Now that __smp_call_function_single is available for all builds and uses llists to queue up items without taking a lock or disabling interrupts there is no need to wrap around it in the block code.
Signed-off-by: Christoph Hellwig <[email protected]> --- block/blk-mq-cpu.c | 31 ------------------------ block/blk-mq.c | 68 +++++++++------------------------------------------- block/blk-mq.h | 1 - 3 files changed, 11 insertions(+), 89 deletions(-) diff --git a/block/blk-mq-cpu.c b/block/blk-mq-cpu.c index f8ea39d..4f0c352 100644 --- a/block/blk-mq-cpu.c +++ b/block/blk-mq-cpu.c @@ -28,32 +28,6 @@ static int __cpuinit blk_mq_main_cpu_notify(struct notifier_block *self, return NOTIFY_OK; } -static void __cpuinit blk_mq_cpu_notify(void *data, unsigned long action, - unsigned int cpu) -{ - if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { - /* - * If the CPU goes away, ensure that we run any pending - * completions. - */ - struct llist_node *node; - struct request *rq; - - local_irq_disable(); - - node = llist_del_all(&per_cpu(ipi_lists, cpu)); - while (node) { - struct llist_node *next = node->next; - - rq = llist_entry(node, struct request, ll_list); - __blk_mq_end_io(rq, rq->errors); - node = next; - } - - local_irq_enable(); - } -} - static struct notifier_block __cpuinitdata blk_mq_main_cpu_notifier = { .notifier_call = blk_mq_main_cpu_notify, }; @@ -82,12 +56,7 @@ void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier, notifier->data = data; } -static struct blk_mq_cpu_notifier __cpuinitdata cpu_notifier = { - .notify = blk_mq_cpu_notify, -}; - void __init blk_mq_cpu_init(void) { register_hotcpu_notifier(&blk_mq_main_cpu_notifier); - blk_mq_register_cpu_notifier(&cpu_notifier); } diff --git a/block/blk-mq.c b/block/blk-mq.c index d43a7e8..0b2b487 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -27,8 +27,6 @@ static LIST_HEAD(all_q_list); static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx); -DEFINE_PER_CPU(struct llist_head, ipi_lists); - static struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q, unsigned int cpu) { @@ -318,55 +316,12 @@ void __blk_mq_end_io(struct request *rq, int error) blk_mq_complete_request(rq, error); } -#if defined(CONFIG_SMP) - -/* - * Called with interrupts disabled. - */ -static void ipi_end_io(void *data) +static void blk_mq_end_io_remote(void *data) { - struct llist_head *list = &per_cpu(ipi_lists, smp_processor_id()); - struct llist_node *entry, *next; - struct request *rq; - - entry = llist_del_all(list); - - while (entry) { - next = entry->next; - rq = llist_entry(entry, struct request, ll_list); - __blk_mq_end_io(rq, rq->errors); - entry = next; - } -} - -static int ipi_remote_cpu(struct blk_mq_ctx *ctx, const int cpu, - struct request *rq, const int error) -{ - struct call_single_data *data = &rq->csd; - - rq->errors = error; - rq->ll_list.next = NULL; - - /* - * If the list is non-empty, an existing IPI must already - * be "in flight". If that is the case, we need not schedule - * a new one. - */ - if (llist_add(&rq->ll_list, &per_cpu(ipi_lists, ctx->cpu))) { - data->func = ipi_end_io; - data->flags = 0; - __smp_call_function_single(ctx->cpu, data, 0); - } + struct request *rq = data; - return true; + __blk_mq_end_io(rq, rq->errors); } -#else /* CONFIG_SMP */ -static int ipi_remote_cpu(struct blk_mq_ctx *ctx, const int cpu, - struct request *rq, const int error) -{ - return false; -} -#endif /* * End IO on this request on a multiqueue enabled driver. We'll either do @@ -382,11 +337,15 @@ void blk_mq_end_io(struct request *rq, int error) return __blk_mq_end_io(rq, error); cpu = get_cpu(); - - if (cpu == ctx->cpu || !cpu_online(ctx->cpu) || - !ipi_remote_cpu(ctx, cpu, rq, error)) + if (cpu != ctx->cpu && cpu_online(ctx->cpu)) { + rq->errors = error; + rq->csd.func = blk_mq_end_io_remote; + rq->csd.info = rq; + rq->csd.flags = 0; + __smp_call_function_single(ctx->cpu, &rq->csd, 0); + } else { __blk_mq_end_io(rq, error); - + } put_cpu(); } EXPORT_SYMBOL(blk_mq_end_io); @@ -1465,11 +1424,6 @@ static int __cpuinit blk_mq_queue_reinit_notify(struct notifier_block *nb, static int __init blk_mq_init(void) { - unsigned int i; - - for_each_possible_cpu(i) - init_llist_head(&per_cpu(ipi_lists, i)); - blk_mq_cpu_init(); /* Must be called after percpu_counter_hotcpu_callback() */ diff --git a/block/blk-mq.h b/block/blk-mq.h index 52bf1f9..5761eed 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -38,7 +38,6 @@ void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier, void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier); void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier); void blk_mq_cpu_init(void); -DECLARE_PER_CPU(struct llist_head, ipi_lists); /* * CPU -> queue mappings -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
