#include <linux/latencytop.h>
#include <linux/sched.h>
+#include <linux/cpumask.h>
/*
* Targeted preemption latency for CPU-bound tasks:
/*
* if *imbalance is less than the average load per runnable task
- * there is no gaurantee that any tasks will be moved so we'll have
+ * there is no guarantee that any tasks will be moved so we'll have
* a think about bumping its value to force at least one task to be
* moved
*/
static DEFINE_SPINLOCK(balancing);
+static unsigned long __read_mostly max_load_balance_interval = HZ/10;
+
+/*
+ * Scale the max load_balance interval with the number of CPUs in the system.
+ * This trades load-balance latency on larger machines for less cross talk.
+ */
+static void update_max_interval(void)
+{
+ max_load_balance_interval = HZ*num_online_cpus()/10;
+}
+
/*
* It checks each scheduling domain to see if it is due to be balanced,
* and initiates a balancing operation if so.
/* scale ms to jiffies */
interval = msecs_to_jiffies(interval);
- if (unlikely(!interval))
- interval = 1;
- if (interval > HZ*NR_CPUS/10)
- interval = HZ*NR_CPUS/10;
+ interval = clamp(interval, 1UL, max_load_balance_interval);
need_serialize = sd->flags & SD_SERIALIZE;