diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-core.c | 37 | ||||
| -rw-r--r-- | block/blktrace.c | 23 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 36 | ||||
| -rw-r--r-- | block/elevator.c | 2 |
4 files changed, 72 insertions, 26 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 6a9cc0d22a6..1905aaba49f 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -806,35 +806,32 @@ static struct request *get_request_wait(struct request_queue *q, int rw_flags, rq = get_request(q, rw_flags, bio, GFP_NOIO); while (!rq) { DEFINE_WAIT(wait); + struct io_context *ioc; struct request_list *rl = &q->rq; prepare_to_wait_exclusive(&rl->wait[rw], &wait, TASK_UNINTERRUPTIBLE); - rq = get_request(q, rw_flags, bio, GFP_NOIO); - - if (!rq) { - struct io_context *ioc; + blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ); - blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ); - - __generic_unplug_device(q); - spin_unlock_irq(q->queue_lock); - io_schedule(); + __generic_unplug_device(q); + spin_unlock_irq(q->queue_lock); + io_schedule(); - /* - * After sleeping, we become a "batching" process and - * will be able to allocate at least one request, and - * up to a big batch of them for a small period time. - * See ioc_batching, ioc_set_batching - */ - ioc = current_io_context(GFP_NOIO, q->node); - ioc_set_batching(q, ioc); + /* + * After sleeping, we become a "batching" process and + * will be able to allocate at least one request, and + * up to a big batch of them for a small period time. + * See ioc_batching, ioc_set_batching + */ + ioc = current_io_context(GFP_NOIO, q->node); + ioc_set_batching(q, ioc); - spin_lock_irq(q->queue_lock); - } + spin_lock_irq(q->queue_lock); finish_wait(&rl->wait[rw], &wait); - } + + rq = get_request(q, rw_flags, bio, GFP_NOIO); + }; return rq; } diff --git a/block/blktrace.c b/block/blktrace.c index b2cbb4e5d76..7ae87cc4a16 100644 --- a/block/blktrace.c +++ b/block/blktrace.c @@ -75,6 +75,23 @@ static void trace_note_time(struct blk_trace *bt) local_irq_restore(flags); } +void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) +{ + int n; + va_list args; + char *buf; + + preempt_disable(); + buf = per_cpu_ptr(bt->msg_data, smp_processor_id()); + va_start(args, fmt); + n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args); + va_end(args); + + trace_note(bt, 0, BLK_TN_MESSAGE, buf, n); + preempt_enable(); +} +EXPORT_SYMBOL_GPL(__trace_note_message); + static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector, pid_t pid) { @@ -232,6 +249,7 @@ static void blk_trace_cleanup(struct blk_trace *bt) debugfs_remove(bt->dropped_file); blk_remove_tree(bt->dir); free_percpu(bt->sequence); + free_percpu(bt->msg_data); kfree(bt); } @@ -346,6 +364,10 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, if (!bt->sequence) goto err; + bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG); + if (!bt->msg_data) + goto err; + ret = -ENOENT; dir = blk_create_tree(buts->name); if (!dir) @@ -392,6 +414,7 @@ err: if (bt->dropped_file) debugfs_remove(bt->dropped_file); free_percpu(bt->sequence); + free_percpu(bt->msg_data); if (bt->rchan) relay_close(bt->rchan); kfree(bt); diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index b399c62936e..d01b411c72f 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -124,6 +124,8 @@ struct cfq_data { struct cfq_queue { /* reference count */ atomic_t ref; + /* various state flags, see below */ + unsigned int flags; /* parent cfq_data */ struct cfq_data *cfqd; /* service_tree member */ @@ -138,14 +140,14 @@ struct cfq_queue { int queued[2]; /* currently allocated requests */ int allocated[2]; - /* pending metadata requests */ - int meta_pending; /* fifo list of requests in sort_list */ struct list_head fifo; unsigned long slice_end; long slice_resid; + /* pending metadata requests */ + int meta_pending; /* number of requests that are on the dispatch list or inside driver */ int dispatched; @@ -153,8 +155,6 @@ struct cfq_queue { unsigned short ioprio, org_ioprio; unsigned short ioprio_class, org_ioprio_class; - /* various state flags, see below */ - unsigned int flags; }; enum cfqq_state_flags { @@ -1142,6 +1142,9 @@ static void cfq_put_queue(struct cfq_queue *cfqq) kmem_cache_free(cfq_pool, cfqq); } +/* + * Must always be called with the rcu_read_lock() held + */ static void __call_for_each_cic(struct io_context *ioc, void (*func)(struct io_context *, struct cfq_io_context *)) @@ -1197,6 +1200,11 @@ static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic) cfq_cic_free(cic); } +/* + * Must be called with rcu_read_lock() held or preemption otherwise disabled. + * Only two callers of this - ->dtor() which is called with the rcu_read_lock(), + * and ->trim() which is called with the task lock held + */ static void cfq_free_io_context(struct io_context *ioc) { /* @@ -1502,20 +1510,24 @@ static struct cfq_io_context * cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) { struct cfq_io_context *cic; + unsigned long flags; void *k; if (unlikely(!ioc)) return NULL; + rcu_read_lock(); + /* * we maintain a last-hit cache, to avoid browsing over the tree */ cic = rcu_dereference(ioc->ioc_data); - if (cic && cic->key == cfqd) + if (cic && cic->key == cfqd) { + rcu_read_unlock(); return cic; + } do { - rcu_read_lock(); cic = radix_tree_lookup(&ioc->radix_root, (unsigned long) cfqd); rcu_read_unlock(); if (!cic) @@ -1524,10 +1536,13 @@ cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) k = cic->key; if (unlikely(!k)) { cfq_drop_dead_cic(cfqd, ioc, cic); + rcu_read_lock(); continue; } + spin_lock_irqsave(&ioc->lock, flags); rcu_assign_pointer(ioc->ioc_data, cic); + spin_unlock_irqrestore(&ioc->lock, flags); break; } while (1); @@ -2134,6 +2149,10 @@ static void *cfq_init_queue(struct request_queue *q) static void cfq_slab_kill(void) { + /* + * Caller already ensured that pending RCU callbacks are completed, + * so we should have no busy allocations at this point. + */ if (cfq_pool) kmem_cache_destroy(cfq_pool); if (cfq_ioc_pool) @@ -2292,6 +2311,11 @@ static void __exit cfq_exit(void) ioc_gone = &all_gone; /* ioc_gone's update must be visible before reading ioc_count */ smp_wmb(); + + /* + * this also protects us from entering cfq_slab_kill() with + * pending RCU callbacks + */ if (elv_ioc_count_read(ioc_count)) wait_for_completion(ioc_gone); cfq_slab_kill(); diff --git a/block/elevator.c b/block/elevator.c index 980f8ae147b..902dd1344d5 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -1110,6 +1110,8 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q); spin_unlock_irq(q->queue_lock); + blk_add_trace_msg(q, "elv switch: %s", e->elevator_type->elevator_name); + return 1; fail_register: |