mm: document mmu_notifier_invalidate_range_start_nonblock()

Document what mmu_notifier_invalidate_range_start_nonblock() is for.  Also
add a __must_check annotation to signal that callers must bail out if a
notifier vetoes the operation.

Link: https://lkml.kernel.org/r/20230918201832.265108-1-jannh@google.com
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Jann Horn 2023-09-18 22:18:32 +02:00 committed by Andrew Morton
parent 840ea53a8d
commit 7ced098fcf

View File

@ -459,7 +459,14 @@ mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
}
static inline int
/*
* This version of mmu_notifier_invalidate_range_start() avoids blocking, but it
* can return an error if a notifier can't proceed without blocking, in which
* case you're not allowed to modify PTEs in the specified range.
*
* This is mainly intended for OOM handling.
*/
static inline int __must_check
mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
{
int ret = 0;