summaryrefslogtreecommitdiff
path: root/drivers/base/dd.c
diff options
context:
space:
mode:
authorBhaktipriya Shridhar <bhaktipriya96@gmail.com>2016-08-30 22:45:34 +0530
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-09-02 15:08:02 +0200
commit2c507e464f791327c94d17a0137f00b4717744fc (patch)
tree1e4f42cd773658a9199c731123a96207d4bb35a0 /drivers/base/dd.c
parent775115c06091fcfa1189a50aca488fa596839617 (diff)
device core: Remove deprecated create_singlethread_workqueue
The workqueue "deferred_wq" queues a single work item &deferred_probe_work and hence doesn't require ordering. It is involved in probing devices and is not being used on a memory reclaim path. Hence, it has been converted to use system_wq. System workqueues have been able to handle high level of concurrency for a long time now and hence it's not required to have a singlethreaded workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue created with create_singlethread_workqueue(), system_wq allows multiple work items to overlap executions even on the same CPU; however, a per-cpu workqueue doesn't have any CPU locality or global ordering guarantee unless the target CPU is explicitly specified and thus the increase of local concurrency shouldn't make any difference. The work item has been flushed in driver_probe_done() to ensure that there are no pending tasks while disconnecting the driver. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/dd.c')
-rw-r--r--drivers/base/dd.c12
1 files changed, 3 insertions, 9 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 4910e6db2a34..d22a7260f42b 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -51,7 +51,6 @@
static DEFINE_MUTEX(deferred_probe_mutex);
static LIST_HEAD(deferred_probe_pending_list);
static LIST_HEAD(deferred_probe_active_list);
-static struct workqueue_struct *deferred_wq;
static atomic_t deferred_trigger_count = ATOMIC_INIT(0);
/*
@@ -175,7 +174,7 @@ static void driver_deferred_probe_trigger(void)
* Kick the re-probe thread. It may already be scheduled, but it is
* safe to kick it again.
*/
- queue_work(deferred_wq, &deferred_probe_work);
+ schedule_work(&deferred_probe_work);
}
/**
@@ -211,14 +210,10 @@ void device_unblock_probing(void)
*/
static int deferred_probe_initcall(void)
{
- deferred_wq = create_singlethread_workqueue("deferwq");
- if (WARN_ON(!deferred_wq))
- return -ENOMEM;
-
driver_deferred_probe_enable = true;
driver_deferred_probe_trigger();
/* Sort as many dependencies as possible before exiting initcalls */
- flush_workqueue(deferred_wq);
+ flush_work(&deferred_probe_work);
return 0;
}
late_initcall(deferred_probe_initcall);
@@ -481,8 +476,7 @@ int driver_probe_done(void)
void wait_for_device_probe(void)
{
/* wait for the deferred probe workqueue to finish */
- if (driver_deferred_probe_enable)
- flush_workqueue(deferred_wq);
+ flush_work(&deferred_probe_work);
/* wait for the known devices to complete their probing */
wait_event(probe_waitqueue, atomic_read(&probe_count) == 0);