On Mon, Jan 10, 2022 at 05:10:46PM +0800, Wang Jianchao wrote: > From: Wang Jianchao <wangjianchao@xxxxxxxxxxxx> > > iostat can only track the whole device's io statistics. This patch > introduces iostat per cgroup based on blk-rq-qos framework which > can track bw, iops, queue latency and device latency and distinguish > regular or meta data. The blkio.iostat per cgroup output in following > format, > vda-data bytes iops queue_lat dev_lat [ditto] [ditto] > meta \___________ ______________/ | | > v v v > read write discard > In particular, the blkio.iostat of root only output the statistics > of IOs from root cgroup. However, the non-root blkio.iostat outputs > all of the children cgroups. With meta stats in root cgroup, hope > to observe the performace of fs metadata. I think using bpf is a way better solution for this kind of detailed statistics. What if I want to know what portions are random, or the distribution of IO sizes? Do I add another rq-qos policy or add another interface file with interface versioning? Thanks. -- tejun
