On Sun, Oct 22, 2023 at 4:50 PM Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> wrote:
On 10/18/23 21:17, Gurchetan Singh wrote:
> There are two problems with the current method of determining the
> virtio-gpu debug name.
>
> 1) TASK_COMM_LEN is defined to be 16 bytes only, and this is a
> Linux kernel idiom (see PR_SET_NAME + PR_GET_NAME). Though,
> Android/FreeBSD get around this via setprogname(..)/getprogname(..)
> in libc.
>
> On Android, names longer than 16 bytes are common. For example,
> one often encounters a program like "com.android.systemui".
>
> The virtio-gpu spec allows the debug name to be up to 64 bytes, so
> ideally userspace should be able to set debug names up to 64 bytes.
>
> 2) The current implementation determines the debug name using whatever
> task initiated virtgpu. This is could be a "RenderThread" of a
> larger program, when we actually want to propagate the debug name
> of the program.
>
> To fix these issues, add a new CONTEXT_INIT param that allows userspace
> to set the debug name when creating a context.
>
> It takes a null-terminated C-string as the param value. The length of the
> string (excluding the terminator) **should** be <= 64 bytes. Otherwise,
> the debug_name will be truncated to 64 bytes.
>
> Link to open-source userspace:
> https://android-review.googlesource.com/c/platform/hardware/google/gfxstream/+/2787176
>
> Signed-off-by: Gurchetan Singh <gurchetansingh@xxxxxxxxxxxx>
> Reviewed-by: Josh Simonot <josh.simonot@xxxxxxxxx>
> ---
> Fixes suggested by Dmitry Osipenko
> v2:
> - Squash implementation and UAPI change into one commit
> - Avoid unnecessary casts
> - Use bool when necessary
> v3:
> - Use DEBUG_NAME_MAX_LEN - 1 when copying string
>
> drivers/gpu/drm/virtio/virtgpu_drv.h | 5 ++++
> drivers/gpu/drm/virtio/virtgpu_ioctl.c | 39 ++++++++++++++++++++++----
> include/uapi/drm/virtgpu_drm.h | 2 ++
> 3 files changed, 40 insertions(+), 6 deletions(-)
Gerd, do you have objections to this UAPI change?
Bump. I say we wait another week and see if anyone cares [I suspect nobody does].
As per DRM guidelines, if there are no open comments and the change is reviewed, it is mergeable.
--
Best regards,
Dmitry
