On Tue, Dec 20, 2022 at 05:19:12PM +0800, Yu Kuai wrote: > If we are using a mutex to protect rq_qos ops, it seems the right thing > to do do also using the mutex to protect blkcg_policy ops, and this > problem can be fixed because mutex can be held to alloc memroy with > GFP_KERNEL. What do you think? Getting rid of the atomic allocations would be awesome. FYI, I'm also in favor of everything that moves things out of queue_lock into more dedicated locks. queue_lock is such an undocument mess of untargeted things that don't realted to each other right now that splitting and removing it is becoming more and more important.
