Hello, On Wed, Jul 28, 2021 at 10:33:20AM +0800, brookxu wrote: > If we do this, I think we will encounter some problems, as follows: > 1. blk-throttle is now at the top of the IO stack. Changing the position of the throttle hook > will make this mechanism invalid for some devices. > 2. We may also need to add a new hook to handle back-merge, otherwise I think the isolation > effect will be worse in the sequential IO scene. > 3. Since bio has entered the IO stack, if it is suspended and resubmitted by blk-throttle, > then there is an IO stack reentry problem, which I think may cause many small problems. Yeah, you're right. I don't think it's worth rocking the boat with blk-throtl at this point. An extra callback it is then. Thanks. -- tejun