diff options
| author | Hugh Dickins <hughd@google.com> | 2021-06-30 18:52:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-30 20:47:30 -0700 |
| commit | ab02c252c8609c73ff2897c7e961b631e8bd409c (patch) | |
| tree | 4219b9d4b54a6a37cb4f52115fc4f1bd1988727a | |
| parent | 1fb08ac63beedf58e2ae9f229ea1f9474949a185 (diff) | |
| download | linux-ab02c252c8609c73ff2897c7e961b631e8bd409c.tar.bz2 | |
mm/thp: remap_page() is only needed on anonymous THP
THP splitting's unmap_page() only sets TTU_SPLIT_FREEZE when PageAnon, and
migration entries are only inserted when TTU_MIGRATION (unused here) or
TTU_SPLIT_FREEZE is set: so it's just a waste of time for remap_page() to
search for migration entries to remove when !PageAnon.
Link: https://lkml.kernel.org/r/f987bc44-f28e-688d-2424-b4722153ed8@google.com
Fixes: baa355fd3314 ("thp: file pages support for split_huge_page()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jue Wang <juew@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/huge_memory.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index dc0a0c82a5ac..503c8e1aecc6 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2307,6 +2307,7 @@ static void unmap_page(struct page *page) VM_BUG_ON_PAGE(!PageHead(page), page); + /* If TTU_SPLIT_FREEZE is ever extended to file, update remap_page() */ if (PageAnon(page)) ttu_flags |= TTU_SPLIT_FREEZE; @@ -2318,6 +2319,10 @@ static void unmap_page(struct page *page) 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 (!PageAnon(page)) + return; if (PageTransHuge(page)) { remove_migration_ptes(page, page, true); } else { |