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Message-ID: <1412740423-20782-2-git-send-email-laijs@cn.fujitsu.com>
Date: Wed, 8 Oct 2014 11:53:31 +0800
From: Lai Jiangshan <laijs@...fujitsu.com>
To: <linux-kernel@...r.kernel.org>, Tejun Heo <tj@...nel.org>
CC: Lai Jiangshan <laijs@...fujitsu.com>
Subject: [PATCH 1/3] workqueue: add wq_unbound_online_cpumask
Current wq_calc_node_cpumask() is complicated by cpumask_of_node(node) whose
value need to be revised before using and the "revising" needs @cpu_going_down
which makes more complicated.
This patch introduces wq_unbound_online_cpumask which is updated before
wq_update_unbound_numa() in the cpu-hotplug callbacks and wq_calc_node_cpumask()
can use it instead of cpumask_of_node(node). Thus wq_calc_node_cpumask()
becomes much simpler and @cpu_going_down is gone.
Signed-off-by: Lai Jiangshan <laijs@...fujitsu.com>
---
kernel/workqueue.c | 42 ++++++++++++++++++++----------------------
1 files changed, 20 insertions(+), 22 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 5dbe22a..7a217f0 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -282,6 +282,9 @@ module_param_named(power_efficient, wq_power_efficient, bool, 0444);
static bool wq_numa_enabled; /* unbound NUMA affinity enabled */
+/* PL: online cpumask for all unbound wqs */
+static struct cpumask wq_unbound_online_cpumask;
+
/* buf for wq_update_unbound_numa_attrs(), protected by CPU hotplug exclusion */
static struct workqueue_attrs *wq_update_unbound_numa_attrs_buf;
@@ -3675,12 +3678,9 @@ static void free_unbound_pwq(struct pool_workqueue *pwq)
* wq_calc_node_mask - calculate a wq_attrs' cpumask for the specified node
* @attrs: the wq_attrs of interest
* @node: the target NUMA node
- * @cpu_going_down: if >= 0, the CPU to consider as offline
* @cpumask: outarg, the resulting cpumask
*
- * Calculate the cpumask a workqueue with @attrs should use on @node. If
- * @cpu_going_down is >= 0, that cpu is considered offline during
- * calculation. The result is stored in @cpumask.
+ * Calculate the cpumask a workqueue with @attrs should use on @node.
*
* If NUMA affinity is not enabled, @attrs->cpumask is always used. If
* enabled and @node has online CPUs requested by @attrs, the returned
@@ -3694,22 +3694,17 @@ static void free_unbound_pwq(struct pool_workqueue *pwq)
* %false if equal.
*/
static bool wq_calc_node_cpumask(const struct workqueue_attrs *attrs, int node,
- int cpu_going_down, cpumask_t *cpumask)
+ struct cpumask *cpumask)
{
if (!wq_numa_enabled || attrs->no_numa)
goto use_dfl;
/* does @node have any online CPUs @attrs wants? */
- cpumask_and(cpumask, cpumask_of_node(node), attrs->cpumask);
- if (cpu_going_down >= 0)
- cpumask_clear_cpu(cpu_going_down, cpumask);
-
- if (cpumask_empty(cpumask))
- goto use_dfl;
-
- /* yeap, return possible CPUs in @node that @attrs wants */
cpumask_and(cpumask, attrs->cpumask, wq_numa_possible_cpumask[node]);
- return !cpumask_equal(cpumask, attrs->cpumask);
+ if (cpumask_intersects(cpumask, &wq_unbound_online_cpumask)) {
+ /* yeap, return possible CPUs in @node that @attrs wants */
+ return !cpumask_equal(cpumask, attrs->cpumask);
+ }
use_dfl:
cpumask_copy(cpumask, attrs->cpumask);
@@ -3800,7 +3795,7 @@ int apply_workqueue_attrs(struct workqueue_struct *wq,
goto enomem_pwq;
for_each_node(node) {
- if (wq_calc_node_cpumask(attrs, node, -1, tmp_attrs->cpumask)) {
+ if (wq_calc_node_cpumask(attrs, node, tmp_attrs->cpumask)) {
pwq_tbl[node] = alloc_unbound_pwq(wq, tmp_attrs);
if (!pwq_tbl[node])
goto enomem_pwq;
@@ -3857,7 +3852,6 @@ enomem:
* wq_update_unbound_numa - update NUMA affinity of a wq for CPU hot[un]plug
* @wq: the target workqueue
* @cpu: the CPU coming up or going down
- * @online: whether @cpu is coming up or going down
*
* This function is to be called from %CPU_DOWN_PREPARE, %CPU_ONLINE and
* %CPU_DOWN_FAILED. @cpu is being hot[un]plugged, update NUMA affinity of
@@ -3875,11 +3869,9 @@ enomem:
* affinity, it's the user's responsibility to flush the work item from
* CPU_DOWN_PREPARE.
*/
-static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu,
- bool online)
+static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu)
{
int node = cpu_to_node(cpu);
- int cpu_off = online ? -1 : cpu;
struct pool_workqueue *old_pwq = NULL, *pwq;
struct workqueue_attrs *target_attrs;
cpumask_t *cpumask;
@@ -3910,7 +3902,7 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu,
* a new one if they don't match. If the target cpumask equals
* wq's, the default pwq should be used.
*/
- if (wq_calc_node_cpumask(wq->unbound_attrs, node, cpu_off, cpumask)) {
+ if (wq_calc_node_cpumask(wq->unbound_attrs, node, cpumask)) {
if (cpumask_equal(cpumask, pwq->pool->attrs->cpumask))
goto out_unlock;
} else {
@@ -4583,9 +4575,11 @@ static int workqueue_cpu_up_callback(struct notifier_block *nfb,
mutex_unlock(&pool->attach_mutex);
}
+ cpumask_set_cpu(cpu, &wq_unbound_online_cpumask);
+
/* update NUMA affinity of unbound workqueues */
list_for_each_entry(wq, &workqueues, list)
- wq_update_unbound_numa(wq, cpu, true);
+ wq_update_unbound_numa(wq, cpu);
mutex_unlock(&wq_pool_mutex);
break;
@@ -4611,10 +4605,12 @@ static int workqueue_cpu_down_callback(struct notifier_block *nfb,
INIT_WORK_ONSTACK(&unbind_work, wq_unbind_fn);
queue_work_on(cpu, system_highpri_wq, &unbind_work);
+ cpumask_clear_cpu(cpu, &wq_unbound_online_cpumask);
+
/* update NUMA affinity of unbound workqueues */
mutex_lock(&wq_pool_mutex);
list_for_each_entry(wq, &workqueues, list)
- wq_update_unbound_numa(wq, cpu, false);
+ wq_update_unbound_numa(wq, cpu);
mutex_unlock(&wq_pool_mutex);
/* wait for per-cpu unbinding to finish */
@@ -4828,6 +4824,8 @@ static int __init init_workqueues(void)
pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);
+ cpumask_copy(&wq_unbound_online_cpumask, cpu_online_mask);
+
cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP);
hotcpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN);
--
1.7.4.4
--
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