Hello, On Tue, Jul 27, 2021 at 11:06:18AM +0800, brookxu wrote: > Make blk-throttle use rq-qos may be more elegant. But I found that there may be at least > one problem that is difficult to solve. blk-throttle supports separate throttle for read > and write IOs, which means that we cannot suspend tasks during throttle, but rq-qos > throttle IOs by suspending tasks. Ah, right, I forgot about that. > We may be able to relocate the blk-throttle hooks to the rq-qos hooks. Since we may not > be able to replace the throttle hook, in this case, if we register a rq-qos to the system, > part of the blk-throttle hooks is in rq-qos and part hooks not, which feels a bit confusing. > In addition, we may need to implement more hooks, such as IO merge hook. Would it be possible to just move the blk-throtl throttling hook right next to the rq-qos hook so that it gets throttled after splitting? Thanks. -- tejun