From: Zefan Li <[email protected]> [ Upstream commit 79063bffc81f82689bd90e16da1b49408f3bf095 ]
When we clear cpuset.cpus, cpuset.effective_cpus won't be cleared: # mount -t cgroup -o cpuset xxx /mnt # mkdir /mnt/tmp # echo 0 > /mnt/tmp/cpuset.cpus # echo > /mnt/tmp/cpuset.cpus # cat cpuset.cpus # cat cpuset.effective_cpus 0-15 And a kernel warning in update_cpumasks_hier() is triggered: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 4028 at kernel/cpuset.c:894 update_cpumasks_hier+0x471/0x650() Cc: <[email protected]> # 3.17+ Signed-off-by: Zefan Li <[email protected]> Signed-off-by: Tejun Heo <[email protected]> Tested-by: Serge Hallyn <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- kernel/cpuset.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 7e59b7b..d492162 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -863,7 +863,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus) * If it becomes empty, inherit the effective mask of the * parent, which is guaranteed to have some CPUs. */ - if (cpumask_empty(new_cpus)) + if (cgroup_on_dfl(cp->css.cgroup) && cpumask_empty(new_cpus)) cpumask_copy(new_cpus, parent->effective_cpus); /* Skip the whole subtree if the cpumask remains the same. */ @@ -1119,7 +1119,7 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems) * If it becomes empty, inherit the effective mask of the * parent, which is guaranteed to have some MEMs. */ - if (nodes_empty(*new_mems)) + if (cgroup_on_dfl(cp->css.cgroup) && nodes_empty(*new_mems)) *new_mems = parent->effective_mems; /* Skip the whole subtree if the nodemask remains the same. */ -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
