Re: [driver-core PATCH v10 6/9] driver core: Attach devices on CPU local to device node

From: Rafael J. Wysocki
Date: Wed Jan 30 2019 - 18:46:53 EST


On Tuesday, January 22, 2019 7:39:37 PM CET Alexander Duyck 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: Dan Williams <dan.j.williams@xxxxxxxxx>
> Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

> ---
> drivers/base/dd.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 627ad05064e0..aa6a9c613595 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -829,7 +829,7 @@ static int __device_attach(struct device *dev, bool allow_async)
> */
> dev_dbg(dev, "scheduling asynchronous probe\n");
> get_device(dev);
> - async_schedule(__device_attach_async_helper, dev);
> + async_schedule_dev(__device_attach_async_helper, dev);
> } else {
> pm_request_idle(dev);
> }
> @@ -989,7 +989,7 @@ static int __driver_attach(struct device *dev, void *data)
> if (!dev->driver) {
> get_device(dev);
> dev->p->async_driver = drv;
> - async_schedule(__driver_attach_async_helper, dev);
> + async_schedule_dev(__driver_attach_async_helper, dev);
> }
> device_unlock(dev);
> return 0;
>
>