On Fri, Jul 5, 2019 at 11:11 PM Brian Foster <bfoster@xxxxxxxxxx> wrote: > > cc linux-xfs > > On Fri, Jul 05, 2019 at 10:33:04PM +0800, Yafang Shao wrote: > > On Fri, Jul 5, 2019 at 7:10 PM Michal Hocko <mhocko@xxxxxxxxxx> wrote: > > > > > > On Fri 05-07-19 17:41:44, Yafang Shao wrote: > > > > On Fri, Jul 5, 2019 at 5:09 PM Michal Hocko <mhocko@xxxxxxxxxx> wrote: > > > [...] > > > > > Why cannot you move over to v2 and have to stick with v1? > > > > Because the interfaces between cgroup v1 and cgroup v2 are changed too > > > > much, which is unacceptable by our customer. > > > > > > Could you be more specific about obstacles with respect to interfaces > > > please? > > > > > > > Lots of applications will be changed. > > Kubernetes, Docker and some other applications which are using cgroup v1, > > that will be a trouble, because they are not maintained by us. > > > > > > It may take long time to use cgroup v2 in production envrioment, per > > > > my understanding. > > > > BTW, the filesystem on our servers is XFS, but the cgroup v2 > > > > writeback throttle is not supported on XFS by now, that is beyond my > > > > comprehension. > > > > > > Are you sure? I would be surprised if v1 throttling would work while v2 > > > wouldn't. As far as I remember it is v2 writeback throttling which > > > actually works. The only throttling we have for v1 is reclaim based one > > > which is a huge hammer. > > > -- > > > > We did it in cgroup v1 in our kernel. > > But the upstream still don't support it in cgroup v2. > > So my real question is why upstream can't support such an import file system ? > > Do you know which companies besides facebook are using cgroup v2 in > > their product enviroment? > > > > I think the original issue with regard to XFS cgroupv2 writeback > throttling support was that at the time the XFS patch was proposed, > there wasn't any test coverage to prove that the code worked (and the > original author never followed up). That has since been resolved and > Christoph has recently posted a new patch [1], which appears to have > been accepted by the maintainer. > > Brian > > [1] https://marc.info/?l=linux-xfs&m=156138379906141&w=2 > Thanks for your reference. I will pay attention to that thread.
