From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: 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@xxxxxxxxxx Link: https://lkml.kernel.org/r/20210330140228.45635-2-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/ksm.c | 2 -- 1 file changed, 2 deletions(-) --- a/mm/ksm.c~ksm-remove-redundant-vm_bug_on_page-on-stable_tree_search +++ a/mm/ksm.c @@ -1771,7 +1771,6 @@ chain_append: * 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 @@ chain_append: * 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); _
