From 36c7b4db7c942ae9e1b111f0c6b468c8b2e33842 Mon Sep 17 00:00:00 2001 From: "T.J. Alumbaugh" Date: Wed, 18 Jan 2023 00:18:24 +0000 Subject: mm: multi-gen LRU: section for memcg LRU Move memcg LRU code into a dedicated section. Improve the design doc to outline its architecture. Link: https://lkml.kernel.org/r/20230118001827.1040870-5-talumbau@google.com Signed-off-by: T.J. Alumbaugh Cc: Yu Zhao Signed-off-by: Andrew Morton --- mm/vmscan.c | 250 ++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 142 insertions(+), 108 deletions(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index 1be9120349f8..796d4ca65e97 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4705,6 +4705,148 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw) mem_cgroup_unlock_pages(); } +/****************************************************************************** + * memcg LRU + ******************************************************************************/ + +/* see the comment on MEMCG_NR_GENS */ +enum { + MEMCG_LRU_NOP, + MEMCG_LRU_HEAD, + MEMCG_LRU_TAIL, + MEMCG_LRU_OLD, + MEMCG_LRU_YOUNG, +}; + +#ifdef CONFIG_MEMCG + +static int lru_gen_memcg_seg(struct lruvec *lruvec) +{ + return READ_ONCE(lruvec->lrugen.seg); +} + +static void lru_gen_rotate_memcg(struct lruvec *lruvec, int op) +{ + int seg; + int old, new; + int bin = get_random_u32_below(MEMCG_NR_BINS); + struct pglist_data *pgdat = lruvec_pgdat(lruvec); + + spin_lock(&pgdat->memcg_lru.lock); + + VM_WARN_ON_ONCE(hlist_nulls_unhashed(&lruvec->lrugen.list)); + + seg = 0; + new = old = lruvec->lrugen.gen; + + /* see the comment on MEMCG_NR_GENS */ + if (op == MEMCG_LRU_HEAD) + seg = MEMCG_LRU_HEAD; + else if (op == MEMCG_LRU_TAIL) + seg = MEMCG_LRU_TAIL; + else if (op == MEMCG_LRU_OLD) + new = get_memcg_gen(pgdat->memcg_lru.seq); + else if (op == MEMCG_LRU_YOUNG) + new = get_memcg_gen(pgdat->memcg_lru.seq + 1); + else + VM_WARN_ON_ONCE(true); + + hlist_nulls_del_rcu(&lruvec->lrugen.list); + + if (op == MEMCG_LRU_HEAD || op == MEMCG_LRU_OLD) + hlist_nulls_add_head_rcu(&lruvec->lrugen.list, &pgdat->memcg_lru.fifo[new][bin]); + else + hlist_nulls_add_tail_rcu(&lruvec->lrugen.list, &pgdat->memcg_lru.fifo[new][bin]); + + pgdat->memcg_lru.nr_memcgs[old]--; + pgdat->memcg_lru.nr_memcgs[new]++; + + lruvec->lrugen.gen = new; + WRITE_ONCE(lruvec->lrugen.seg, seg); + + if (!pgdat->memcg_lru.nr_memcgs[old] && old == get_memcg_gen(pgdat->memcg_lru.seq)) + WRITE_ONCE(pgdat->memcg_lru.seq, pgdat->memcg_lru.seq + 1); + + spin_unlock(&pgdat->memcg_lru.lock); +} + +void lru_gen_online_memcg(struct mem_cgroup *memcg) +{ + int gen; + int nid; + int bin = get_random_u32_below(MEMCG_NR_BINS); + + for_each_node(nid) { + struct pglist_data *pgdat = NODE_DATA(nid); + struct lruvec *lruvec = get_lruvec(memcg, nid); + + spin_lock(&pgdat->memcg_lru.lock); + + VM_WARN_ON_ONCE(!hlist_nulls_unhashed(&lruvec->lrugen.list)); + + gen = get_memcg_gen(pgdat->memcg_lru.seq); + + hlist_nulls_add_tail_rcu(&lruvec->lrugen.list, &pgdat->memcg_lru.fifo[gen][bin]); + pgdat->memcg_lru.nr_memcgs[gen]++; + + lruvec->lrugen.gen = gen; + + spin_unlock(&pgdat->memcg_lru.lock); + } +} + +void lru_gen_offline_memcg(struct mem_cgroup *memcg) +{ + int nid; + + for_each_node(nid) { + struct lruvec *lruvec = get_lruvec(memcg, nid); + + lru_gen_rotate_memcg(lruvec, MEMCG_LRU_OLD); + } +} + +void lru_gen_release_memcg(struct mem_cgroup *memcg) +{ + int gen; + int nid; + + for_each_node(nid) { + struct pglist_data *pgdat = NODE_DATA(nid); + struct lruvec *lruvec = get_lruvec(memcg, nid); + + spin_lock(&pgdat->memcg_lru.lock); + + VM_WARN_ON_ONCE(hlist_nulls_unhashed(&lruvec->lrugen.list)); + + gen = lruvec->lrugen.gen; + + hlist_nulls_del_rcu(&lruvec->lrugen.list); + pgdat->memcg_lru.nr_memcgs[gen]--; + + if (!pgdat->memcg_lru.nr_memcgs[gen] && gen == get_memcg_gen(pgdat->memcg_lru.seq)) + WRITE_ONCE(pgdat->memcg_lru.seq, pgdat->memcg_lru.seq + 1); + + spin_unlock(&pgdat->memcg_lru.lock); + } +} + +void lru_gen_soft_reclaim(struct lruvec *lruvec) +{ + /* see the comment on MEMCG_NR_GENS */ + if (lru_gen_memcg_seg(lruvec) != MEMCG_LRU_HEAD) + lru_gen_rotate_memcg(lruvec, MEMCG_LRU_HEAD); +} + +#else /* !CONFIG_MEMCG */ + +static int lru_gen_memcg_seg(struct lruvec *lruvec) +{ + return 0; +} + +#endif + /****************************************************************************** * the eviction ******************************************************************************/ @@ -5397,53 +5539,6 @@ done: pgdat->kswapd_failures = 0; } -#ifdef CONFIG_MEMCG -void lru_gen_rotate_memcg(struct lruvec *lruvec, int op) -{ - int seg; - int old, new; - int bin = get_random_u32_below(MEMCG_NR_BINS); - struct pglist_data *pgdat = lruvec_pgdat(lruvec); - - spin_lock(&pgdat->memcg_lru.lock); - - VM_WARN_ON_ONCE(hlist_nulls_unhashed(&lruvec->lrugen.list)); - - seg = 0; - new = old = lruvec->lrugen.gen; - - /* see the comment on MEMCG_NR_GENS */ - if (op == MEMCG_LRU_HEAD) - seg = MEMCG_LRU_HEAD; - else if (op == MEMCG_LRU_TAIL) - seg = MEMCG_LRU_TAIL; - else if (op == MEMCG_LRU_OLD) - new = get_memcg_gen(pgdat->memcg_lru.seq); - else if (op == MEMCG_LRU_YOUNG) - new = get_memcg_gen(pgdat->memcg_lru.seq + 1); - else - VM_WARN_ON_ONCE(true); - - hlist_nulls_del_rcu(&lruvec->lrugen.list); - - if (op == MEMCG_LRU_HEAD || op == MEMCG_LRU_OLD) - hlist_nulls_add_head_rcu(&lruvec->lrugen.list, &pgdat->memcg_lru.fifo[new][bin]); - else - hlist_nulls_add_tail_rcu(&lruvec->lrugen.list, &pgdat->memcg_lru.fifo[new][bin]); - - pgdat->memcg_lru.nr_memcgs[old]--; - pgdat->memcg_lru.nr_memcgs[new]++; - - lruvec->lrugen.gen = new; - WRITE_ONCE(lruvec->lrugen.seg, seg); - - if (!pgdat->memcg_lru.nr_memcgs[old] && old == get_memcg_gen(pgdat->memcg_lru.seq)) - WRITE_ONCE(pgdat->memcg_lru.seq, pgdat->memcg_lru.seq + 1); - - spin_unlock(&pgdat->memcg_lru.lock); -} -#endif - /****************************************************************************** * state change ******************************************************************************/ @@ -6086,67 +6181,6 @@ void lru_gen_exit_memcg(struct mem_cgroup *memcg) } } -void lru_gen_online_memcg(struct mem_cgroup *memcg) -{ - int gen; - int nid; - int bin = get_random_u32_below(MEMCG_NR_BINS); - - for_each_node(nid) { - struct pglist_data *pgdat = NODE_DATA(nid); - struct lruvec *lruvec = get_lruvec(memcg, nid); - - spin_lock(&pgdat->memcg_lru.lock); - - VM_WARN_ON_ONCE(!hlist_nulls_unhashed(&lruvec->lrugen.list)); - - gen = get_memcg_gen(pgdat->memcg_lru.seq); - - hlist_nulls_add_tail_rcu(&lruvec->lrugen.list, &pgdat->memcg_lru.fifo[gen][bin]); - pgdat->memcg_lru.nr_memcgs[gen]++; - - lruvec->lrugen.gen = gen; - - spin_unlock(&pgdat->memcg_lru.lock); - } -} - -void lru_gen_offline_memcg(struct mem_cgroup *memcg) -{ - int nid; - - for_each_node(nid) { - struct lruvec *lruvec = get_lruvec(memcg, nid); - - lru_gen_rotate_memcg(lruvec, MEMCG_LRU_OLD); - } -} - -void lru_gen_release_memcg(struct mem_cgroup *memcg) -{ - int gen; - int nid; - - for_each_node(nid) { - struct pglist_data *pgdat = NODE_DATA(nid); - struct lruvec *lruvec = get_lruvec(memcg, nid); - - spin_lock(&pgdat->memcg_lru.lock); - - VM_WARN_ON_ONCE(hlist_nulls_unhashed(&lruvec->lrugen.list)); - - gen = lruvec->lrugen.gen; - - hlist_nulls_del_rcu(&lruvec->lrugen.list); - pgdat->memcg_lru.nr_memcgs[gen]--; - - if (!pgdat->memcg_lru.nr_memcgs[gen] && gen == get_memcg_gen(pgdat->memcg_lru.seq)) - WRITE_ONCE(pgdat->memcg_lru.seq, pgdat->memcg_lru.seq + 1); - - spin_unlock(&pgdat->memcg_lru.lock); - } -} - #endif /* CONFIG_MEMCG */ static int __init init_lru_gen(void) -- cgit