[PATCH 1/1] drm/amdgpu: rework context priority handling

Christian König christian.koenig at amd.com
Wed Aug 25 12:29:09 UTC 2021


Am 25.08.21 um 14:20 schrieb Lazar, Lijo:
> On 8/25/2021 4:52 PM, Nirmoy Das wrote:
>> To get a hardware queue priority for a context, we are currently
>> mapping AMDGPU_CTX_PRIORITY_* to DRM_SCHED_PRIORITY_* and then
>> to hardware queue priority, which is not the right way to do that
>> as DRM_SCHED_PRIORITY_* is software scheduler's priority and it is
>> independent from a hardware queue priority.
>>
>> Use userspace provided context priority, AMDGPU_CTX_PRIORITY_* to
>> map a context to proper hardware queue priority.
>>
>> Signed-off-by: Nirmoy Das <nirmoy.das at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c   | 127 ++++++++++++++++------
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h   |   8 +-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c |  44 ++------
>>   3 files changed, 105 insertions(+), 74 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>> index e7a010b7ca1f..c88c5c6c54a2 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>> @@ -43,14 +43,61 @@ const unsigned int 
>> amdgpu_ctx_num_entities[AMDGPU_HW_IP_NUM] = {
>>       [AMDGPU_HW_IP_VCN_JPEG]    =    1,
>>   };
>>   +bool amdgpu_ctx_priority_is_valid(int32_t ctx_prio)
>> +{
>> +    switch (ctx_prio) {
>> +    case AMDGPU_CTX_PRIORITY_UNSET:
>> +    case AMDGPU_CTX_PRIORITY_VERY_LOW:
>> +    case AMDGPU_CTX_PRIORITY_LOW:
>> +    case AMDGPU_CTX_PRIORITY_NORMAL:
>> +    case AMDGPU_CTX_PRIORITY_HIGH:
>> +    case AMDGPU_CTX_PRIORITY_VERY_HIGH:
>> +        return true;
>> +    default:
>> +        return false;
>> +    }
>> +}
>> +
>> +static enum drm_sched_priority
>> +amdgpu_ctx_to_drm_sched_prio(int32_t ctx_prio)
>> +{
>> +    switch (ctx_prio) {
>> +    case AMDGPU_CTX_PRIORITY_UNSET:
>> +        return DRM_SCHED_PRIORITY_UNSET;
>> +
>> +    case AMDGPU_CTX_PRIORITY_VERY_LOW:
>> +        return DRM_SCHED_PRIORITY_MIN;
>> +
>> +    case AMDGPU_CTX_PRIORITY_LOW:
>> +        return DRM_SCHED_PRIORITY_MIN;
>> +
>> +    case AMDGPU_CTX_PRIORITY_NORMAL:
>> +        return DRM_SCHED_PRIORITY_NORMAL;
>> +
>> +    case AMDGPU_CTX_PRIORITY_HIGH:
>> +        return DRM_SCHED_PRIORITY_HIGH;
>> +
>> +    case AMDGPU_CTX_PRIORITY_VERY_HIGH:
>> +        return DRM_SCHED_PRIORITY_HIGH;
>> +
>> +    /* This should not happen as we sanitized userspace provided 
>> priority
>> +     * already, WARN if this happens.
