| Message ID | 20160702083923.GA27352@Karyakshetra (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Jul 02, 2016 at 02:09:23PM +0530, Bhaktipriya Shridhar wrote: > The workqueue "esd_wq" has only a single workitem(&md->esd_work) > and hence doesn't require ordering. Also, it is not being used on a > memory reclaim path. Hence, the singlethreaded workqueue has been > replaced with the use of 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. > > mipid_esd_stop_check () calls cancel_delayed_work() in mipid_cleanup() > 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> Thanks.
On 02/07/16 11:39, Bhaktipriya Shridhar wrote: > The workqueue "esd_wq" has only a single workitem(&md->esd_work) > and hence doesn't require ordering. Also, it is not being used on a > memory reclaim path. Hence, the singlethreaded workqueue has been > replaced with the use of 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. > > mipid_esd_stop_check () calls cancel_delayed_work() in mipid_cleanup() > to ensure that there are no pending tasks while disconnecting the driver. > > Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> > --- > drivers/video/fbdev/omap/lcd_mipid.c | 9 +-------- > 1 file changed, 1 insertion(+), 8 deletions(-) Thanks, queued for v4.9. Tomi
diff --git a/drivers/video/fbdev/omap/lcd_mipid.c b/drivers/video/fbdev/omap/lcd_mipid.c index 0e4cee9..c81f150 100644 --- a/drivers/video/fbdev/omap/lcd_mipid.c +++ b/drivers/video/fbdev/omap/lcd_mipid.c @@ -60,7 +60,6 @@ struct mipid_device { struct mutex mutex; struct lcd_panel panel; - struct workqueue_struct *esd_wq; struct delayed_work esd_work; void (*esd_check)(struct mipid_device *m); }; @@ -390,7 +389,7 @@ static void ls041y3_esd_check(struct mipid_device *md) static void mipid_esd_start_check(struct mipid_device *md) { if (md->esd_check != NULL) - queue_delayed_work(md->esd_wq, &md->esd_work, + schedule_delayed_work(&md->esd_work, MIPID_ESD_CHECK_PERIOD); } @@ -476,11 +475,6 @@ static int mipid_init(struct lcd_panel *panel, struct mipid_device *md = to_mipid_device(panel); md->fbdev = fbdev; - md->esd_wq = create_singlethread_workqueue("mipid_esd"); - if (md->esd_wq == NULL) { - dev_err(&md->spi->dev, "can't create ESD workqueue\n"); - return -ENOMEM; - } INIT_DELAYED_WORK(&md->esd_work, mipid_esd_work); mutex_init(&md->mutex); @@ -500,7 +494,6 @@ static void mipid_cleanup(struct lcd_panel *panel) if (md->enabled) mipid_esd_stop_check(md); - destroy_workqueue(md->esd_wq); } static struct lcd_panel mipid_panel = {
The workqueue "esd_wq" has only a single workitem(&md->esd_work) and hence doesn't require ordering. Also, it is not being used on a memory reclaim path. Hence, the singlethreaded workqueue has been replaced with the use of 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. mipid_esd_stop_check () calls cancel_delayed_work() in mipid_cleanup() to ensure that there are no pending tasks while disconnecting the driver. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> --- drivers/video/fbdev/omap/lcd_mipid.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html