Commit 7857d5d4 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcache: Fix a journalling performance bug

parent 1fa8455d

drivers/md/bcache/journal.c

+26 −21
Original line number Diff line number Diff line
@@ -554,32 +554,26 @@ static void journal_write_endio(struct bio *bio, int error) 
	struct journal_write *w = bio->bi_private;



	cache_set_err_on(error, w->c, "journal io error");

	closure_put(&w->c->journal.io.cl);

	closure_put(&w->c->journal.io);

}



static void journal_write(struct closure *);



static void journal_write_done(struct closure *cl)

{

	struct journal *j = container_of(cl, struct journal, io.cl);

	struct cache_set *c = container_of(j, struct cache_set, journal);



	struct journal *j = container_of(cl, struct journal, io);

	struct journal_write *w = (j->cur == j->w)

		? &j->w[1]

		: &j->w[0];



	__closure_wake_up(&w->wait);



	if (c->journal_delay_ms)

		closure_delay(&j->io, msecs_to_jiffies(c->journal_delay_ms));



	continue_at(cl, journal_write, system_wq);

	continue_at_nobarrier(cl, journal_write, system_wq);

}



static void journal_write_unlocked(struct closure *cl)

	__releases(c->journal.lock)

{

	struct cache_set *c = container_of(cl, struct cache_set, journal.io.cl);

	struct cache_set *c = container_of(cl, struct cache_set, journal.io);

	struct cache *ca;

	struct journal_write *w = c->journal.cur;

	struct bkey *k = &c->journal.key;
@@ -660,7 +654,7 @@ static void journal_write_unlocked(struct closure *cl) 


static void journal_write(struct closure *cl)

{

	struct cache_set *c = container_of(cl, struct cache_set, journal.io.cl);

	struct cache_set *c = container_of(cl, struct cache_set, journal.io);



	spin_lock(&c->journal.lock);

	journal_write_unlocked(cl);
@@ -669,7 +663,10 @@ static void journal_write(struct closure *cl) 
static void __journal_try_write(struct cache_set *c, bool noflush)

	__releases(c->journal.lock)

{

	struct closure *cl = &c->journal.io.cl;

	struct closure *cl = &c->journal.io;

	struct journal_write *w = c->journal.cur;



	w->need_write = true;



	if (!closure_trylock(cl, &c->cl))

		spin_unlock(&c->journal.lock);
@@ -688,18 +685,24 @@ void bch_journal_meta(struct cache_set *c, struct closure *cl) 


	if (CACHE_SYNC(&c->sb)) {

		spin_lock(&c->journal.lock);



		w = c->journal.cur;

		w->need_write = true;



		if (cl)

			BUG_ON(!closure_wait(&w->wait, cl));



		closure_flush(&c->journal.io);

		__journal_try_write(c, true);

	}

}



static void journal_write_work(struct work_struct *work)

{

	struct cache_set *c = container_of(to_delayed_work(work),

					   struct cache_set,

					   journal.work);

	spin_lock(&c->journal.lock);

	journal_try_write(c);

}



/*

 * Entry point to the journalling code - bio_insert() and btree_invalidate()

 * pass bch_journal() a list of keys to be journalled, and then
@@ -739,7 +742,6 @@ void bch_journal(struct closure *cl) 
	}



	w = c->journal.cur;

	w->need_write = true;

	b = __set_blocks(w->data, w->data->keys + n, c);



	if (b * c->sb.block_size > PAGE_SECTORS << JSET_BITS ||
@@ -755,8 +757,6 @@ void bch_journal(struct closure *cl) 


		BUG_ON(!closure_wait(&w->wait, cl));



		closure_flush(&c->journal.io);



		journal_try_write(c);

		continue_at(cl, bch_journal, bcache_wq);

	}
@@ -768,11 +768,15 @@ void bch_journal(struct closure *cl) 
	atomic_inc(op->journal);



	if (op->flush_journal) {

		closure_flush(&c->journal.io);

		closure_wait(&w->wait, cl->parent);

	}



		journal_try_write(c);

	} else if (!w->need_write) {

		schedule_delayed_work(&c->journal.work,

				      msecs_to_jiffies(c->journal_delay_ms));

		spin_unlock(&c->journal.lock);

	} else {

		spin_unlock(&c->journal.lock);

	}

out:

	bch_btree_insert_async(cl);

}
@@ -790,6 +794,7 @@ int bch_journal_alloc(struct cache_set *c) 


	closure_init_unlocked(&j->io);

	spin_lock_init(&j->lock);

	INIT_DELAYED_WORK(&j->work, journal_write_work);



	c->journal_delay_ms = 100;

drivers/md/bcache/journal.h

+2 −1
Original line number Diff line number Diff line
@@ -140,7 +140,8 @@ struct journal { 
	spinlock_t		lock;

	/* used when waiting because the journal was full */

	struct closure_waitlist	wait;

	struct closure_with_timer io;

	struct closure		io;

	struct delayed_work	work;



	/* Number of blocks free in the bucket(s) we're currently writing to */

	unsigned		blocks_free;