summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--Documentation/admin-guide/cgroup-v2.rst11
-rw-r--r--kernel/cgroup/cpuset.c6
2 files changed, 16 insertions, 1 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 5c7377b5bd3e..babbe04c8d37 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -2056,6 +2056,17 @@ Cpuset Interface Files
The value of "cpuset.mems" stays constant until the next update
and won't be affected by any memory nodes hotplug events.
+ Setting a non-empty value to "cpuset.mems" causes memory of
+ tasks within the cgroup to be migrated to the designated nodes if
+ they are currently using memory outside of the designated nodes.
+
+ There is a cost for this memory migration. The migration
+ may not be complete and some memory pages may be left behind.
+ So it is recommended that "cpuset.mems" should be set properly
+ before spawning new tasks into the cpuset. Even if there is
+ a need to change "cpuset.mems" with active tasks, it shouldn't
+ be done frequently.
+
cpuset.mems.effective
A read-only multiple values file which exists on all
cpuset-enabled cgroups.
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index fcc11f2d3b5b..44d234b0df5e 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -2761,12 +2761,16 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
return ERR_PTR(-ENOMEM);
}
- set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
+ __set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
nodes_clear(cs->mems_allowed);
nodes_clear(cs->effective_mems);
fmeter_init(&cs->fmeter);
cs->relax_domain_level = -1;
+ /* Set CS_MEMORY_MIGRATE for default hierarchy */
+ if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys))
+ __set_bit(CS_MEMORY_MIGRATE, &cs->flags);
+
return &cs->css;
}