diff options
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 11 | ||||
| -rw-r--r-- | kernel/cgroup/cpuset.c | 6 |
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; } |