On 3/26/20 4:23 PM, Joel Fernandes wrote: > On Thu, Mar 26, 2020 at 04:18:59PM -0400, Tejun Heo wrote: >> On Thu, Mar 26, 2020 at 01:05:04PM -0700, Sonny Rao wrote: >>> I am surprised if anyone actually wants this behavior, we (Chrome >>> OS) >> >> The behavior is silly but consistent in that it doesn't allow empty >> active cpusets and it has been like that for many many years now. >> >>> found out about it accidentally, and then found that Android had >>> been carrying a patch to fix it. And if it were a desirable >>> behavior then why isn't it an option in v2? >> >> Nobody is saying it's a good behavior (hence the change in cgroup2) >> and there are situations where changing things like this is >> justifiable, but, here: >> >> * The proposed change makes the interface inconsistent and does so >> unconditionally on what is now a mostly legacy interface. >> >> * There already is a newer version of the interface which includes >> the desired behavior. >> >> * I forgot but as Waiman pointed out, you can even opt-in to the >> new behavior, which is more comprehensive without the >> inconsitencies, while staying on cgroup1. > > Thank you Tejun, Waiman and Sonny. I confirmed the cgroup_v2_mode > option fixes cgroup v1's broken behavior. > > We will use this mount option on our systems to fix it. I am glad that it works for you. I think the problem is that the v2_mode mount option is not that well documented. Maybe I should send a patch to add some some description about it in cgroup-v2.rst or cgroup-v1/cpusets.rst. Cheers, Longman
