From c8dad2bb6307f5b00f804a686917105206a4d5c9 Mon Sep 17 00:00:00 2001 From: Jan Blunck Date: Wed, 7 Jan 2009 18:07:53 -0800 Subject: [PATCH] memcg: reduce size of mem_cgroup by using nr_cpu_ids As Jan Blunck pointed out, allocating per-cpu stat for memcg to the size of NR_CPUS is not good. This patch changes mem_cgroup's cpustat allocation not based on NR_CPUS but based on nr_cpu_ids. Reviewed-by: Li Zefan Signed-off-by: KAMEZAWA Hiroyuki Cc: Li Zefan Cc: Balbir Singh Cc: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 49234d93988a..e00f25e6545f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -60,7 +60,7 @@ struct mem_cgroup_stat_cpu { } ____cacheline_aligned_in_smp; struct mem_cgroup_stat { - struct mem_cgroup_stat_cpu cpustat[NR_CPUS]; + struct mem_cgroup_stat_cpu cpustat[0]; }; /* @@ -129,11 +129,10 @@ struct mem_cgroup { int prev_priority; /* for recording reclaim priority */ /* - * statistics. + * statistics. This must be placed at the end of memcg. */ struct mem_cgroup_stat stat; }; -static struct mem_cgroup init_mem_cgroup; enum charge_type { MEM_CGROUP_CHARGE_TYPE_CACHE = 0, @@ -1293,23 +1292,30 @@ static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) kfree(mem->info.nodeinfo[node]); } +static int mem_cgroup_size(void) +{ + int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu); + return sizeof(struct mem_cgroup) + cpustat_size; +} + static struct mem_cgroup *mem_cgroup_alloc(void) { struct mem_cgroup *mem; + int size = mem_cgroup_size(); - if (sizeof(*mem) < PAGE_SIZE) - mem = kmalloc(sizeof(*mem), GFP_KERNEL); + if (size < PAGE_SIZE) + mem = kmalloc(size, GFP_KERNEL); else - mem = vmalloc(sizeof(*mem)); + mem = vmalloc(size); if (mem) - memset(mem, 0, sizeof(*mem)); + memset(mem, 0, size); return mem; } static void mem_cgroup_free(struct mem_cgroup *mem) { - if (sizeof(*mem) < PAGE_SIZE) + if (mem_cgroup_size() < PAGE_SIZE) kfree(mem); else vfree(mem); @@ -1322,13 +1328,9 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) struct mem_cgroup *mem; int node; - if (unlikely((cont->parent) == NULL)) { - mem = &init_mem_cgroup; - } else { - mem = mem_cgroup_alloc(); - if (!mem) - return ERR_PTR(-ENOMEM); - } + mem = mem_cgroup_alloc(); + if (!mem) + return ERR_PTR(-ENOMEM); res_counter_init(&mem->res); @@ -1340,8 +1342,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) free_out: for_each_node_state(node, N_POSSIBLE) free_mem_cgroup_per_zone_info(mem, node); - if (cont->parent != NULL) - mem_cgroup_free(mem); + mem_cgroup_free(mem); return ERR_PTR(-ENOMEM); } -- GitLab