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.
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/rmap.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index c3f6e060d73f..b49e85605f8f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1736,9 +1736,9 @@ static bool invalid_migration_vma(struct vm_area_struct *vma, void *arg)
return vma_is_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);
}
/**
@@ -1756,7 +1756,7 @@ 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,
};
@@ -1780,11 +1780,6 @@ 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
--
2.19.1
