Re: [PATCH v6] mm/hmm/test: use char dev with struct device to get device node

[Jason Gunthorpe <jgg@ziepe.ca>]

On Wed, Mar 30, 2022 at 03:47:25AM +0300, mpenttil@redhat.com wrote:
> From: Mika Penttilä <mpenttil@redhat.com>
> 
> HMM selftests use an in-kernel pseudo device to emulate device private
> memory. The pseudo device registers a major device range for two pseudo
> device instances. User space has a script that reads /proc/devices in
> order to find the assigned major number, and sends that to mknod(1),
> once for each node.
> 
> Change this to properly use cdev and struct device APIs.
> 
> Delete the /proc/devices parsing from the user-space test script, now
> that it is unnecessary.
> 
> Also, deleted an unused field in struct dmirror_device: devmem.
> 
> Signed-off-by: Mika Penttilä <mpenttil@redhat.com>
> Reviewed-by: John Hubbard <jhubbard@nvidia.com>
> Cc: Alistair Popple <apopple@nvidia.com>
> Cc: Ralph Campbell <rcampbell@nvidia.com>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> ---
> v6:
>         - remove device names array
>         - check return value of dev_set_name()
> v5:
>         - fix whitespace
>         . delete unused structure field
> v4:
>         - fix commit log
> v3:
>         - use cdev_device_add() instead of miscdevice
> v2:
>         - Cleanups per review comments from John Hubbard
>         - Added Tested-by and Ccs
> 
> 
>  lib/test_hmm.c                         | 13 ++++++++++---
>  tools/testing/selftests/vm/test_hmm.sh |  6 ------
>  2 files changed, 10 insertions(+), 9 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason