From 119ba0f82839cd80eaef3e6991988f1403965d5b Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Wed, 24 Apr 2013 19:01:12 -0700 Subject: bcache: Convert allocator thread to kthread Using a workqueue when we just want a single thread is a bit silly. Signed-off-by: Kent Overstreet --- drivers/md/bcache/alloc.c | 34 ++++++++++++++++++++++------------ drivers/md/bcache/bcache.h | 17 +++++++++++------ drivers/md/bcache/btree.c | 6 +++--- drivers/md/bcache/super.c | 19 +++++++------------ 4 files changed, 43 insertions(+), 33 deletions(-) diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c index 048f2947e08b..38428f46ea74 100644 --- a/drivers/md/bcache/alloc.c +++ b/drivers/md/bcache/alloc.c @@ -63,6 +63,7 @@ #include "bcache.h" #include "btree.h" +#include #include #define MAX_IN_FLIGHT_DISCARDS 8U @@ -151,7 +152,7 @@ static void discard_finish(struct work_struct *w) mutex_unlock(&ca->set->bucket_lock); closure_wake_up(&ca->set->bucket_wait); - wake_up(&ca->set->alloc_wait); + wake_up_process(ca->alloc_thread); closure_put(&ca->set->cl); } @@ -358,30 +359,26 @@ static void invalidate_buckets(struct cache *ca) #define allocator_wait(ca, cond) \ do { \ - DEFINE_WAIT(__wait); \ - \ while (1) { \ - prepare_to_wait(&ca->set->alloc_wait, \ - &__wait, TASK_INTERRUPTIBLE); \ + set_current_state(TASK_INTERRUPTIBLE); \ if (cond) \ break; \ \ mutex_unlock(&(ca)->set->bucket_lock); \ if (test_bit(CACHE_SET_STOPPING_2, &ca->set->flags)) { \ - finish_wait(&ca->set->alloc_wait, &__wait); \ - closure_return(cl); \ + closure_put(&ca->set->cl); \ + return 0; \ } \ \ schedule(); \ mutex_lock(&(ca)->set->bucket_lock); \ } \ - \ - finish_wait(&ca->set->alloc_wait, &__wait); \ + __set_current_state(TASK_RUNNING); \ } while (0) -void bch_allocator_thread(struct closure *cl) +static int bch_allocator_thread(void *arg) { - struct cache *ca = container_of(cl, struct cache, alloc); + struct cache *ca = arg; mutex_lock(&ca->set->bucket_lock); @@ -442,7 +439,7 @@ long bch_bucket_alloc(struct cache *ca, unsigned watermark, struct closure *cl) { long r = -1; again: - wake_up(&ca->set->alloc_wait); + wake_up_process(ca->alloc_thread); if (fifo_used(&ca->free) > ca->watermark[watermark] && fifo_pop(&ca->free, r)) { @@ -552,6 +549,19 @@ int bch_bucket_alloc_set(struct cache_set *c, unsigned watermark, /* Init */ +int bch_cache_allocator_start(struct cache *ca) +{ + ca->alloc_thread = kthread_create(bch_allocator_thread, + ca, "bcache_allocator"); + if (IS_ERR(ca->alloc_thread)) + return PTR_ERR(ca->alloc_thread); + + closure_get(&ca->set->cl); + wake_up_process(ca->alloc_thread); + + return 0; +} + void bch_cache_allocator_exit(struct cache *ca) { struct discard *d; diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index d3e15b42a4ab..166c8ddc0be4 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -565,8 +565,7 @@ struct cache { unsigned watermark[WATERMARK_MAX]; - struct closure alloc; - struct workqueue_struct *alloc_workqueue; + struct task_struct *alloc_thread; struct closure prio; struct prio_set *disk_buckets; @@ -703,9 +702,6 @@ struct cache_set { /* For the btree cache */ struct shrinker shrink; - /* For the allocator itself */ - wait_queue_head_t alloc_wait; - /* For the btree cache and anything allocation related */ struct mutex bucket_lock; @@ -1173,6 +1169,15 @@ static inline uint8_t bucket_disk_gen(struct bucket *b) static struct kobj_attribute ksysfs_##n = \ __ATTR(n, S_IWUSR|S_IRUSR, show, store) +static inline void wake_up_allocators(struct cache_set *c) +{ + struct cache *ca; + unsigned i; + + for_each_cache(ca, c, i) + wake_up_process(ca->alloc_thread); +} + /* Forward declarations */ void bch_writeback_queue(struct cached_dev *); @@ -1193,7 +1198,6 @@ void bch_submit_bbio(struct bio *, struct cache_set *, struct bkey *, unsigned); uint8_t bch_inc_gen(struct cache *, struct bucket *); void bch_rescale_priorities(struct cache_set *, int); bool bch_bucket_add_unused(struct cache *, struct bucket *); -void bch_allocator_thread(struct closure *); long bch_bucket_alloc(struct cache *, unsigned, struct closure *); void bch_bucket_free(struct cache_set *, struct bkey *); @@ -1244,6 +1248,7 @@ int bch_btree_cache_alloc(struct cache_set *); void bch_cached_dev_writeback_init(struct cached_dev *); void bch_moving_init_cache_set(struct cache_set *); +int bch_cache_allocator_start(struct cache *ca); void bch_cache_allocator_exit(struct cache *ca); int bch_cache_allocator_init(struct cache *ca); diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 7a5658f04e62..45b88fbffbe0 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -273,7 +273,7 @@ static void btree_complete_write(struct btree *b, struct btree_write *w) { if (w->prio_blocked && !atomic_sub_return(w->prio_blocked, &b->c->prio_blocked)) - wake_up(&b->c->alloc_wait); + wake_up_allocators(b->c); if (w->journal) { atomic_dec_bug(w->journal); @@ -984,7 +984,7 @@ static void btree_node_free(struct btree *b, struct btree_op *op) if (b->prio_blocked && !atomic_sub_return(b->prio_blocked, &b->c->prio_blocked)) - wake_up(&b->c->alloc_wait); + wake_up_allocators(b->c); b->prio_blocked = 0; @@ -1547,7 +1547,7 @@ static void bch_btree_gc(struct closure *cl) blktrace_msg_all(c, "Finished gc"); trace_bcache_gc_end(c->sb.set_uuid); - wake_up(&c->alloc_wait); + wake_up_allocators(c); continue_at(cl, bch_moving_gc, bch_gc_wq); } diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 3de5626919ef..aaeda235fc75 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1282,7 +1282,7 @@ static void cache_set_flush(struct closure *cl) /* Shut down allocator threads */ set_bit(CACHE_SET_STOPPING_2, &c->flags); - wake_up(&c->alloc_wait); + wake_up_allocators(c); bch_cache_accounting_destroy(&c->accounting); @@ -1373,7 +1373,6 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb) c->btree_pages = max_t(int, c->btree_pages / 4, BTREE_MAX_PAGES); - init_waitqueue_head(&c->alloc_wait); mutex_init(&c->bucket_lock); mutex_init(&c->fill_lock); mutex_init(&c->sort_lock); @@ -1496,9 +1495,10 @@ static void run_cache_set(struct cache_set *c) */ bch_journal_next(&c->journal); + err = "error starting allocator thread"; for_each_cache(ca, c, i) - closure_call(&ca->alloc, bch_allocator_thread, - system_wq, &c->cl); + if (bch_cache_allocator_start(ca)) + goto err; /* * First place it's safe to allocate: btree_check() and @@ -1531,17 +1531,16 @@ static void run_cache_set(struct cache_set *c) bch_btree_gc_finish(c); + err = "error starting allocator thread"; for_each_cache(ca, c, i) - closure_call(&ca->alloc, bch_allocator_thread, - ca->alloc_workqueue, &c->cl); + if (bch_cache_allocator_start(ca)) + goto err; mutex_lock(&c->bucket_lock); for_each_cache(ca, c, i) bch_prio_write(ca); mutex_unlock(&c->bucket_lock); - wake_up(&c->alloc_wait); - err = "cannot allocate new UUID bucket"; if (__uuid_write(c)) goto err_unlock_gc; @@ -1673,9 +1672,6 @@ void bch_cache_release(struct kobject *kobj) bio_split_pool_free(&ca->bio_split_hook); - if (ca->alloc_workqueue) - destroy_workqueue(ca->alloc_workqueue); - free_pages((unsigned long) ca->disk_buckets, ilog2(bucket_pages(ca))); kfree(ca->prio_buckets); vfree(ca->buckets); @@ -1723,7 +1719,6 @@ static int cache_alloc(struct cache_sb *sb, struct cache *ca) !(ca->prio_buckets = kzalloc(sizeof(uint64_t) * prio_buckets(ca) * 2, GFP_KERNEL)) || !(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca)) || - !(ca->alloc_workqueue = alloc_workqueue("bch_allocator", 0, 1)) || bio_split_pool_init(&ca->bio_split_hook)) return -ENOMEM; -- cgit v1.2.3