>> +     */
>> +    default:
>> +        WARN(1, "Invalid context priority %d\n", ctx_prio);
>> +        return DRM_SCHED_PRIORITY_NORMAL;
>> +    }
>> +
>> +}
>> +
>>   static int amdgpu_ctx_priority_permit(struct drm_file *filp,
>> -                      enum drm_sched_priority priority)
>> +                      int32_t priority)
>>   {
>> -    if (priority < 0 || priority >= DRM_SCHED_PRIORITY_COUNT)
>> +    if (!amdgpu_ctx_priority_is_valid(priority))
>>           return -EINVAL;
>>         /* NORMAL and below are accessible by everyone */
>> -    if (priority <= DRM_SCHED_PRIORITY_NORMAL)
>> +    if (priority <= AMDGPU_CTX_PRIORITY_NORMAL)
>>           return 0;
>>         if (capable(CAP_SYS_NICE))
>> @@ -62,26 +109,35 @@ static int amdgpu_ctx_priority_permit(struct 
>> drm_file *filp,
>>       return -EACCES;
>>   }
>>   -static enum gfx_pipe_priority 
>> amdgpu_ctx_sched_prio_to_compute_prio(enum drm_sched_priority prio)
>> +static enum gfx_pipe_priority 
>> amdgpu_ctx_prio_to_compute_prio(int32_t prio)
>>   {
>>       switch (prio) {
>> -    case DRM_SCHED_PRIORITY_HIGH:
>> -    case DRM_SCHED_PRIORITY_KERNEL:
>> +    case AMDGPU_CTX_PRIORITY_HIGH:
>> +    case AMDGPU_CTX_PRIORITY_VERY_HIGH:
>>           return AMDGPU_GFX_PIPE_PRIO_HIGH;
>>       default:
>>           return AMDGPU_GFX_PIPE_PRIO_NORMAL;
>>       }
>>   }
>>   -static unsigned int amdgpu_ctx_prio_sched_to_hw(struct 
>> amdgpu_device *adev,
>> -                         enum drm_sched_priority prio,
>> -                         u32 hw_ip)
>> +static unsigned int amdgpu_ctx_get_hw_prio(struct amdgpu_ctx *ctx, 
>> u32 hw_ip)
>>   {
>> +    struct amdgpu_device *adev = ctx->adev;
>> +    int32_t ctx_prio;
>>       unsigned int hw_prio;
>>   -    hw_prio = (hw_ip == AMDGPU_HW_IP_COMPUTE) ?
>> -            amdgpu_ctx_sched_prio_to_compute_prio(prio) :
>> -            AMDGPU_RING_PRIO_DEFAULT;
>> +    ctx_prio = (ctx->override_priority == AMDGPU_CTX_PRIORITY_UNSET) ?
>> +            ctx->init_priority : ctx->override_priority;
>> +
>> +    switch (hw_ip) {
>> +    case AMDGPU_HW_IP_COMPUTE:
>> +        hw_prio = amdgpu_ctx_prio_to_compute_prio(ctx_prio);
>> +        break;
>> +    default:
>> +        hw_prio = AMDGPU_RING_PRIO_DEFAULT;
>> +        break;
>> +    }
>> +
>>       hw_ip = array_index_nospec(hw_ip, AMDGPU_HW_IP_NUM);
>>       if (adev->gpu_sched[hw_ip][hw_prio].num_scheds == 0)
>>           hw_prio = AMDGPU_RING_PRIO_DEFAULT;
>> @@ -89,15 +145,17 @@ static unsigned int 
>> amdgpu_ctx_prio_sched_to_hw(struct amdgpu_device *adev,
>>       return hw_prio;
>>   }
>>   +
>>   static int amdgpu_ctx_init_entity(struct amdgpu_ctx *ctx, u32 hw_ip,
>> -                   const u32 ring)
>> +                  const u32 ring)
>>   {
>>       struct amdgpu_device *adev = ctx->adev;
>>       struct amdgpu_ctx_entity *entity;
>>       struct drm_gpu_scheduler **scheds = NULL, *sched = NULL;
>>       unsigned num_scheds = 0;
>> +    int32_t ctx_prio;
>>       unsigned int hw_prio;
>> -    enum drm_sched_priority priority;
>> +    enum drm_sched_priority drm_prio;
>>       int r;
>>         entity = kzalloc(struct_size(entity, fences, amdgpu_sched_jobs),
>> @@ -105,10 +163,11 @@ static int amdgpu_ctx_init_entity(struct 
>> amdgpu_ctx *ctx, u32 hw_ip,
>>       if (!entity)
>>           return  -ENOMEM;
>>   +    ctx_prio = (ctx->override_priority == 
>> AMDGPU_CTX_PRIORITY_UNSET) ?
>> +            ctx->init_priority : ctx->override_priority;
>>       entity->sequence = 1;
>> -    priority = (ctx->override_priority == DRM_SCHED_PRIORITY_UNSET) ?
>> -                ctx->init_priority : ctx->override_priority;
>> -    hw_prio = amdgpu_ctx_prio_sched_to_hw(adev, priority, hw_ip);
>> +    hw_prio = amdgpu_ctx_get_hw_prio(ctx, hw_ip);
>> +    drm_prio = amdgpu_ctx_to_drm_sched_prio(ctx_prio);
>>         hw_ip = array_index_nospec(hw_ip, AMDGPU_HW_IP_NUM);
>>       scheds = adev->gpu_sched[hw_ip][hw_prio].sched;
>> @@ -124,7 +183,7 @@ static int amdgpu_ctx_init_entity(struct 
>> amdgpu_ctx *ctx, u32 hw_ip,
>>           num_scheds = 1;
>>       }
>>   -    r = drm_sched_entity_init(&entity->entity, priority, scheds, 
>> num_scheds,
>> +    r = drm_sched_entity_init(&entity->entity, drm_prio, scheds, 
>> num_scheds,
>>                     &ctx->guilty);
>>       if (r)
>>           goto error_free_entity;
>> @@ -139,7 +198,7 @@ static int amdgpu_ctx_init_entity(struct 
>> amdgpu_ctx *ctx, u32 hw_ip,
>>   }
>>     static int amdgpu_ctx_init(struct amdgpu_device *adev,
>> -               enum drm_sched_priority priority,
>> +               int32_t priority,
>>                  struct drm_file *filp,
>>                  struct amdgpu_ctx *ctx)
>>   {
>> @@ -161,7 +220,7 @@ static int amdgpu_ctx_init(struct amdgpu_device 
>> *adev,
>>       ctx->reset_counter_query = ctx->reset_counter;
>>       ctx->vram_lost_counter = atomic_read(&adev->vram_lost_counter);
>>       ctx->init_priority = priority;
>> -    ctx->override_priority = DRM_SCHED_PRIORITY_UNSET;
>> +    ctx->override_priority = AMDGPU_CTX_PRIORITY_UNSET;
>>         return 0;
>>   }
>> @@ -234,7 +293,7 @@ int amdgpu_ctx_get_entity(struct amdgpu_ctx *ctx, 
>> u32 hw_ip, u32 instance,
>>   static int amdgpu_ctx_alloc(struct amdgpu_device *adev,
>>                   struct amdgpu_fpriv *fpriv,
>>                   struct drm_file *filp,
>> -                enum drm_sched_priority priority,
>> +                int32_t priority,
>>                   uint32_t *id)
>>   {
>>       struct amdgpu_ctx_mgr *mgr = &fpriv->ctx_mgr;
>> @@ -397,19 +456,19 @@ int amdgpu_ctx_ioctl(struct drm_device *dev, 
>> void *data,
>>   {
>>       int r;
>>       uint32_t id;
>> -    enum drm_sched_priority priority;
>> +    int32_t priority;
>>         union drm_amdgpu_ctx *args = data;
>>       struct amdgpu_device *adev = drm_to_adev(dev);
>>       struct amdgpu_fpriv *fpriv = filp->driver_priv;
>>         id = args->in.ctx_id;
>> -    r = amdgpu_to_sched_priority(args->in.priority, &priority);
>> +    priority = args->in.priority;
>>         /* For backwards compatibility reasons, we need to accept
>>        * ioctls with garbage in the priority field */
>> -    if (r == -EINVAL)
>> -        priority = DRM_SCHED_PRIORITY_NORMAL;
>> +    if (!amdgpu_ctx_priority_is_valid(priority))
>> +        priority = AMDGPU_CTX_PRIORITY_NORMAL;
>>         switch (args->in.op) {
>>       case AMDGPU_CTX_OP_ALLOC_CTX:
>> @@ -515,9 +574,9 @@ struct dma_fence *amdgpu_ctx_get_fence(struct 
>> amdgpu_ctx *ctx,
>>   }
>>     static void amdgpu_ctx_set_entity_priority(struct amdgpu_ctx *ctx,
>> -                        struct amdgpu_ctx_entity *aentity,
>> -                        int hw_ip,
>> -                        enum drm_sched_priority priority)
>> +                       struct amdgpu_ctx_entity *aentity,
>> +                       int hw_ip,
>> +                       int32_t priority)
>>   {
>>       struct amdgpu_device *adev = ctx->adev;
