Replace the block-mq notifier list management with the multi instance facility in the cpu hotplug state machine. Signed-off-by: Thomas Gleixner Cc: Jens Axboe Cc: Peter Zijlstra Cc: linux-block@vger.kernel.org Cc: rt@linutronix.de Cc: Christoph Hellwing --- block/Makefile | 2 - block/blk-mq-cpu.c | 67 ------------------------------------------------- block/blk-mq.c | 36 +++++++++----------------- block/blk-mq.h | 7 ----- include/linux/blk-mq.h | 8 ----- 5 files changed, 15 insertions(+), 105 deletions(-) --- a/block/Makefile +++ b/block/Makefile @@ -6,7 +6,7 @@ obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-flush.o blk-settings.o blk-ioc.o blk-map.o \ blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \ blk-lib.o blk-mq.o blk-mq-tag.o \ - blk-mq-sysfs.o blk-mq-cpu.o blk-mq-cpumap.o ioctl.o \ + blk-mq-sysfs.o blk-mq-cpumap.o ioctl.o \ genhd.o scsi_ioctl.o partition-generic.o ioprio.o \ badblocks.o partitions/ --- a/block/blk-mq-cpu.c +++ /dev/null @@ -1,67 +0,0 @@ -/* - * CPU notifier helper code for blk-mq - * - * Copyright (C) 2013-2014 Jens Axboe - */ -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include "blk-mq.h" - -static LIST_HEAD(blk_mq_cpu_notify_list); -static DEFINE_RAW_SPINLOCK(blk_mq_cpu_notify_lock); - -static int blk_mq_main_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - unsigned int cpu = (unsigned long) hcpu; - struct blk_mq_cpu_notifier *notify; - int ret = NOTIFY_OK; - - raw_spin_lock(&blk_mq_cpu_notify_lock); - - list_for_each_entry(notify, &blk_mq_cpu_notify_list, list) { - ret = notify->notify(notify->data, action, cpu); - if (ret != NOTIFY_OK) - break; - } - - raw_spin_unlock(&blk_mq_cpu_notify_lock); - return ret; -} - -void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier) -{ - BUG_ON(!notifier->notify); - - raw_spin_lock(&blk_mq_cpu_notify_lock); - list_add_tail(¬ifier->list, &blk_mq_cpu_notify_list); - raw_spin_unlock(&blk_mq_cpu_notify_lock); -} - -void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier) -{ - raw_spin_lock(&blk_mq_cpu_notify_lock); - list_del(¬ifier->list); - raw_spin_unlock(&blk_mq_cpu_notify_lock); -} - -void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier, - int (*fn)(void *, unsigned long, unsigned int), - void *data) -{ - notifier->notify = fn; - notifier->data = data; -} - -void __init blk_mq_cpu_init(void) -{ - hotcpu_notifier(blk_mq_main_cpu_notify, 0); -} --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1575,11 +1575,13 @@ static struct blk_mq_tags *blk_mq_init_r * software queue to the hw queue dispatch list, and ensure that it * gets run. */ -static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu) +static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) { + struct blk_mq_hw_ctx *hctx; struct blk_mq_ctx *ctx; LIST_HEAD(tmp); + hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); ctx = __blk_mq_get_ctx(hctx->queue, cpu); spin_lock(&ctx->lock); @@ -1590,30 +1592,20 @@ static int blk_mq_hctx_cpu_offline(struc spin_unlock(&ctx->lock); if (list_empty(&tmp)) - return NOTIFY_OK; + return 0; spin_lock(&hctx->lock); list_splice_tail_init(&tmp, &hctx->dispatch); spin_unlock(&hctx->lock); blk_mq_run_hw_queue(hctx, true); - return NOTIFY_OK; + return 0; } -static int blk_mq_hctx_notify(void *data, unsigned long action, - unsigned int cpu) +static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) { - struct blk_mq_hw_ctx *hctx = data; - - if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) - return blk_mq_hctx_cpu_offline(hctx, cpu); - - /* - * In case of CPU online, tags may be reallocated - * in blk_mq_map_swqueue() after mapping is updated. - */ - - return NOTIFY_OK; + cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, + &hctx->cpuhp_dead); } /* hctx->ctxs will be freed in queue's release handler */ @@ -1633,7 +1625,7 @@ static void blk_mq_exit_hctx(struct requ if (set->ops->exit_hctx) set->ops->exit_hctx(hctx, hctx_idx); - blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); + blk_mq_remove_cpuhp(hctx); blk_free_flush_queue(hctx->fq); sbitmap_free(&hctx->ctx_map); } @@ -1680,9 +1672,7 @@ static int blk_mq_init_hctx(struct reque hctx->queue_num = hctx_idx; hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; - blk_mq_init_cpu_notifier(&hctx->cpu_notifier, - blk_mq_hctx_notify, hctx); - blk_mq_register_cpu_notifier(&hctx->cpu_notifier); + cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); hctx->tags = set->tags[hctx_idx]; @@ -1727,8 +1717,7 @@ static int blk_mq_init_hctx(struct reque free_ctxs: kfree(hctx->ctxs); unregister_cpu_notifier: - blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); - + blk_mq_remove_cpuhp(hctx); return -1; } @@ -2390,7 +2379,8 @@ void blk_mq_enable_hotplug(void) static int __init blk_mq_init(void) { - blk_mq_cpu_init(); + cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, + blk_mq_hctx_notify_dead); hotcpu_notifier(blk_mq_queue_reinit_notify, 0); --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -32,13 +32,6 @@ void blk_mq_wake_waiters(struct request_ /* * CPU hotplug helpers */ -struct blk_mq_cpu_notifier; -void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier, - int (*fn)(void *, unsigned long, unsigned int), - void *data); -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); void blk_mq_enable_hotplug(void); void blk_mq_disable_hotplug(void); --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -7,12 +7,6 @@ struct blk_mq_tags; struct blk_flush_queue; -struct blk_mq_cpu_notifier { - struct list_head list; - void *data; - int (*notify)(void *data, unsigned long action, unsigned int cpu); -}; - struct blk_mq_hw_ctx { struct { spinlock_t lock; @@ -53,7 +47,7 @@ struct blk_mq_hw_ctx { struct delayed_work delay_work; - struct blk_mq_cpu_notifier cpu_notifier; + struct hlist_node cpuhp_dead; struct kobject kobj; unsigned long poll_considered;