mm/rmap: fix comments left over from recent changes

Parallel developments in mm/rmap.c have left behind some out-of-date
comments: try_to_migrate_one() also accepts TTU_SYNC (already commented
in try_to_migrate() itself), and try_to_migrate() returns nothing at
all.

TTU_SPLIT_FREEZE has just been deleted, so reword the comment about it
in mm/huge_memory.c; and TTU_IGNORE_ACCESS was removed in 5.11, so
delete the "recently referenced" comment from try_to_unmap_one() (once
upon a time the comment was near the removed codeblock, but they drifted
apart).

Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Link: https://lore.kernel.org/lkml/563ce5b2-7a44-5b4d-1dfd-59a0e65932a9@google.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Hugh Dickins 2021-07-07 13:06:17 -07:00 committed by Linus Torvalds
parent 98f7fdced2
commit 64b586d192
2 changed files with 2 additions and 7 deletions

View File

@ -2331,7 +2331,7 @@ static void remap_page(struct page *page, unsigned int nr)
{
int i;
/* If TTU_SPLIT_FREEZE is ever extended to file, remove this check */
/* If unmap_page() uses try_to_migrate() on file, remove this check */
if (!PageAnon(page))
return;
if (PageTransHuge(page)) {

View File

@ -1439,8 +1439,6 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
while (page_vma_mapped_walk(&pvmw)) {
/*
* If the page is mlock()d, we cannot swap it out.
* If it's recently referenced (perhaps page_referenced
* skipped over this mm) then we should reactivate it.
*/
if (!(flags & TTU_IGNORE_MLOCK)) {
if (vma->vm_flags & VM_LOCKED) {
@ -1687,8 +1685,7 @@ void try_to_unmap(struct page *page, enum ttu_flags flags)
* @arg: enum ttu_flags will be passed to this argument.
*
* If TTU_SPLIT_HUGE_PMD is specified any PMD mappings will be split into PTEs
* containing migration entries. This and TTU_RMAP_LOCKED are the only supported
* flags.
* containing migration entries.
*/
static bool try_to_migrate_one(struct page *page, struct vm_area_struct *vma,
unsigned long address, void *arg)
@ -1928,8 +1925,6 @@ static bool try_to_migrate_one(struct page *page, struct vm_area_struct *vma,
*
* Tries to remove all the page table entries which are mapping this page and
* replace them with special swap entries. Caller must hold the page lock.
*
* If is successful, return true. Otherwise, false.
*/
void try_to_migrate(struct page *page, enum ttu_flags flags)
{