[PATCH 4.19 03/34] mm/rmap: use page_not_mapped in try_to_unmap()
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-07-09 13:21:34
Also in:
lkml
Subsystem:
memory management, memory management - rmap (reverse mapping), the rest · Maintainers:
Andrew Morton, David Hildenbrand, Lorenzo Stoakes, Linus Torvalds
From: Miaohe Lin <linmiaohe@huawei.com> [ Upstream commit b7e188ec98b1644ff70a6d3624ea16aadc39f5e0 ] page_mapcount_is_zero() calculates accurately how many mappings a hugepage has in order to check against 0 only. This is a waste of cpu time. We can do this via page_not_mapped() to save some possible atomic_read cycles. Remove the function page_mapcount_is_zero() as it's not used anymore and move page_not_mapped() above try_to_unmap() to avoid identifier undeclared compilation error. Link: https://lkml.kernel.org/r/20210130084904.35307-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- mm/rmap.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index 69ce68616cbf..70872d5b203c 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c@@ -1682,9 +1682,9 @@ static bool invalid_migration_vma(struct vm_area_struct *vma, void *arg) return is_vma_temporary_stack(vma); } -static int page_mapcount_is_zero(struct page *page) +static int page_not_mapped(struct page *page) { - return !total_mapcount(page); + return !page_mapped(page); } /**
@@ -1702,7 +1702,7 @@ bool try_to_unmap(struct page *page, enum ttu_flags flags) struct rmap_walk_control rwc = { .rmap_one = try_to_unmap_one, .arg = (void *)flags, - .done = page_mapcount_is_zero, + .done = page_not_mapped, .anon_lock = page_lock_anon_vma_read, };
@@ -1726,11 +1726,6 @@ bool try_to_unmap(struct page *page, enum ttu_flags flags) return !page_mapcount(page) ? true : false; } -static int page_not_mapped(struct page *page) -{ - return !page_mapped(page); -} - /** * try_to_munlock - try to munlock a page * @page: the page to be munlocked
--
2.30.2