diff options
| -rw-r--r-- | fs/btrfs/async-thread.c | 81 | ||||
| -rw-r--r-- | fs/btrfs/async-thread.h | 10 | ||||
| -rw-r--r-- | fs/btrfs/ctree.h | 1 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.c | 42 | ||||
| -rw-r--r-- | fs/btrfs/relocation.c | 4 |
5 files changed, 106 insertions, 32 deletions
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c index 282ca08..c0861e7 100644 --- a/fs/btrfs/async-thread.c +++ b/fs/btrfs/async-thread.c @@ -64,6 +64,51 @@ struct btrfs_worker_thread { }; /* + * btrfs_start_workers uses kthread_run, which can block waiting for memory + * for a very long time. It will actually throttle on page writeback, + * and so it may not make progress until after our btrfs worker threads + * process all of the pending work structs in their queue + * + * This means we can't use btrfs_start_workers from inside a btrfs worker + * thread that is used as part of cleaning dirty memory, which pretty much + * involves all of the worker threads. + * + * Instead we have a helper queue who never has more than one thread + * where we scheduler thread start operations. This worker_start struct + * is used to contain the work and hold a pointer to the queue that needs + * another worker. + */ +struct worker_start { + struct btrfs_work work; + struct btrfs_workers *queue; +}; + +static void start_new_worker_func(struct btrfs_work *work) +{ + struct worker_start *start; + start = container_of(work, struct worker_start, work); + btrfs_start_workers(start->queue, 1); + kfree(start); +} + +static int start_new_worker(struct btrfs_workers *queue) +{ + struct worker_start *start; + int ret; + + start = kzalloc(sizeof(*start), GFP_NOFS); + if (!start) + return -ENOMEM; + + start->work.func = start_new_worker_func; + start->queue = queue; + ret = btrfs_queue_worker(queue->atomic_worker_start, &start->work); + if (ret) + kfree(start); + return ret; +} + +/* * helper function to move a thread onto the idle list after it * has finished some requests. */ @@ -118,11 +163,13 @@ static void check_pending_worker_creates(struct btrfs_worker_thread *worker) goto out; workers->atomic_start_pending = 0; - if (workers->num_workers >= workers->max_workers) + if (workers->num_workers + workers->num_workers_starting >= + workers->max_workers) goto out; + workers->num_workers_starting += 1; spin_unlock_irqrestore(&workers->lock, flags); - btrfs_start_workers(workers, 1); + start_new_worker(workers); return; out: @@ -390,9 +437,11 @@ int btrfs_stop_workers(struct btrfs_workers *workers) /* * simple init on struct btrfs_workers */ -void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max) +void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max, + struct btrfs_workers *async_helper) { workers->num_workers = 0; + workers->num_workers_starting = 0; INIT_LIST_HEAD(&workers->worker_list); INIT_LIST_HEAD(&workers->idle_list); INIT_LIST_HEAD(&workers->order_list); @@ -404,14 +453,15 @@ void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max) workers->name = name; workers->ordered = 0; workers->atomic_start_pending = 0; - workers->atomic_worker_start = 0; + workers->atomic_worker_start = async_helper; } /* * starts new worker threads. This does not enforce the max worker * count in case you need to temporarily go past it. */ -int btrfs_start_workers(struct btrfs_workers *workers, int num_workers) +static int __btrfs_start_workers(struct btrfs_workers *workers, + int num_workers) { struct btrfs_worker_thread *worker; int ret = 0; @@ -444,6 +494,8 @@ int btrfs_start_workers(struct btrfs_workers *workers, int num_workers) list_add_tail(&worker->worker_list, &workers->idle_list); worker->idle = 1; workers->num_workers++; + workers->num_workers_starting--; + WARN_ON(workers->num_workers_starting < 0); spin_unlock_irq(&workers->lock); } return 0; @@ -452,6 +504,14 @@ fail: return ret; } +int btrfs_start_workers(struct btrfs_workers *workers, int num_workers) +{ + spin_lock_irq(&workers->lock); + workers->num_workers_starting += num_workers; + spin_unlock_irq(&workers->lock); + return __btrfs_start_workers(workers, num_workers); +} + /* * run through the list and find a worker thread that doesn't have a lot * to do right now. This can return null if we aren't yet at the thread @@ -461,7 +521,10 @@ static struct btrfs_worker_thread *next_worker(struct btrfs_workers *workers) { struct btrfs_worker_thread *worker; struct list_head *next; - int enforce_min = workers->num_workers < workers->max_workers; + int enforce_min; + + enforce_min = (workers->num_workers + workers->num_workers_starting) < + workers->max_workers; /* * if we find an idle thread, don't move it to the end of the @@ -509,15 +572,17 @@ again: worker = next_worker(workers); if (!worker) { - if (workers->num_workers >= workers->max_workers) { + if (workers->num_workers + workers->num_workers_starting >= + workers->max_workers) { goto fallback; } else if (workers->atomic_worker_start) { workers->atomic_start_pending = 1; goto fallback; } else { + workers->num_workers_starting++; spin_unlock_irqrestore(&workers->lock, flags); /* we're below the limit, start another worker */ - btrfs_start_workers(workers, 1); + __btrfs_start_workers(workers, 1); goto again; } } diff --git a/fs/btrfs/async-thread.h b/fs/btrfs/async-thread.h index fc089b9..5077746 100644 --- a/fs/btrfs/async-thread.h +++ b/fs/btrfs/async-thread.h @@ -64,6 +64,8 @@ struct btrfs_workers { /* current number of running workers */ int num_workers; + int num_workers_starting; + /* max number of workers allowed. changed by btrfs_start_workers */ int max_workers; @@ -78,9 +80,10 @@ struct btrfs_workers { /* * are we allowed to sleep while starting workers or are we required - * to start them at a later time? + * to start them at a later time? If we can't sleep, this indicates + * which queue we need to use to schedule thread creation. */ - int atomic_worker_start; + struct btrfs_workers *atomic_worker_start; /* list with all the work threads. The workers on the idle thread * may be actively servicing jobs, but they haven't yet hit the @@ -109,7 +112,8 @@ struct btrfs_workers { int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work); int btrfs_start_workers(struct btrfs_workers *workers, int num_workers); int btrfs_stop_workers(struct btrfs_workers *workers); -void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max); +void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max, + struct btrfs_workers *async_starter); int btrfs_requeue_work(struct btrfs_work *work); void btrfs_set_work_high_prio(struct btrfs_work *work); #endif diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 8184f2f..1b920ff 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -907,6 +907,7 @@ struct btrfs_fs_info { * A third pool does submit_bio to avoid deadlocking with the other * two */ + struct btrfs_workers generic_worker; struct btrfs_workers workers; struct btrfs_workers delalloc_workers; struct btrfs_workers endio_workers; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 69dce50..9903f04 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1746,21 +1746,22 @@ struct btrfs_root *open_ctree(struct super_block *sb, err = -EINVAL; goto fail_iput; } -printk("thread pool is %d\n", fs_info->thread_pool_size); - /* - * we need to start all the end_io workers up front because the - * queue work function gets called at interrupt time, and so it - * cannot dynamically grow. - */ + + btrfs_init_workers(&fs_info->generic_worker, + "genwork", 1, NULL); + btrfs_init_workers(&fs_info->workers, "worker", - fs_info->thread_pool_size); + fs_info->thread_pool_size, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->delalloc_workers, "delalloc", - fs_info->thread_pool_size); + fs_info->thread_pool_size, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->submit_workers, "submit", min_t(u64, fs_devices->num_devices, - fs_info->thread_pool_size)); + fs_info->thread_pool_size), + &fs_info->generic_worker); /* a higher idle thresh on the submit workers makes it much more * likely that bios will be send down in a sane order to the @@ -1774,15 +1775,20 @@ printk("thread pool is %d\n", fs_info->thread_pool_size); fs_info->delalloc_workers.idle_thresh = 2; fs_info->delalloc_workers.ordered = 1; - btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1); + btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->endio_workers, "endio", - fs_info->thread_pool_size); + fs_info->thread_pool_size, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta", - fs_info->thread_pool_size); + fs_info->thread_pool_size, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->endio_meta_write_workers, - "endio-meta-write", fs_info->thread_pool_size); + "endio-meta-write", fs_info->thread_pool_size, + &fs_info->generic_worker); btrfs_init_workers(&fs_info->endio_write_workers, "endio-write", - fs_info->thread_pool_size); + fs_info->thread_pool_size, + &fs_info->generic_worker); /* * endios are largely parallel and should have a very @@ -1794,12 +1800,8 @@ printk("thread pool is %d\n", fs_info->thread_pool_size); fs_info->endio_write_workers.idle_thresh = 2; fs_info->endio_meta_write_workers.idle_thresh = 2; - fs_info->endio_workers.atomic_worker_start = 1; - fs_info->endio_meta_workers.atomic_worker_start = 1; - fs_info->endio_write_workers.atomic_worker_start = 1; - fs_info->endio_meta_write_workers.atomic_worker_start = 1; - btrfs_start_workers(&fs_info->workers, 1); + btrfs_start_workers(&fs_info->generic_worker, 1); btrfs_start_workers(&fs_info->submit_workers, 1); btrfs_start_workers(&fs_info->delalloc_workers, 1); btrfs_start_workers(&fs_info->fixup_workers, 1); @@ -2012,6 +2014,7 @@ fail_chunk_root: free_extent_buffer(chunk_root->node); free_extent_buffer(chunk_root->commit_root); fail_sb_buffer: + btrfs_stop_workers(&fs_info->generic_worker); btrfs_stop_workers(&fs_info->fixup_workers); btrfs_stop_workers(&fs_info->delalloc_workers); btrfs_stop_workers(&fs_info->workers); @@ -2437,6 +2440,7 @@ int close_ctree(struct btrfs_root *root) iput(fs_info->btree_inode); + btrfs_stop_workers(&fs_info->generic_worker); btrfs_stop_workers(&fs_info->fixup_workers); btrfs_stop_workers(&fs_info->delalloc_workers); btrfs_stop_workers(&fs_info->workers); diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 361ad32..cfcc93c 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -3518,7 +3518,7 @@ int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start) BUG_ON(!rc->block_group); btrfs_init_workers(&rc->workers, "relocate", - fs_info->thread_pool_size); + fs_info->thread_pool_size, NULL); rc->extent_root = extent_root; btrfs_prepare_block_group_relocation(extent_root, rc->block_group); @@ -3701,7 +3701,7 @@ int btrfs_recover_relocation(struct btrfs_root *root) mapping_tree_init(&rc->reloc_root_tree); INIT_LIST_HEAD(&rc->reloc_roots); btrfs_init_workers(&rc->workers, "relocate", - root->fs_info->thread_pool_size); + root->fs_info->thread_pool_size, NULL); rc->extent_root = root->fs_info->extent_root; set_reloc_control(rc); |