From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: ksm: use GET_KSM_PAGE_NOLOCK to get ksm page in remove_rmap_item_from_tree() It's unnecessary to lock the page when get ksm page if we're going to remove the rmap item as page migration is irrelevant in this case. Use GET_KSM_PAGE_NOLOCK instead to save some page lock cycles. Link: https://lkml.kernel.org/r/20210330140228.45635-3-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/ksm.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/mm/ksm.c~ksm-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree +++ a/mm/ksm.c @@ -778,12 +778,11 @@ static void remove_rmap_item_from_tree(s struct page *page; stable_node = rmap_item->head; - page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK); + page = get_ksm_page(stable_node, GET_KSM_PAGE_NOLOCK); if (!page) goto out; hlist_del(&rmap_item->hlist); - unlock_page(page); put_page(page); if (!hlist_empty(&stable_node->hlist)) _
