diff options
| -rw-r--r-- | block/blk-mq-cpumap.c | 9 | ||||
| -rw-r--r-- | block/blk-mq.c | 59 | ||||
| -rw-r--r-- | block/blk-mq.h | 3 |
3 files changed, 52 insertions, 19 deletions
diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c index 1e28ddb..8764c24 100644 --- a/block/blk-mq-cpumap.c +++ b/block/blk-mq-cpumap.c @@ -31,7 +31,8 @@ static int get_first_sibling(unsigned int cpu) return cpu; } -int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues) +int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues, + const struct cpumask *online_mask) { unsigned int i, nr_cpus, nr_uniq_cpus, queue, first_sibling; cpumask_var_t cpus; @@ -41,7 +42,7 @@ int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues) cpumask_clear(cpus); nr_cpus = nr_uniq_cpus = 0; - for_each_online_cpu(i) { + for_each_cpu(i, online_mask) { nr_cpus++; first_sibling = get_first_sibling(i); if (!cpumask_test_cpu(first_sibling, cpus)) @@ -51,7 +52,7 @@ int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues) queue = 0; for_each_possible_cpu(i) { - if (!cpu_online(i)) { + if (!cpumask_test_cpu(i, online_mask)) { map[i] = 0; continue; } @@ -95,7 +96,7 @@ unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set) if (!map) return NULL; - if (!blk_mq_update_queue_map(map, set->nr_hw_queues)) + if (!blk_mq_update_queue_map(map, set->nr_hw_queues, cpu_online_mask)) return map; kfree(map); diff --git a/block/blk-mq.c b/block/blk-mq.c index 3a39184..a5dbd06 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1789,7 +1789,8 @@ static void blk_mq_init_cpu_queues(struct request_queue *q, } } -static void blk_mq_map_swqueue(struct request_queue *q) +static void blk_mq_map_swqueue(struct request_queue *q, + const struct cpumask *online_mask) { unsigned int i; struct blk_mq_hw_ctx *hctx; @@ -1806,7 +1807,7 @@ static void blk_mq_map_swqueue(struct request_queue *q) */ queue_for_each_ctx(q, ctx, i) { /* If the cpu isn't online, the cpu is mapped to first hctx */ - if (!cpu_online(i)) + if (!cpumask_test_cpu(i, online_mask)) continue; hctx = q->mq_ops->map_queue(q, i); @@ -1852,7 +1853,7 @@ static void blk_mq_map_swqueue(struct request_queue *q) } queue_for_each_ctx(q, ctx, i) { - if (!cpu_online(i)) + if (!cpumask_test_cpu(i, online_mask)) continue; hctx = q->mq_ops->map_queue(q, i); @@ -2037,13 +2038,15 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, if (blk_mq_init_hw_queues(q, set)) goto err_hctxs; + get_online_cpus(); mutex_lock(&all_q_mutex); list_add_tail(&q->all_q_node, &all_q_list); blk_mq_add_queue_tag_set(set, q); - blk_mq_map_swqueue(q); + blk_mq_map_swqueue(q, cpu_online_mask); mutex_unlock(&all_q_mutex); + put_online_cpus(); return q; @@ -2080,13 +2083,14 @@ void blk_mq_free_queue(struct request_queue *q) } /* Basically redo blk_mq_init_queue with queue frozen */ -static void blk_mq_queue_reinit(struct request_queue *q) +static void blk_mq_queue_reinit(struct request_queue *q, + const struct cpumask *online_mask) { WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth)); blk_mq_sysfs_unregister(q); - blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues); + blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues, online_mask); /* * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe @@ -2094,7 +2098,7 @@ static void blk_mq_queue_reinit(struct request_queue *q) * involves free and re-allocate memory, worthy doing?) */ - blk_mq_map_swqueue(q); + blk_mq_map_swqueue(q, online_mask); blk_mq_sysfs_register(q); } @@ -2103,16 +2107,43 @@ static int blk_mq_queue_reinit_notify(struct notifier_block *nb, unsigned long action, void *hcpu) { struct request_queue *q; + int cpu = (unsigned long)hcpu; + /* + * New online cpumask which is going to be set in this hotplug event. + * Declare this cpumasks as global as cpu-hotplug operation is invoked + * one-by-one and dynamically allocating this could result in a failure. + */ + static struct cpumask online_new; /* - * Before new mappings are established, hotadded cpu might already - * start handling requests. This doesn't break anything as we map - * offline CPUs to first hardware queue. We will re-init the queue - * below to get optimal settings. + * Before hotadded cpu starts handling requests, new mappings must + * be established. Otherwise, these requests in hw queue might + * never be dispatched. + * + * For example, there is a single hw queue (hctx) and two CPU queues + * (ctx0 for CPU0, and ctx1 for CPU1). + * + * Now CPU1 is just onlined and a request is inserted into + * ctx1->rq_list and set bit0 in pending bitmap as ctx1->index_hw is + * still zero. + * + * And then while running hw queue, flush_busy_ctxs() finds bit0 is + * set in pending bitmap and tries to retrieve requests in + * hctx->ctxs[0]->rq_list. But htx->ctxs[0] is a pointer to ctx0, + * so the request in ctx1->rq_list is ignored. */ - if (action != CPU_DEAD && action != CPU_DEAD_FROZEN && - action != CPU_ONLINE && action != CPU_ONLINE_FROZEN) + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_DEAD: + case CPU_UP_CANCELED: + cpumask_copy(&online_new, cpu_online_mask); + break; + case CPU_UP_PREPARE: + cpumask_copy(&online_new, cpu_online_mask); + cpumask_set_cpu(cpu, &online_new); + break; + default: return NOTIFY_OK; + } mutex_lock(&all_q_mutex); @@ -2136,7 +2167,7 @@ static int blk_mq_queue_reinit_notify(struct notifier_block *nb, } list_for_each_entry(q, &all_q_list, all_q_node) - blk_mq_queue_reinit(q); + blk_mq_queue_reinit(q, &online_new); list_for_each_entry(q, &all_q_list, all_q_node) blk_mq_unfreeze_queue(q); diff --git a/block/blk-mq.h b/block/blk-mq.h index 6a48c4c..f4fea79 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -51,7 +51,8 @@ void blk_mq_disable_hotplug(void); * CPU -> queue mappings */ extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set); -extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues); +extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues, + const struct cpumask *online_mask); extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int); /* |