>>       unsigned int hw_prio;
>> @@ -525,12 +584,12 @@ static void 
>> amdgpu_ctx_set_entity_priority(struct amdgpu_ctx *ctx,
>>       unsigned num_scheds;
>>         /* set sw priority */
>> -    drm_sched_entity_set_priority(&aentity->entity, priority);
>> +    drm_sched_entity_set_priority(&aentity->entity,
>> +                      amdgpu_ctx_to_drm_sched_prio(priority));
>>         /* set hw priority */
>>       if (hw_ip == AMDGPU_HW_IP_COMPUTE) {
>> -        hw_prio = amdgpu_ctx_prio_sched_to_hw(adev, priority,
>> -                              AMDGPU_HW_IP_COMPUTE);
>> +        hw_prio = amdgpu_ctx_get_hw_prio(ctx, hw_ip);
>>           hw_prio = array_index_nospec(hw_prio, AMDGPU_RING_PRIO_MAX);
>
> Not related to this patch, but this kind of logic may break some day. 
> There is a HWIP specific priority and there is another RING_PRIO which 
> is unmapped to HWIP priority Ex: when a new priority is added for VCN 
> which is higher than any of the existing priorities.

Yes, that's something I've noticed as well.

Either we should leave the exact mapping to the engine or have a global 
definition of possible hw priorities (the later is preferable I think).

Christian.

>
> Thanks,
> Lijo
>
>>           scheds = adev->gpu_sched[hw_ip][hw_prio].sched;
>>           num_scheds = adev->gpu_sched[hw_ip][hw_prio].num_scheds;
>> @@ -540,14 +599,14 @@ static void 
>> amdgpu_ctx_set_entity_priority(struct amdgpu_ctx *ctx,
>>   }
>>     void amdgpu_ctx_priority_override(struct amdgpu_ctx *ctx,
>> -                  enum drm_sched_priority priority)
>> +                  int32_t priority)
>>   {
>> -    enum drm_sched_priority ctx_prio;
>> +    int32_t ctx_prio;
>>       unsigned i, j;
>>         ctx->override_priority = priority;
>>   -    ctx_prio = (ctx->override_priority == DRM_SCHED_PRIORITY_UNSET) ?
>> +    ctx_prio = (ctx->override_priority == AMDGPU_CTX_PRIORITY_UNSET) ?
>>               ctx->init_priority : ctx->override_priority;
>>       for (i = 0; i < AMDGPU_HW_IP_NUM; ++i) {
>>           for (j = 0; j < amdgpu_ctx_num_entities[i]; ++j) {
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
>> index 14db16bc3322..a44b8b8ed39c 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
>> @@ -47,8 +47,8 @@ struct amdgpu_ctx {
>>       spinlock_t            ring_lock;
>>       struct amdgpu_ctx_entity 
>> *entities[AMDGPU_HW_IP_NUM][AMDGPU_MAX_ENTITY_NUM];
>>       bool                preamble_presented;
>> -    enum drm_sched_priority        init_priority;
>> -    enum drm_sched_priority        override_priority;
>> +    int32_t                init_priority;
>> +    int32_t                override_priority;
>>       struct mutex            lock;
>>       atomic_t            guilty;
>>       unsigned long            ras_counter_ce;
>> @@ -75,8 +75,8 @@ void amdgpu_ctx_add_fence(struct amdgpu_ctx *ctx,
>>   struct dma_fence *amdgpu_ctx_get_fence(struct amdgpu_ctx *ctx,
>>                          struct drm_sched_entity *entity,
>>                          uint64_t seq);
>> -void amdgpu_ctx_priority_override(struct amdgpu_ctx *ctx,
>> -                  enum drm_sched_priority priority);
>> +bool amdgpu_ctx_priority_is_valid(int32_t ctx_prio);
>> +void amdgpu_ctx_priority_override(struct amdgpu_ctx *ctx, int32_t 
>> ctx_prio);
>>     int amdgpu_ctx_ioctl(struct drm_device *dev, void *data,
