From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Shi Subject: [PATCH v7 02/10] mm/memcg: fold lru_lock in lock_page_lru Date: Wed, 25 Dec 2019 17:04:18 +0800 Message-ID: <1577264666-246071-3-git-send-email-alex.shi@linux.alibaba.com> References: <1577264666-246071-1-git-send-email-alex.shi@linux.alibaba.com> Return-path: In-Reply-To: <1577264666-246071-1-git-send-email-alex.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, yang.shi@linux.alibaba.com, willy@infradead.org, shakeelb@google.com, hannes@cmpxchg.org Cc: Michal Hocko , Vladimir Davydov >From the commit_charge's explanations and mem_cgroup_commit_charge comments, as well as call path when lrucare is ture, The lru_lock is just to guard the task migration(which would be lead to move_account) So it isn't needed when !PageLRU, and better be fold into PageLRU to reduce lock contentions. Signed-off-by: Alex Shi Cc: Johannes Weiner Cc: Michal Hocko Cc: Matthew Wilcox Cc: Vladimir Davydov Cc: Andrew Morton Cc: cgroups@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/memcontrol.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c5b5f74cfd4d..0ad10caabc3d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2572,12 +2572,11 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) static void lock_page_lru(struct page *page, int *isolated) { - pg_data_t *pgdat = page_pgdat(page); - - spin_lock_irq(&pgdat->lru_lock); if (PageLRU(page)) { + pg_data_t *pgdat = page_pgdat(page); struct lruvec *lruvec; + spin_lock_irq(&pgdat->lru_lock); lruvec = mem_cgroup_page_lruvec(page, pgdat); ClearPageLRU(page); del_page_from_lru_list(page, lruvec, page_lru(page)); @@ -2588,17 +2587,17 @@ static void lock_page_lru(struct page *page, int *isolated) static void unlock_page_lru(struct page *page, int isolated) { - pg_data_t *pgdat = page_pgdat(page); if (isolated) { + pg_data_t *pgdat = page_pgdat(page); struct lruvec *lruvec; lruvec = mem_cgroup_page_lruvec(page, pgdat); VM_BUG_ON_PAGE(PageLRU(page), page); SetPageLRU(page); add_page_to_lru_list(page, lruvec, page_lru(page)); + spin_unlock_irq(&pgdat->lru_lock); } - spin_unlock_irq(&pgdat->lru_lock); } static void commit_charge(struct page *page, struct mem_cgroup *memcg, -- 1.8.3.1