From: Muchun Song <songmuchun@xxxxxxxxxxxxx> Subject: mm: memcontrol: simplify lruvec_holds_page_lru_lock We already have a helper lruvec_memcg() to get the memcg from lruvec, we do not need to do it ourselves in the lruvec_holds_page_lru_lock(). So use lruvec_memcg() instead. And if mem_cgroup_disabled() returns false, the page_memcg(page) (the LRU pages) cannot be NULL. So remove the odd logic of "memcg = page_memcg(page) ? : root_mem_cgroup". And use lruvec_pgdat to simplify the code. We can have a single definition for this function that works for !CONFIG_MEMCG, CONFIG_MEMCG + mem_cgroup_disabled() and CONFIG_MEMCG. Link: https://lkml.kernel.org/r/20210417043538.9793-5-songmuchun@xxxxxxxxxxxxx Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Acked-by: Roman Gushchin <guro@xxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Xiongchun Duan <duanxiongchun@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/memcontrol.h | 31 +++++++------------------------ 1 file changed, 7 insertions(+), 24 deletions(-) --- a/include/linux/memcontrol.h~mm-memcontrol-simplify-lruvec_holds_page_lru_lock +++ a/include/linux/memcontrol.h @@ -755,22 +755,6 @@ static inline struct lruvec *mem_cgroup_ return mem_cgroup_lruvec(memcg, pgdat); } -static inline bool lruvec_holds_page_lru_lock(struct page *page, - struct lruvec *lruvec) -{ - pg_data_t *pgdat = page_pgdat(page); - const struct mem_cgroup *memcg; - struct mem_cgroup_per_node *mz; - - if (mem_cgroup_disabled()) - return lruvec == &pgdat->__lruvec; - - mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec); - memcg = page_memcg(page) ? : root_mem_cgroup; - - return lruvec->pgdat == pgdat && mz->memcg == memcg; -} - struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p); struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm); @@ -1227,14 +1211,6 @@ static inline struct lruvec *mem_cgroup_ return &pgdat->__lruvec; } -static inline bool lruvec_holds_page_lru_lock(struct page *page, - struct lruvec *lruvec) -{ - pg_data_t *pgdat = page_pgdat(page); - - return lruvec == &pgdat->__lruvec; -} - static inline void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page) { } @@ -1516,6 +1492,13 @@ static inline void unlock_page_lruvec_ir spin_unlock_irqrestore(&lruvec->lru_lock, flags); } +static inline bool lruvec_holds_page_lru_lock(struct page *page, + struct lruvec *lruvec) +{ + return lruvec_pgdat(lruvec) == page_pgdat(page) && + lruvec_memcg(lruvec) == page_memcg(page); +} + /* Don't lock again iff page's lruvec locked */ static inline struct lruvec *relock_page_lruvec_irq(struct page *page, struct lruvec *locked_lruvec) _
