workqueue: add workqueue->unbound_attrs
Currently, when exposing attrs of an unbound workqueue via sysfs, the
workqueue_attrs of first_pwq() is used as that should equal the
current state of the workqueue.
The planned NUMA affinity support will make unbound workqueues make
use of multiple pool_workqueues for different NUMA nodes and the above
assumption will no longer hold. Introduce workqueue->unbound_attrs
which records the current attrs in effect and use it for sysfs instead
of first_pwq()->attrs.
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 3e18c7b..32b4744 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -244,6 +244,8 @@
int nr_drainers; /* WQ: drain in progress */
int saved_max_active; /* WQ: saved pwq max_active */
+ struct workqueue_attrs *unbound_attrs; /* WQ: only for unbound wqs */
+
#ifdef CONFIG_SYSFS
struct wq_device *wq_dev; /* I: for sysfs interface */
#endif
@@ -3088,10 +3090,9 @@
struct workqueue_struct *wq = dev_to_wq(dev);
int written;
- rcu_read_lock_sched();
- written = scnprintf(buf, PAGE_SIZE, "%d\n",
- first_pwq(wq)->pool->attrs->nice);
- rcu_read_unlock_sched();
+ mutex_lock(&wq->mutex);
+ written = scnprintf(buf, PAGE_SIZE, "%d\n", wq->unbound_attrs->nice);
+ mutex_unlock(&wq->mutex);
return written;
}
@@ -3105,9 +3106,9 @@
if (!attrs)
return NULL;
- rcu_read_lock_sched();
- copy_workqueue_attrs(attrs, first_pwq(wq)->pool->attrs);
- rcu_read_unlock_sched();
+ mutex_lock(&wq->mutex);
+ copy_workqueue_attrs(attrs, wq->unbound_attrs);
+ mutex_unlock(&wq->mutex);
return attrs;
}
@@ -3138,10 +3139,9 @@
struct workqueue_struct *wq = dev_to_wq(dev);
int written;
- rcu_read_lock_sched();
- written = cpumask_scnprintf(buf, PAGE_SIZE,
- first_pwq(wq)->pool->attrs->cpumask);
- rcu_read_unlock_sched();
+ mutex_lock(&wq->mutex);
+ written = cpumask_scnprintf(buf, PAGE_SIZE, wq->unbound_attrs->cpumask);
+ mutex_unlock(&wq->mutex);
written += scnprintf(buf + written, PAGE_SIZE - written, "\n");
return written;
@@ -3558,8 +3558,10 @@
* If we're the last pwq going away, @wq is already dead and no one
* is gonna access it anymore. Free it.
*/
- if (is_last)
+ if (is_last) {
+ free_workqueue_attrs(wq->unbound_attrs);
kfree(wq);
+ }
}
/**
@@ -3634,6 +3636,9 @@
/* link in @pwq */
list_add_rcu(&pwq->pwqs_node, &wq->pwqs);
+ if (wq->flags & WQ_UNBOUND)
+ copy_workqueue_attrs(wq->unbound_attrs, pool->attrs);
+
mutex_unlock(&wq->mutex);
}
@@ -3766,6 +3771,12 @@
if (!wq)
return NULL;
+ if (flags & WQ_UNBOUND) {
+ wq->unbound_attrs = alloc_workqueue_attrs(GFP_KERNEL);
+ if (!wq->unbound_attrs)
+ goto err_free_wq;
+ }
+
vsnprintf(wq->name, namelen, fmt, args1);
va_end(args);
va_end(args1);
@@ -3835,6 +3846,7 @@
return wq;
err_free_wq:
+ free_workqueue_attrs(wq->unbound_attrs);
kfree(wq);
return NULL;
err_destroy: