From: Miaohe Lin linmiaohe@huawei.com
stable inclusion from stable-5.10.47 commit bfd90b56d7f6cb225d6c31d2620cecc1a75d6142 bugzilla: 172973 https://gitee.com/openeuler/kernel/issues/I4DAKB
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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 Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- mm/rmap.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c index 1928ca98d56d..13df44196177 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1722,9 +1722,9 @@ 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); }
/** @@ -1742,7 +1742,7 @@ 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, };
@@ -1766,11 +1766,6 @@ 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