On Thu, May 17, 2018 at 04:55:42PM -0400, Waiman Long wrote: > The sched.load_balance flag is needed to enable CPU isolation similar to > what can be done with the "isolcpus" kernel boot parameter. Its value > can only be changed in a scheduling domain with no child cpusets. On > a non-scheduling domain cpuset, the value of sched.load_balance is > inherited from its parent. > > This flag is set by the parent and is not delegatable. > > Signed-off-by: Waiman Long <long...@redhat.com> > --- > Documentation/cgroup-v2.txt | 24 ++++++++++++++++++++ > kernel/cgroup/cpuset.c | 53 > +++++++++++++++++++++++++++++++++++++++++---- > 2 files changed, 73 insertions(+), 4 deletions(-) > > diff --git a/Documentation/cgroup-v2.txt b/Documentation/cgroup-v2.txt > index 54d9e22..071b634d 100644 > --- a/Documentation/cgroup-v2.txt > +++ b/Documentation/cgroup-v2.txt > @@ -1536,6 +1536,30 @@ Cpuset Interface Files > CPUs of the parent cgroup. Once it is set, this flag cannot be > cleared if there are any child cgroups with cpuset enabled. > > + A parent cgroup cannot distribute all its CPUs to child > + scheduling domain cgroups unless its load balancing flag is > + turned off. > + > + cpuset.sched.load_balance > + 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 a non-zero value (on). This flag is set > + by the parent and is not delegatable. > + > + When it is on, tasks within this cpuset will be load-balanced > + by the kernel scheduler. Tasks will be moved from CPUs with > + high load to other CPUs within the same cpuset with less load > + periodically. > + > + When it is off, there will be no load balancing among CPUs on > + this cgroup. Tasks will stay in the CPUs they are running on > + and will not be moved to other CPUs. > + > + The initial value of this flag is "1". This flag is then > + inherited by child cgroups with cpuset enabled. Its state > + can only be changed on a scheduling domain cgroup with no > + cpuset-enabled children.
I'm confused... why exactly do we have both domain and load_balance ?
