Messages in this thread Patch in this message | | | 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 |
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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 <alex.shi@linux.alibaba.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> 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
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