Hello, On Fri, Apr 20, 2018 at 06:06:01PM +0800, Benlong Zhang wrote: > One problem with cgwb is how fs should treat metadata bios. > For example in xfs, the log might be partially stuck in one > group, leaving threads in other groups waiting for too long. > Please refer to the linux-xfs discussion: > "[PATCH V2] xfs: implement cgroup writeback support" > > One approach is to correctly tag bio->bi_css from within the > filesystems (for xfs log should be blkcg_root), and the other > is to skip them, but relies on REQ_META being set. > > It works with xfs on a cgwb porting implementation to 3.10.0. > But really not sure about other filesystems... Yeah, Josef (cc'd) is working on a similar approach but in a more generic way. Thanks. -- tejun
