From abbe9a8fef03fc3973634e99785a1b04a0649f7e Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Mon, 22 Feb 2021 10:59:22 +0800 Subject: [PATCH] mm: thp: don't need care deferred split queue in memcg charge move path mainline inclusion from mainline-v5.6-rc1 commit fac0516b5534897bf4c4a88daa06a8cfa5611b23 category: bugfix bugzilla: 47240 CVE: NA ------------------------------------------------- If compound is true, this means it is a PMD mapped THP. Which implies the page is not linked to any defer list. So the first code chunk will not be executed. Also with this reason, it would not be proper to add this page to a defer list. So the second code chunk is not correct. Based on this, we should remove the defer list related code. [yang.shi@linux.alibaba.com: better patch title] Link: http://lkml.kernel.org/r/20200117233836.3434-1-richardw.yang@linux.intel.com Fixes: 87eaceb3faa5 ("mm: thp: make deferred split shrinker memcg aware") Signed-off-by: Wei Yang Suggested-by: Kirill A. Shutemov Acked-by: Yang Shi Cc: David Rientjes Cc: Michal Hocko Cc: Kirill A. Shutemov Cc: Johannes Weiner Cc: Vladimir Davydov Cc: [5.4+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Liu Shixin Reviewed-by: Kefeng Wang Signed-off-by: Yang Yingliang Signed-off-by: Cheng Jian --- mm/memcontrol.c | 18 ------------------ 1 file changed, 18 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index eabe38a0d56f..dca37f310b7b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4948,14 +4948,6 @@ static int mem_cgroup_move_account(struct page *page, __mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages); } -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - if (compound && !list_empty(page_deferred_list(page))) { - spin_lock(&from->deferred_split_queue.split_queue_lock); - list_del_init(page_deferred_list(page)); - from->deferred_split_queue.split_queue_len--; - spin_unlock(&from->deferred_split_queue.split_queue_lock); - } -#endif /* * It is safe to change page->mem_cgroup here because the page * is referenced, charged, and isolated - we can't race with @@ -4965,16 +4957,6 @@ static int mem_cgroup_move_account(struct page *page, /* caller should have done css_get */ page->mem_cgroup = to; -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - if (compound && list_empty(page_deferred_list(page))) { - spin_lock(&to->deferred_split_queue.split_queue_lock); - list_add_tail(page_deferred_list(page), - &to->deferred_split_queue.split_queue); - to->deferred_split_queue.split_queue_len++; - spin_unlock(&to->deferred_split_queue.split_queue_lock); - } -#endif - spin_unlock_irqrestore(&from->move_lock, flags); ret = 0; -- GitLab