Re: [PATCH] backing dev unplugging

Andrew Morton
2004-03-10T21:00:33Z

Jens Axboe <axboe@suse.de> wrote:
>
> Here's a first cut at killing global plugging of block devices to reduce
> the nasty contention blk_plug_lock caused.

Shouldn't we take read_lock(&md->map_lock) in dm_table_unplug_all()?

If so, what are the lock ranking issues here? The queue lock is not held
yet, so it seems pretty simple?