On 24.04.2017 18:20, Andres Rodriguez wrote:
> Add a new context creation parameter to express a global context priority.
>
> The priority ranking in descending order is as follows:
> * AMDGPU_CTX_PRIORITY_HIGH
> * AMDGPU_CTX_PRIORITY_NORMAL
> * AMDGPU_CTX_PRIORITY_LOW
>
> The driver will attempt to schedule work to the hardware according to
> the priorities. No latency or throughput guarantees are provided by
> this patch.
>
> This interface intends to service the EGL_IMG_context_priority
> extension, and vulkan equivalents.
>
> v2: Instead of using flags, repurpose __pad
> v3: Swap enum values of _NORMAL _HIGH for backwards compatibility
> v4: Validate usermode priority and store it
> v5: Move priority validation into amdgpu_ctx_ioctl(), headline reword
> v6: add UAPI note regarding priorities requiring CAP_SYS_ADMIN
> v7: remove ctx->priority
> v8: added AMDGPU_CTX_PRIORITY_LOW, s/CAP_SYS_ADMIN/CAP_SYS_NICE
>
> Reviewed-by: Emil Velikov <emil.l.velikov at gmail.com>
> Reviewed-by: Christian König <christian.koenig at amd.com>
> Signed-off-by: Andres Rodriguez <andresx7 at gmail.com>
I didn't follow all the discussion, so feel free to shut me up if this
has already been discussed, but...
[snip]
> +/* Context priority level */
> +#define AMDGPU_CTX_PRIORITY_NORMAL 0
> +#define AMDGPU_CTX_PRIORITY_LOW 1
> +/* Selecting a priority above NORMAL requires CAP_SYS_ADMIN */
> +#define AMDGPU_CTX_PRIORITY_HIGH 2
> +#define AMDGPU_CTX_PRIORITY_NUM 3
I get that normal priority needs to be 0 for backwards compatibility,
but having LOW between NORMAL and HIGH is still odd. Have you considered
using signed integers as a way to fix that?
(AMDGPU_CTX_PRIORITY_NUM doesn't seem to be used anywhere...)
Cheers,
Nicolai
> +
> struct drm_amdgpu_ctx_in {
> /** AMDGPU_CTX_OP_* */
> __u32 op;
> /** For future use, no flags defined so far */
> __u32 flags;
> __u32 ctx_id;
> - __u32 _pad;
> + __u32 priority;
> };
>
> union drm_amdgpu_ctx_out {
> struct {
> __u32 ctx_id;
> __u32 _pad;
> } alloc;
>
> struct {
> /** For future use, no flags defined so far */
> __u64 flags;
> /** Number of resets caused by this context so far. */
> __u32 hangs;
> /** Reset status since the last call of the ioctl. */
> __u32 reset_status;
> } state;
> };
>
> union drm_amdgpu_ctx {
> struct drm_amdgpu_ctx_in in;
>
--
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.
