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authorMiaohe Lin <linmiaohe@huawei.com>2021-02-25 17:18:03 -0800
committerSasha Levin <sashal@kernel.org>2021-06-30 08:47:52 -0400
commit68ce37ebe0f28580be77f8488e4042e6d7700cb2 (patch)
treeb0a64ef29de1e42573d5eb434e8863c517f900b0
parent432b61863ac726c41188899fbda52561ade8f301 (diff)
mm/rmap: use page_not_mapped in try_to_unmap()
[ 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--mm/rmap.c11
1 files changed, 3 insertions, 8 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index ccc8a780e348..cbde11c06a76 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1690,9 +1690,9 @@ 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);
}
/**
@@ -1710,7 +1710,7 @@ 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,
};
@@ -1734,11 +1734,6 @@ 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