bcachefs: Add a single slot percpu buf for btree iters
Allocating our array of btree iters is a big enough allocation that it
hits the buddy allocator, and we're seeing lots of lock contention.
Sticking a single element buffer in front of it should help.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index c141172..8ac9638 100644
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -541,6 +541,10 @@ struct journal_keys {
u64 journal_seq_base;
};
+struct btree_iter_buf {
+ struct btree_iter *iter;
+};
+
struct bch_fs {
struct closure cl;
@@ -636,6 +640,7 @@ struct bch_fs {
struct mutex btree_trans_lock;
struct list_head btree_trans_list;
mempool_t btree_iters_pool;
+ struct btree_iter_buf __percpu *btree_iters_bufs;
struct btree_key_cache btree_key_cache;
