Commit fbd152bf authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Minor bucket alloc optimization 



Check open buckets and buckets waiting for journal commit before doing
other expensive lookups.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent f65645d8

fs/bcachefs/alloc_foreground.c

+33 −22
Original line number Diff line number Diff line
@@ -200,14 +200,35 @@ static inline unsigned open_buckets_reserved(enum bch_watermark watermark) 
	}

}



static inline bool may_alloc_bucket(struct bch_fs *c,

				    struct bpos bucket,

				    struct bucket_alloc_state *s)

{

	if (bch2_bucket_is_open(c, bucket.inode, bucket.offset)) {

		s->skipped_open++;

		return false;

	}



	if (bch2_bucket_needs_journal_commit(&c->buckets_waiting_for_journal,

			c->journal.flushed_seq_ondisk, bucket.inode, bucket.offset)) {

		s->skipped_need_journal_commit++;

		return false;

	}



	if (bch2_bucket_nocow_is_locked(&c->nocow_locks, bucket)) {

		s->skipped_nocow++;

		return false;

	}



	return true;

}



static struct open_bucket *__try_alloc_bucket(struct bch_fs *c, struct bch_dev *ca,

					      u64 bucket, u8 gen,

					      enum bch_watermark watermark,

					      struct bucket_alloc_state *s,

					      struct closure *cl)

{

	struct open_bucket *ob;



	if (unlikely(is_superblock_bucket(c, ca, bucket)))

		return NULL;
@@ -216,22 +237,6 @@ static struct open_bucket *__try_alloc_bucket(struct bch_fs *c, struct bch_dev * 
		return NULL;

	}



	if (bch2_bucket_is_open(c, ca->dev_idx, bucket)) {

		s->skipped_open++;

		return NULL;

	}



	if (bch2_bucket_needs_journal_commit(&c->buckets_waiting_for_journal,

			c->journal.flushed_seq_ondisk, ca->dev_idx, bucket)) {

		s->skipped_need_journal_commit++;

		return NULL;

	}



	if (bch2_bucket_nocow_is_locked(&c->nocow_locks, POS(ca->dev_idx, bucket))) {

		s->skipped_nocow++;

		return NULL;

	}



	spin_lock(&c->freelist_lock);



	if (unlikely(c->open_buckets_nr_free <= open_buckets_reserved(watermark))) {
@@ -250,10 +255,9 @@ static struct open_bucket *__try_alloc_bucket(struct bch_fs *c, struct bch_dev * 
		return NULL;

	}



	ob = bch2_open_bucket_alloc(c);

	struct open_bucket *ob = bch2_open_bucket_alloc(c);



	spin_lock(&ob->lock);



	ob->valid	= true;

	ob->sectors_free = ca->mi.bucket_size;

	ob->dev		= ca->dev_idx;
@@ -279,8 +283,11 @@ static struct open_bucket *try_alloc_bucket(struct btree_trans *trans, struct bc 
{

	struct bch_fs *c = trans->c;

	u64 b = freespace_iter->pos.offset & ~(~0ULL << 56);

	u8 gen;



	if (!may_alloc_bucket(c, POS(ca->dev_idx, b), s))

		return NULL;



	u8 gen;

	int ret = bch2_check_discard_freespace_key(trans, freespace_iter, &gen, true);

	if (ret < 0)

		return ERR_PTR(ret);
@@ -300,6 +307,7 @@ bch2_bucket_alloc_early(struct btree_trans *trans, 
			struct bucket_alloc_state *s,

			struct closure *cl)

{

	struct bch_fs *c = trans->c;

	struct btree_iter iter, citer;

	struct bkey_s_c k, ck;

	struct open_bucket *ob = NULL;
@@ -359,7 +367,10 @@ bch2_bucket_alloc_early(struct btree_trans *trans, 


		s->buckets_seen++;



		ob = __try_alloc_bucket(trans->c, ca, k.k->p.offset, a->gen, watermark, s, cl);

		ob = may_alloc_bucket(c, k.k->p, s)

			? __try_alloc_bucket(c, ca, k.k->p.offset, a->gen,

					     watermark, s, cl)

			: NULL;

next:

		bch2_set_btree_iter_dontneed(&citer);

		bch2_trans_iter_exit(trans, &citer);