cpuset: allow writing offlined masks to cpuset.cpus/mems

As the configured masks won't be limited by its parent, and the top
cpuset's masks won't change when hotplug happens, it's natural to
allow writing offlined masks to the configured masks.

If on default hierarchy:

	# echo 0 > /sys/devices/system/cpu/cpu1/online
	# mkdir /cpuset/sub
	# echo 1 > /cpuset/sub/cpuset.cpus
	# cat /cpuset/sub/cpuset.cpus
	1

If on legacy hierarchy:

	# echo 0 > /sys/devices/system/cpu/cpu1/online
	# mkdir /cpuset/sub
	# echo 1 > /cpuset/sub/cpuset.cpus
	-bash: echo: write error: Invalid argument

Note the checks don't need to be gated by cgroup_on_dfl, because we've
initialized top_cpuset.{cpus,mems}_allowed accordingly in cpuset_bind().

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Li Zefan 2014-07-09 16:49:12 +08:00 committed by Tejun Heo
parent be4c9dd7ae
commit 5d8ba82c3a

View file

@ -929,7 +929,8 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
if (retval < 0)
return retval;
if (!cpumask_subset(trialcs->cpus_allowed, cpu_active_mask))
if (!cpumask_subset(trialcs->cpus_allowed,
top_cpuset.cpus_allowed))
return -EINVAL;
}
@ -1186,8 +1187,8 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
goto done;
if (!nodes_subset(trialcs->mems_allowed,
node_states[N_MEMORY])) {
retval = -EINVAL;
top_cpuset.mems_allowed)) {
retval = -EINVAL;
goto done;
}
}