[driver-core,v6,7/9] driver core: Attach devices on CPU local to device node

Commit Message

Alexander Duyck Nov. 8, 2018, 6:07 p.m. UTC

Call the asynchronous probe routines on a CPU local to the device node. By
doing this we should be able to improve our initialization time
significantly as we can avoid having to access the device from a remote
node which may introduce higher latency.

For example, in the case of initializing memory for NVDIMM this can have a
significant impact as initialing 3TB on remote node can take up to 39
seconds while initialing it on a local node only takes 23 seconds. It is
situations like this where we will see the biggest improvement.

Reviewed-by: Bart Van Assche <[e-mail]>
Signed-off-by: Alexander Duyck <[e-mail]>
---
 drivers/base/dd.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Dan Williams Nov. 27, 2018, 4:50 a.m. UTC | #1

On Thu, Nov 8, 2018 at 10:07 AM Alexander Duyck
<[e-mail]> wrote:
>
> Call the asynchronous probe routines on a CPU local to the device node. By
> doing this we should be able to improve our initialization time
> significantly as we can avoid having to access the device from a remote
> node which may introduce higher latency.
>
> For example, in the case of initializing memory for NVDIMM this can have a
> significant impact as initialing 3TB on remote node can take up to 39
> seconds while initialing it on a local node only takes 23 seconds. It is
> situations like this where we will see the biggest improvement.
>
> Reviewed-by: Bart Van Assche <[e-mail]>
> Signed-off-by: Alexander Duyck <[e-mail]>

Looks good,

Reviewed-by: Dan Williams <[e-mail]>

Patch

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index f4e84d639c69..1660eeb1fc9d 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -834,7 +834,7 @@  static int __device_attach(struct device *dev, bool allow_async)
 			dev_dbg(dev, "scheduling asynchronous probe\n");
 			get_device(dev);
 			dev->async_probe = true;
-			async_schedule(__device_attach_async_helper, dev);
+			async_schedule_dev(__device_attach_async_helper, dev);
 		} else {
 			pm_request_idle(dev);
 		}
@@ -1008,7 +1008,7 @@  static int __driver_attach(struct device *dev, void *data)
 		if (!dev->driver) {
 			get_device(dev);
 			dev_set_drv_async(dev, drv);
-			async_schedule(__driver_attach_async_helper, dev);
+			async_schedule_dev(__driver_attach_async_helper, dev);
 		}
 		device_unlock(dev);
 		return 0;