From a08e1e11c90f3e6020963b3ad097680768bc8567 Mon Sep 17 00:00:00 2001
From: Miaohe Lin <linmiaohe@huawei.com>
Date: Tue, 4 May 2021 18:37:37 -0700
Subject: [PATCH] ksm: remove redundant VM_BUG_ON_PAGE() on
stable_tree_search()
Patch series "Cleanup and fixup for ksm".
This series contains cleanups to remove unnecessary VM_BUG_ON_PAGE and
dedicated macro KSM_FLAG_MASK. Also this fixes potential missing
rmap_item for stable_node which would result in failed rmap_walk_ksm().
More details can be found in the respective changelogs.
This patch (of 4):
The same VM_BUG_ON_PAGE() check is already done in the callee. Remove
these extra caller one to simplify code slightly.
Link: https://lkml.kernel.org/r/20210330140228.45635-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210330140228.45635-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/ksm.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/mm/ksm.c b/mm/ksm.c
index 9694ee2c71de5..7b6bc10365963 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1771,7 +1771,6 @@ static struct page *stable_tree_search(struct page *page)
* stable_node_dup is the dup to replace.
*/
if (stable_node_dup == stable_node) {
- VM_BUG_ON(is_stable_node_chain(stable_node_dup));
VM_BUG_ON(is_stable_node_dup(stable_node_dup));
/* chain is missing so create it */
stable_node = alloc_stable_node_chain(stable_node_dup,
@@ -1785,7 +1784,6 @@ static struct page *stable_tree_search(struct page *page)
* of the current nid for this page
* content.
*/
- VM_BUG_ON(!is_stable_node_chain(stable_node));
VM_BUG_ON(!is_stable_node_dup(stable_node_dup));
VM_BUG_ON(page_node->head != &migrate_nodes);
list_del(&page_node->list);
--
GitLab