From 2cd21c89800c2203331e5564df2155757ded2e86 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 29 Apr 2021 22:56:29 -0700 Subject: [PATCH] mm: memcontrol: consolidate lruvec stat flushing MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit There are two functions to flush the per-cpu data of an lruvec into the rest of the cgroup tree: when the cgroup is being freed, and when a CPU disappears during hotplug. The difference is whether all CPUs or just one is being collected, but the rest of the flushing code is the same. Merge them into one function and share the common code. Link: https://lkml.kernel.org/r/20210209163304.77088-8-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Reviewed-by: Shakeel Butt Acked-by: Michal Hocko Acked-by: Roman Gushchin Cc: Michal Koutný Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 74 +++++++++++++++++++------------------------------ 1 file changed, 28 insertions(+), 46 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b323588223ac..5582e1531b43 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2364,39 +2364,39 @@ static void drain_all_stock(struct mem_cgroup *root_memcg) mutex_unlock(&percpu_charge_mutex); } -static int memcg_hotplug_cpu_dead(unsigned int cpu) +static void memcg_flush_lruvec_page_state(struct mem_cgroup *memcg, int cpu) { - struct memcg_stock_pcp *stock; - struct mem_cgroup *memcg; - - stock = &per_cpu(memcg_stock, cpu); - drain_stock(stock); + int nid; - for_each_mem_cgroup(memcg) { + for_each_node(nid) { + struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid]; + unsigned long stat[NR_VM_NODE_STAT_ITEMS]; + struct batched_lruvec_stat *lstatc; int i; + lstatc = per_cpu_ptr(pn->lruvec_stat_cpu, cpu); for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { - int nid; + stat[i] = lstatc->count[i]; + lstatc->count[i] = 0; + } - for_each_node(nid) { - struct batched_lruvec_stat *lstatc; - struct mem_cgroup_per_node *pn; - long x; + do { + for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) + atomic_long_add(stat[i], &pn->lruvec_stat[i]); + } while ((pn = parent_nodeinfo(pn, nid))); + } +} - pn = memcg->nodeinfo[nid]; - lstatc = per_cpu_ptr(pn->lruvec_stat_cpu, cpu); +static int memcg_hotplug_cpu_dead(unsigned int cpu) +{ + struct memcg_stock_pcp *stock; + struct mem_cgroup *memcg; - x = lstatc->count[i]; - lstatc->count[i] = 0; + stock = &per_cpu(memcg_stock, cpu); + drain_stock(stock); - if (x) { - do { - atomic_long_add(x, &pn->lruvec_stat[i]); - } while ((pn = parent_nodeinfo(pn, nid))); - } - } - } - } + for_each_mem_cgroup(memcg) + memcg_flush_lruvec_page_state(memcg, cpu); return 0; } @@ -3583,27 +3583,6 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, } } -static void memcg_flush_lruvec_page_state(struct mem_cgroup *memcg) -{ - int node; - - for_each_node(node) { - struct mem_cgroup_per_node *pn = memcg->nodeinfo[node]; - unsigned long stat[NR_VM_NODE_STAT_ITEMS] = { 0 }; - struct mem_cgroup_per_node *pi; - int cpu, i; - - for_each_online_cpu(cpu) - for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) - stat[i] += per_cpu( - pn->lruvec_stat_cpu->count[i], cpu); - - for (pi = pn; pi; pi = parent_nodeinfo(pi, node)) - for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) - atomic_long_add(stat[i], &pi->lruvec_stat[i]); - } -} - #ifdef CONFIG_MEMCG_KMEM static int memcg_online_kmem(struct mem_cgroup *memcg) { @@ -5139,12 +5118,15 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg) static void mem_cgroup_free(struct mem_cgroup *memcg) { + int cpu; + memcg_wb_domain_exit(memcg); /* * Flush percpu lruvec stats to guarantee the value * correctness on parent's and all ancestor levels. */ - memcg_flush_lruvec_page_state(memcg); + for_each_online_cpu(cpu) + memcg_flush_lruvec_page_state(memcg, cpu); __mem_cgroup_free(memcg); } -- 2.20.1