diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 1fcec89a28b9..98af44a7f399 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -152,6 +152,12 @@ static cpumask_var_t isolated_cpus; /* CSCB */ */ static bool update_housekeeping; /* RWCS */ +/* + * Set if "cpuset_v2_mode" mount option is used + * Cached at bind time and not lock protected; accessed via {READ,WRITE}_ONCE + */ +static bool cpuset_v2_mode; + /* * Copy of isolated_cpus to be passed to housekeeping_update() */ @@ -439,8 +445,7 @@ static inline bool cpuset_v2(void) */ static inline bool is_in_v2_mode(void) { - return cpuset_v2() || - (cpuset_cgrp_subsys.root->flags & CGRP_ROOT_CPUSET_V2_MODE); + return cpuset_v2() || READ_ONCE(cpuset_v2_mode); } /** @@ -3727,6 +3732,8 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css) mutex_lock(&cpuset_mutex); spin_lock_irq(&callback_lock); + WRITE_ONCE(cpuset_v2_mode, + !!(cpuset_cgrp_subsys.root->flags & CGRP_ROOT_CPUSET_V2_MODE)); if (is_in_v2_mode()) { cpumask_copy(top_cpuset.cpus_allowed, cpu_possible_mask); cpumask_copy(top_cpuset.effective_xcpus, cpu_possible_mask);