>>                struct drm_file *filp);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
>> index b7d861ed5284..e9b45089a28a 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c
>> @@ -32,37 +32,9 @@
>>   #include "amdgpu_sched.h"
>>   #include "amdgpu_vm.h"
>>   -int amdgpu_to_sched_priority(int amdgpu_priority,
>> -                 enum drm_sched_priority *prio)
>> -{
>> -    switch (amdgpu_priority) {
>> -    case AMDGPU_CTX_PRIORITY_VERY_HIGH:
>> -        *prio = DRM_SCHED_PRIORITY_HIGH;
>> -        break;
>> -    case AMDGPU_CTX_PRIORITY_HIGH:
>> -        *prio = DRM_SCHED_PRIORITY_HIGH;
>> -        break;
>> -    case AMDGPU_CTX_PRIORITY_NORMAL:
>> -        *prio = DRM_SCHED_PRIORITY_NORMAL;
>> -        break;
>> -    case AMDGPU_CTX_PRIORITY_LOW:
>> -    case AMDGPU_CTX_PRIORITY_VERY_LOW:
>> -        *prio = DRM_SCHED_PRIORITY_MIN;
>> -        break;
>> -    case AMDGPU_CTX_PRIORITY_UNSET:
>> -        *prio = DRM_SCHED_PRIORITY_UNSET;
>> -        break;
>> -    default:
>> -        WARN(1, "Invalid context priority %d\n", amdgpu_priority);
>> -        return -EINVAL;
>> -    }
>> -
>> -    return 0;
>> -}
>> -
>>   static int amdgpu_sched_process_priority_override(struct 
>> amdgpu_device *adev,
>>                             int fd,
>> -                          enum drm_sched_priority priority)
>> +                          int32_t priority)
>>   {
>>       struct fd f = fdget(fd);
>>       struct amdgpu_fpriv *fpriv;
>> @@ -89,7 +61,7 @@ static int 
>> amdgpu_sched_process_priority_override(struct amdgpu_device *adev,
>>   static int amdgpu_sched_context_priority_override(struct 
>> amdgpu_device *adev,
>>                             int fd,
>>                             unsigned ctx_id,
>> -                          enum drm_sched_priority priority)
>> +                          int32_t priority)
>>   {
>>       struct fd f = fdget(fd);
>>       struct amdgpu_fpriv *fpriv;
>> @@ -124,7 +96,6 @@ int amdgpu_sched_ioctl(struct drm_device *dev, 
>> void *data,
>>   {
>>       union drm_amdgpu_sched *args = data;
>>       struct amdgpu_device *adev = drm_to_adev(dev);
>> -    enum drm_sched_priority priority;
>>       int r;
>>         /* First check the op, then the op's argument.
>> @@ -138,21 +109,22 @@ int amdgpu_sched_ioctl(struct drm_device *dev, 
>> void *data,
>>           return -EINVAL;
>>       }
>>   -    r = amdgpu_to_sched_priority(args->in.priority, &priority);
>> -    if (r)
>> -        return r;
>> +    if (!amdgpu_ctx_priority_is_valid(args->in.priority)) {
>> +        WARN(1, "Invalid context priority %d\n", args->in.priority);
>> +        return -EINVAL;
>> +    }
>>         switch (args->in.op) {
>>       case AMDGPU_SCHED_OP_PROCESS_PRIORITY_OVERRIDE:
>>           r = amdgpu_sched_process_priority_override(adev,
>>                                  args->in.fd,
>> -                               priority);
>> +                               args->in.priority);
>>           break;
>>       case AMDGPU_SCHED_OP_CONTEXT_PRIORITY_OVERRIDE:
>>           r = amdgpu_sched_context_priority_override(adev,
>>                                  args->in.fd,
>>                                  args->in.ctx_id,
>> -                               priority);
>> +                               args->in.priority);
>>           break;
>>       default:
>>           /* Impossible.
>>



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