workqueue: add wq_numa_tbl_len and wq_numa_possible_cpumask[]
Unbound workqueues are going to be NUMA-affine. Add wq_numa_tbl_len
and wq_numa_possible_cpumask[] in preparation. The former is the
highest NUMA node ID + 1 and the latter is masks of possibles CPUs for
each NUMA node.
This patch only introduces these. Future patches will make use of
them.
v2: NUMA initialization move into wq_numa_init(). Also, the possible
cpumask array is not created if there aren't multiple nodes on the
system. wq_numa_enabled bool added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 2bf3d8c..5ca46a2 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -44,6 +44,7 @@
#include <linux/jhash.h>
#include <linux/hashtable.h>
#include <linux/rculist.h>
+#include <linux/nodemask.h>
#include "workqueue_internal.h"
@@ -253,6 +254,12 @@
static struct kmem_cache *pwq_cache;
+static int wq_numa_tbl_len; /* highest possible NUMA node id + 1 */
+static cpumask_var_t *wq_numa_possible_cpumask;
+ /* possible CPUs of each node */
+
+static bool wq_numa_enabled; /* unbound NUMA affinity enabled */
+
static DEFINE_MUTEX(wq_pool_mutex); /* protects pools and workqueues list */
static DEFINE_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */
@@ -4407,6 +4414,43 @@
}
#endif /* CONFIG_FREEZER */
+static void __init wq_numa_init(void)
+{
+ cpumask_var_t *tbl;
+ int node, cpu;
+
+ /* determine NUMA pwq table len - highest node id + 1 */
+ for_each_node(node)
+ wq_numa_tbl_len = max(wq_numa_tbl_len, node + 1);
+
+ if (num_possible_nodes() <= 1)
+ return;
+
+ /*
+ * We want masks of possible CPUs of each node which isn't readily
+ * available. Build one from cpu_to_node() which should have been
+ * fully initialized by now.
+ */
+ tbl = kzalloc(wq_numa_tbl_len * sizeof(tbl[0]), GFP_KERNEL);
+ BUG_ON(!tbl);
+
+ for_each_node(node)
+ BUG_ON(!alloc_cpumask_var_node(&tbl[node], GFP_KERNEL, node));
+
+ for_each_possible_cpu(cpu) {
+ node = cpu_to_node(cpu);
+ if (WARN_ON(node == NUMA_NO_NODE)) {
+ pr_warn("workqueue: NUMA node mapping not available for cpu%d, disabling NUMA support\n", cpu);
+ /* happens iff arch is bonkers, let's just proceed */
+ return;
+ }
+ cpumask_set_cpu(cpu, tbl[node]);
+ }
+
+ wq_numa_possible_cpumask = tbl;
+ wq_numa_enabled = true;
+}
+
static int __init init_workqueues(void)
{
int std_nice[NR_STD_WORKER_POOLS] = { 0, HIGHPRI_NICE_LEVEL };
@@ -4423,6 +4467,8 @@
cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP);
hotcpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN);
+ wq_numa_init();
+
/* initialize CPU pools */
for_each_possible_cpu(cpu) {
struct worker_pool *pool;