diff options
| author | David Hildenbrand <david@redhat.com> | 2022-08-25 19:46:57 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-09-27 05:46:28 +0300 |
| commit | 474098edac262ae26bfab1c48445877075a31cbd (patch) | |
| tree | 4a3e87b877db5029d08b97e814d275d49d38f561 /include | |
| parent | f7091ed64ec8311b0c35865875f8c3e04e5ea532 (diff) | |
| download | linux-474098edac262ae26bfab1c48445877075a31cbd.tar.xz | |
mm/gup: replace FOLL_NUMA by gup_can_follow_protnone()
Patch series "mm: minor cleanups around NUMA hinting".
Working on some GUP cleanups (e.g., getting rid of some FOLL_ flags) and
preparing for other GUP changes (getting rid of FOLL_FORCE|FOLL_WRITE for
for taking a R/O longterm pin), this is something I can easily send out
independently.
Get rid of FOLL_NUMA, allow FOLL_FORCE access to PROT_NONE mapped pages in
GUP-fast, and fixup some documentation around NUMA hinting.
This patch (of 3):
No need for a special flag that is not even properly documented to be
internal-only.
Let's just factor this check out and get rid of this flag. The separate
function has the nice benefit that we can centralize comments.
Link: https://lkml.kernel.org/r/20220825164659.89824-2-david@redhat.com
Link: https://lkml.kernel.org/r/20220825164659.89824-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mm.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 37384a84f71a..eb25cae06c55 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2933,7 +2933,6 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, * and return without waiting upon it */ #define FOLL_NOFAULT 0x80 /* do not fault in pages */ #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */ -#define FOLL_NUMA 0x200 /* force NUMA hinting page fault */ #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */ #define FOLL_TRIED 0x800 /* a retry, previous pass started an IO */ #define FOLL_REMOTE 0x2000 /* we are working on non-current tsk/mm */ @@ -3054,6 +3053,21 @@ static inline bool gup_must_unshare(unsigned int flags, struct page *page) return !PageAnonExclusive(page); } +/* + * Indicates whether GUP can follow a PROT_NONE mapped page, or whether + * a (NUMA hinting) fault is required. + */ +static inline bool gup_can_follow_protnone(unsigned int flags) +{ + /* + * FOLL_FORCE has to be able to make progress even if the VMA is + * inaccessible. Further, FOLL_FORCE access usually does not represent + * application behaviour and we should avoid triggering NUMA hinting + * faults. + */ + return flags & FOLL_FORCE; +} + typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data); extern int apply_to_page_range(struct mm_struct *mm, unsigned long address, unsigned long size, pte_fn_t fn, void *data); |