Messages in this thread |  | | Date | Mon, 27 Aug 2018 09:40:04 -0700 | From | Tejun Heo <> | Subject | Re: [PATCH v12 9/9] cpuset: Support forced turning off of partition flag |
| |
Hello, Waiman.
On Mon, Aug 27, 2018 at 10:41:24AM -0400, Waiman Long wrote: > Cpuset allows arbitrary modification of cpu list in "cpuset.cpus" > even if the requested CPUs won't be granted in "cpuset.cpus.effective" > as restricted by its parent. However, the validate_change() function > will inhibit removal of CPUs that have been used in child cpusets. > > Being a partition root, however, limits the kind of cpu list > modification that is allowed. Adding CPUs is not allowed if the new > CPUs are not in the parent's effective cpu list that can be put into > "cpuset.cpus.reserved". In addition, a child partition cannot exhaust > all the parent's effective CPUs. > > Because of the implicit cpu exclusive nature of the partition root, > cpu changes that break that cpu exclusivity will not be allowed. Other > changes that break the conditions of being a partition root is generally > allowed. However, the partition flag of the cpuset as well those of > the descendant partitions will be forcefully turned off.
First of all, thanks a lot for your persistence. I'm not necessarily against the flag being forced off but wonder whether the same config/effective approach can be used as in .cpus and .mems. Can you elaborate a bit on the choice here?
Thank you.
-- tejun
|  |