[PATCH RFC 05/12] sched/core: Dynamic update housekeeping_cpumask(HK_TYPE_DOMAIN)

[Qiliang Yuan <realwujing@gmail.com>]

The housekeeping mask for scheduler domains (HK_TYPE_DOMAIN) is used to
determine which CPUs are isolated from the general scheduler load
balancing. When this mask is updated at runtime, we need to rebuild
the scheduler domains to reflect the new isolation boundaries.

Register a housekeeping notifier in the scheduler core to trigger
rebuild_sched_domains() when the HK_TYPE_DOMAIN mask changes.

Signed-off-by: Qiliang Yuan <realwujing@gmail.com>
Signed-off-by: Qiliang Yuan <yuanql9@chinatelecom.cn>
---
 kernel/sched/topology.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index cf643a5ddedd..7f218fc62183 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/sched/isolation.h>
+#include <linux/cpuset.h>
 #include <linux/bsearch.h>
 #include "sched.h"
 
@@ -2940,3 +2941,28 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
 	partition_sched_domains_locked(ndoms_new, doms_new, dattr_new);
 	sched_domains_mutex_unlock();
 }
+
+static int sched_housekeeping_reconfigure(struct notifier_block *nb,
+					 unsigned long action, void *data)
+{
+	if (action == HK_UPDATE_MASK) {
+		unsigned int type = (unsigned long)data;
+
+		if (type == HK_TYPE_DOMAIN)
+			rebuild_sched_domains();
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block sched_housekeeping_nb = {
+	.notifier_call = sched_housekeeping_reconfigure,
+};
+
+static int __init sched_housekeeping_init(void)
+{
+	housekeeping_register_notifier(&sched_housekeeping_nb);
+	return 0;
+}
+core_initcall(sched_housekeeping_init);
+

-- 
2.51.0