What is single or multi thread concept in area of file system?

Question

As known, the gingerbread is going to adopt ext4 to replace the YAFFS. The reason seems to be that YAFFS is single-threaded. Will someone explain what does "single-threaded" mean in the area of file system? So ext4 is multi-threaded? From what aspect?

thanks.

Answer 1

Merlyn's comment was the right one. Per that document:

YAFFS is locked on a per-partition basis at a high level. This is simpler than tracking lower-level locking. Yaffs Direct Interface uses a single lock for all partitions.

IOW, only one thread can write to the whole partition at once.

Most Linux filesystems, like ext4, allow multiple threads to write at once (though file-level locks may serialize access to individual files).