On 05/30/2018 10:18 AM, Juri Lelli wrote: > Hi, > > On 29/05/18 09:41, Waiman Long wrote: > > [...] > >> + cpuset.sched.domain_root >> + A read-write single value file which exists on non-root >> + cpuset-enabled cgroups. It is a binary value flag that accepts >> + either "0" (off) or "1" (on). This flag is set by the parent >> + and is not delegatable. >> + >> + If set, it indicates that the current cgroup is the root of a >> + new scheduling domain or partition that comprises itself and >> + all its descendants except those that are scheduling domain >> + roots themselves and their descendants. The root cgroup is >> + always a scheduling domain root. >> + >> + There are constraints on where this flag can be set. It can >> + only be set in a cgroup if all the following conditions are true. >> + >> + 1) The "cpuset.cpus" is not empty and the list of CPUs are >> + exclusive, i.e. they are not shared by any of its siblings. >> + 2) The parent cgroup is also a scheduling domain root. >> + 3) There is no child cgroups with cpuset enabled. This is >> + for eliminating corner cases that have to be handled if such >> + a condition is allowed. >> + >> + Setting this flag will take the CPUs away from the effective >> + CPUs of the parent cgroup. Once it is set, this flag cannot >> + be cleared if there are any child cgroups with cpuset enabled. >> + Further changes made to "cpuset.cpus" is allowed as long as >> + the first condition above is still true. > IIUC, with the configuration below > > cpuset.cpus.effective:6-11 > cgroup.controllers:cpuset > cpuset.mems.effective:0-1 > cgroup.subtree_control:cpuset > g1/cpuset.cpus.effective:0-5 > g1/cgroup.controllers:cpuset > g1/cpuset.sched.load_balance:1 > g1/cpuset.mems.effective:0-1 > g1/cpuset.cpus:0-5 > g1/cpuset.sched.domain_root:1 > user.slice/cpuset.cpus.effective:6-11 > user.slice/cgroup.controllers:cpuset > user.slice/cpuset.sched.load_balance:1 > user.slice/cpuset.mems.effective:0-1 > user.slice/cpuset.cpus:6-11 > user.slice/cpuset.sched.domain_root:0 > init.scope/cpuset.cpus.effective:6-11 > init.scope/cgroup.controllers:cpuset > init.scope/cpuset.sched.load_balance:1 > init.scope/cpuset.mems.effective:0-1 > init.scope/cpuset.cpus:6-11 > init.scope/cpuset.sched.domain_root:0 > system.slice/cpuset.cpus.effective:6-11 > system.slice/cgroup.controllers:cpuset > system.slice/cpuset.sched.load_balance:1 > system.slice/cpuset.mems.effective:0-1 > system.slice/cpuset.cpus:6-11 > system.slice/cpuset.sched.domain_root:0 > machine.slice/cpuset.cpus.effective:6-11 > machine.slice/cgroup.controllers:cpuset > machine.slice/cpuset.sched.load_balance:1 > machine.slice/cpuset.mems.effective:0-1 > machine.slice/cpuset.cpus:6-11 > machine.slice/cpuset.sched.domain_root:0 > > I should be able to > > # echo 0-4 >g1/cpuset.cpus > > ? > > It doesn't let me. It should allow that. I will fix this issue. > > I'm not sure we actually want to allow that, but that's what would I > expect as per your text above. > > Thanks, > > - Juri > > BTW: thanks a lot for your prompt feedback and hope it's OK if I keep > playing and asking questions. :) Of course. I appreciate your help in looking for issue in the patch that I might have overlooked. Thanks, Longman -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
