Tejun Heo <tj@xxxxxxxxxx> 于2020年3月25日周三 下午10:12写道： > > On Wed, Mar 25, 2020 at 08:49:24PM +0800, Weiping Zhang wrote: > > For this patchset, iotrack can work well, I'm using it to monitor > > block cgroup for > > selecting a proper io isolation policy. > > Yeah, I get that but monitoring needs tend to diverge quite a bit > depending on the use cases making detailed monitoring often need fair > bit of flexibility, so I'm a bit skeptical about adding a fixed > controller for that. I think a better approach may be implementing > features which can make dynamic monitoring whether that's through bpf, > drgn or plain tracepoints easier and more efficient. > I agree with you, there are lots of io metrics needed in the real production system. The more flexible way is export all bio structure members of bio’s whole life to the userspace without re-compiling kernel, like what bpf did. Now the main block cgroup isolation policy: blk-iocost and bfq are weght based, blk-iolatency is latency based. The blk-iotrack can track the real percentage for IOs,kB,on disk time(d2c), and total time, it’s a good indicator to the real weight. For blk-iolatency, the blk-iotrack has 8 lantency thresholds to show latency distribution, so if we change these thresholds around to blk-iolateny.target.latency, we can tune the target latency to a more proper value. blk-iotrack extends the basic io.stat. It just export the important basic io statistics for cgroup,like what /prof/diskstats for block device. And it’s easy programming, iotrack just working like iostat, but focus on cgroup. blk-iotrack is friendly with these block cgroup isolation policies, a indicator for cgroup weight and lantency. Thanks
