diff options
Diffstat (limited to 'kernel/cpuset.c')
| -rw-r--r-- | kernel/cpuset.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 584bb4e6c042..794af5024c2f 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -912,6 +912,10 @@ static int update_nodemask(struct cpuset *cs, char *buf) int fudge; int retval; + /* top_cpuset.mems_allowed tracks node_online_map; it's read-only */ + if (cs == &top_cpuset) + return -EACCES; + trialcs = *cs; retval = nodelist_parse(buf, trialcs.mems_allowed); if (retval < 0) @@ -2042,9 +2046,8 @@ out: * (of no affect) on systems that are actively using CPU hotplug * but making no active use of cpusets. * - * This handles CPU hotplug (cpuhp) events. If someday Memory - * Nodes can be hotplugged (dynamically changing node_online_map) - * then we should handle that too, perhaps in a similar way. + * This routine ensures that top_cpuset.cpus_allowed tracks + * cpu_online_map on each CPU hotplug (cpuhp) event. */ #ifdef CONFIG_HOTPLUG_CPU @@ -2063,6 +2066,25 @@ static int cpuset_handle_cpuhp(struct notifier_block *nb, } #endif +/* + * Keep top_cpuset.mems_allowed tracking node_online_map. + * Call this routine anytime after you change node_online_map. + * See also the previous routine cpuset_handle_cpuhp(). + */ + +#ifdef CONFIG_MEMORY_HOTPLUG +void cpuset_track_online_nodes() +{ + mutex_lock(&manage_mutex); + mutex_lock(&callback_mutex); + + top_cpuset.mems_allowed = node_online_map; + + mutex_unlock(&callback_mutex); + mutex_unlock(&manage_mutex); +} +#endif + /** * cpuset_init_smp - initialize cpus_allowed * |