mhocko@suse.com wrote:
On Thu 17-12-20 13:52:40, Pavel Tatashin wrote:
In __get_user_pages_locked() i counts number of pages which should be long.
Do we know of any caller who would like to pin so many pages it wouldn't fit into an int? I suspect this is more to sync types of nr_pages and the iterator right. It would be better to be explicit about this in the changelog.
It is to sync types. I will add it to the changelog.
But, in general 32-bit increasingly becomes too small for handling page count proportional values. It is 8T for npages. For pinning may be a bit too large today, but I can image RDMA this size in the future.
Signed-off-by: Pavel Tatashin pasha.tatashin@soleen.com
Acked-by: Michal Hocko mhocko@suse.com
mm/gup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/gup.c b/mm/gup.c index 591d8e2dfc70..1ebb7cc2fbe4 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1481,7 +1481,7 @@ static long __get_user_pages_locked(struct mm_struct *mm, unsigned long start, { struct vm_area_struct *vma; unsigned long vm_flags;
int i;
long i; /* calculate required read or write permissions. * If FOLL_FORCE is set, we only require the "MAY" flags.-- 2.25.1
-- Michal Hocko SUSE Labs