Hi Bart! > My understanding is that ionice uses the ioprio_set() system call and > hence only affects foreground I/O but not page cache writeback. This > is why I introduced the ioprio rq-qos policy (block/blk-ioprio.c). How > about not adding CDL support in ioprio_set() and only supporting > configuration of CDL via the v2 cgroup mechanism? I suspect applications that care about CDL would probably not go through the page cache. But I don't have a problem supporting cgroups at all. Longer term, for the applications that I'm aware of that care about this, we'd probably want to be able to specify things on a per-I/O basis via io_uring, though. -- Martin K. Petersen Oracle Linux Engineering
