diff options
Diffstat (limited to 'drivers/block/aoe/aoecmd.c')
| -rw-r--r-- | drivers/block/aoe/aoecmd.c | 156 |
1 files changed, 128 insertions, 28 deletions
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c index fc803ecbbce4..99cb944a002d 100644 --- a/drivers/block/aoe/aoecmd.c +++ b/drivers/block/aoe/aoecmd.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2012 Coraid, Inc. See COPYING for GPL terms. */ +/* Copyright (c) 2013 Coraid, Inc. See COPYING for GPL terms. */ /* * aoecmd.c * Filesystem request handling methods @@ -35,14 +35,27 @@ module_param(aoe_maxout, int, 0644); MODULE_PARM_DESC(aoe_maxout, "Only aoe_maxout outstanding packets for every MAC on eX.Y."); -static wait_queue_head_t ktiowq; -static struct ktstate kts; +/* The number of online cpus during module initialization gives us a + * convenient heuristic cap on the parallelism used for ktio threads + * doing I/O completion. It is not important that the cap equal the + * actual number of running CPUs at any given time, but because of CPU + * hotplug, we take care to use ncpus instead of using + * num_online_cpus() after module initialization. + */ +static int ncpus; + +/* mutex lock used for synchronization while thread spawning */ +static DEFINE_MUTEX(ktio_spawn_lock); + +static wait_queue_head_t *ktiowq; +static struct ktstate *kts; /* io completion queue */ -static struct { +struct iocq_ktio { struct list_head head; spinlock_t lock; -} iocq; +}; +static struct iocq_ktio *iocq; static struct page *empty_page; @@ -1278,23 +1291,36 @@ out: * Returns true iff responses needing processing remain. */ static int -ktio(void) +ktio(int id) { struct frame *f; struct list_head *pos; int i; + int actual_id; for (i = 0; ; ++i) { if (i == MAXIOC) return 1; - if (list_empty(&iocq.head)) + if (list_empty(&iocq[id].head)) return 0; - pos = iocq.head.next; + pos = iocq[id].head.next; list_del(pos); - spin_unlock_irq(&iocq.lock); f = list_entry(pos, struct frame, head); + spin_unlock_irq(&iocq[id].lock); ktiocomplete(f); - spin_lock_irq(&iocq.lock); + + /* Figure out if extra threads are required. */ + actual_id = f->t->d->aoeminor % ncpus; + + if (!kts[actual_id].active) { + BUG_ON(id != 0); + mutex_lock(&ktio_spawn_lock); + if (!kts[actual_id].active + && aoe_ktstart(&kts[actual_id]) == 0) + kts[actual_id].active = 1; + mutex_unlock(&ktio_spawn_lock); + } + spin_lock_irq(&iocq[id].lock); } } @@ -1311,7 +1337,7 @@ kthread(void *vp) complete(&k->rendez); /* tell spawner we're running */ do { spin_lock_irq(k->lock); - more = k->fn(); + more = k->fn(k->id); if (!more) { add_wait_queue(k->waitq, &wait); __set_current_state(TASK_INTERRUPTIBLE); @@ -1340,7 +1366,7 @@ aoe_ktstart(struct ktstate *k) struct task_struct *task; init_completion(&k->rendez); - task = kthread_run(kthread, k, k->name); + task = kthread_run(kthread, k, "%s", k->name); if (task == NULL || IS_ERR(task)) return -ENOMEM; k->task = task; @@ -1353,13 +1379,24 @@ aoe_ktstart(struct ktstate *k) static void ktcomplete(struct frame *f, struct sk_buff *skb) { + int id; ulong flags; f->r_skb = skb; - spin_lock_irqsave(&iocq.lock, flags); - list_add_tail(&f->head, &iocq.head); - spin_unlock_irqrestore(&iocq.lock, flags); - wake_up(&ktiowq); + id = f->t->d->aoeminor % ncpus; + spin_lock_irqsave(&iocq[id].lock, flags); + if (!kts[id].active) { + spin_unlock_irqrestore(&iocq[id].lock, flags); + /* The thread with id has not been spawned yet, + * so delegate the work to the main thread and + * try spawning a new thread. + */ + id = 0; + spin_lock_irqsave(&iocq[id].lock, flags); + } + list_add_tail(&f->head, &iocq[id].head); + spin_unlock_irqrestore(&iocq[id].lock, flags); + wake_up(&ktiowq[id]); } struct sk_buff * @@ -1706,6 +1743,17 @@ aoe_failbuf(struct aoedev *d, struct buf *buf) void aoe_flush_iocq(void) { + int i; + + for (i = 0; i < ncpus; i++) { + if (kts[i].active) + aoe_flush_iocq_by_index(i); + } +} + +void +aoe_flush_iocq_by_index(int id) +{ struct frame *f; struct aoedev *d; LIST_HEAD(flist); @@ -1713,9 +1761,9 @@ aoe_flush_iocq(void) struct sk_buff *skb; ulong flags; - spin_lock_irqsave(&iocq.lock, flags); - list_splice_init(&iocq.head, &flist); - spin_unlock_irqrestore(&iocq.lock, flags); + spin_lock_irqsave(&iocq[id].lock, flags); + list_splice_init(&iocq[id].head, &flist); + spin_unlock_irqrestore(&iocq[id].lock, flags); while (!list_empty(&flist)) { pos = flist.next; list_del(pos); @@ -1738,6 +1786,8 @@ int __init aoecmd_init(void) { void *p; + int i; + int ret; /* get_zeroed_page returns page with ref count 1 */ p = (void *) get_zeroed_page(GFP_KERNEL | __GFP_REPEAT); @@ -1745,22 +1795,72 @@ aoecmd_init(void) return -ENOMEM; empty_page = virt_to_page(p); - INIT_LIST_HEAD(&iocq.head); - spin_lock_init(&iocq.lock); - init_waitqueue_head(&ktiowq); - kts.name = "aoe_ktio"; - kts.fn = ktio; - kts.waitq = &ktiowq; - kts.lock = &iocq.lock; - return aoe_ktstart(&kts); + ncpus = num_online_cpus(); + + iocq = kcalloc(ncpus, sizeof(struct iocq_ktio), GFP_KERNEL); + if (!iocq) + return -ENOMEM; + + kts = kcalloc(ncpus, sizeof(struct ktstate), GFP_KERNEL); + if (!kts) { + ret = -ENOMEM; + goto kts_fail; + } + + ktiowq = kcalloc(ncpus, sizeof(wait_queue_head_t), GFP_KERNEL); + if (!ktiowq) { + ret = -ENOMEM; + goto ktiowq_fail; + } + + mutex_init(&ktio_spawn_lock); + + for (i = 0; i < ncpus; i++) { + INIT_LIST_HEAD(&iocq[i].head); + spin_lock_init(&iocq[i].lock); + init_waitqueue_head(&ktiowq[i]); + snprintf(kts[i].name, sizeof(kts[i].name), "aoe_ktio%d", i); + kts[i].fn = ktio; + kts[i].waitq = &ktiowq[i]; + kts[i].lock = &iocq[i].lock; + kts[i].id = i; + kts[i].active = 0; + } + kts[0].active = 1; + if (aoe_ktstart(&kts[0])) { + ret = -ENOMEM; + goto ktstart_fail; + } + return 0; + +ktstart_fail: + kfree(ktiowq); +ktiowq_fail: + kfree(kts); +kts_fail: + kfree(iocq); + + return ret; } void aoecmd_exit(void) { - aoe_ktstop(&kts); + int i; + + for (i = 0; i < ncpus; i++) + if (kts[i].active) + aoe_ktstop(&kts[i]); + aoe_flush_iocq(); + /* Free up the iocq and thread speicific configuration + * allocated during startup. + */ + kfree(iocq); + kfree(kts); + kfree(ktiowq); + free_page((unsigned long) page_address(empty_page)); empty_page = NULL; } |