Commit 3e96b6a2 authored by Miaohe Lin's avatar Miaohe Lin Committed by Linus Torvalds
Browse files

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@huawei.com


Signed-off-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a08e1e11

mm/ksm.c

+1 −2
Original line number Diff line number Diff line
@@ -778,12 +778,11 @@ static void remove_rmap_item_from_tree(struct rmap_item *rmap_item) 
		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))