Merge tag 'driver-core-4.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git...

[cascardo/linux.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 94732d1..42d4027 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7515,11 +7515,27 @@ static struct kmem_cache *task_group_cache __read_mostly;
 DECLARE_PER_CPU(cpumask_var_t, load_balance_mask);
 DECLARE_PER_CPU(cpumask_var_t, select_idle_mask);
 
+#define WAIT_TABLE_BITS 8
+#define WAIT_TABLE_SIZE (1 << WAIT_TABLE_BITS)
+static wait_queue_head_t bit_wait_table[WAIT_TABLE_SIZE] __cacheline_aligned;
+
+wait_queue_head_t *bit_waitqueue(void *word, int bit)
+{
+       const int shift = BITS_PER_LONG == 32 ? 5 : 6;
+       unsigned long val = (unsigned long)word << shift | bit;
+
+       return bit_wait_table + hash_long(val, WAIT_TABLE_BITS);
+}
+EXPORT_SYMBOL(bit_waitqueue);
+
 void __init sched_init(void)
 {
        int i, j;
        unsigned long alloc_size = 0, ptr;
 
+       for (i = 0; i < WAIT_TABLE_SIZE; i++)
+               init_waitqueue_head(bit_wait_table + i);
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
        alloc_size += 2 * nr_cpu_ids * sizeof(void **);
 #endif