diff options
| -rw-r--r-- | mm/memcontrol.c | 54 |
1 files changed, 38 insertions, 16 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0b1a32cbd74d..c39a177bb641 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -359,7 +359,7 @@ enum charge_type { static void mem_cgroup_get(struct mem_cgroup *mem); static void mem_cgroup_put(struct mem_cgroup *mem); static struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *mem); -static void drain_all_stock_async(void); +static void drain_all_stock_async(struct mem_cgroup *mem); static struct mem_cgroup_per_zone * mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid) @@ -1671,7 +1671,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, if (victim == root_mem) { loop++; if (loop >= 1) - drain_all_stock_async(); + drain_all_stock_async(root_mem); if (loop >= 2) { /* * If we have not been able to reclaim @@ -1934,9 +1934,11 @@ struct memcg_stock_pcp { struct mem_cgroup *cached; /* this never be root cgroup */ unsigned int nr_pages; struct work_struct work; + unsigned long flags; +#define FLUSHING_CACHED_CHARGE (0) }; static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); -static atomic_t memcg_drain_count; +static DEFINE_MUTEX(percpu_charge_mutex); /* * Try to consume stocked charge on this cpu. If success, one page is consumed @@ -1984,6 +1986,7 @@ static void drain_local_stock(struct work_struct *dummy) { struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock); drain_stock(stock); + clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); } /* @@ -2008,26 +2011,45 @@ static void refill_stock(struct mem_cgroup *mem, unsigned int nr_pages) * expects some charges will be back to res_counter later but cannot wait for * it. */ -static void drain_all_stock_async(void) +static void drain_all_stock_async(struct mem_cgroup *root_mem) { - int cpu; - /* This function is for scheduling "drain" in asynchronous way. - * The result of "drain" is not directly handled by callers. Then, - * if someone is calling drain, we don't have to call drain more. - * Anyway, WORK_STRUCT_PENDING check in queue_work_on() will catch if - * there is a race. We just do loose check here. + int cpu, curcpu; + /* + * If someone calls draining, avoid adding more kworker runs. */ - if (atomic_read(&memcg_drain_count)) + if (!mutex_trylock(&percpu_charge_mutex)) return; /* Notify other cpus that system-wide "drain" is running */ - atomic_inc(&memcg_drain_count); get_online_cpus(); + /* + * Get a hint for avoiding draining charges on the current cpu, + * which must be exhausted by our charging. It is not required that + * this be a precise check, so we use raw_smp_processor_id() instead of + * getcpu()/putcpu(). + */ + curcpu = raw_smp_processor_id(); for_each_online_cpu(cpu) { struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); - schedule_work_on(cpu, &stock->work); + struct mem_cgroup *mem; + + if (cpu == curcpu) + continue; + + mem = stock->cached; + if (!mem) + continue; + if (mem != root_mem) { + if (!root_mem->use_hierarchy) + continue; + /* check whether "mem" is under tree of "root_mem" */ + if (!css_is_ancestor(&mem->css, &root_mem->css)) + continue; + } + if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) + schedule_work_on(cpu, &stock->work); } put_online_cpus(); - atomic_dec(&memcg_drain_count); + mutex_unlock(&percpu_charge_mutex); /* We don't wait for flush_work */ } @@ -2035,9 +2057,9 @@ static void drain_all_stock_async(void) static void drain_all_stock_sync(void) { /* called when force_empty is called */ - atomic_inc(&memcg_drain_count); + mutex_lock(&percpu_charge_mutex); schedule_on_each_cpu(drain_local_stock); - atomic_dec(&memcg_drain_count); + mutex_unlock(&percpu_charge_mutex); } /* |