btrfs: account ticket size at add/delete time
Instead of iterating all pending tickets on the normal/priority list to
sum their total size the cost can be amortized across ticket addition/
removal. This turns O(n) + O(m) (where n is the size of the normal list
and m of the priority list) into O(1). This will mostly have effect in
workloads that experience heavy flushing.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h
index 24514cd..0a5001e 100644
--- a/fs/btrfs/space-info.h
+++ b/fs/btrfs/space-info.h
@@ -54,6 +54,13 @@ struct btrfs_space_info {
struct list_head ro_bgs;
struct list_head priority_tickets;
struct list_head tickets;
+
+ /*
+ * Size of space that needs to be reclaimed in order to satisfy pending
+ * tickets
+ */
+ u64 reclaim_size;
+
/*
* tickets_id just indicates the next ticket will be handled, so note
* it's not stored per ticket.
