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Example of app submitting work directly to GPU (bypassing KMD) ?

Kamal_Devanga
Beginner
206 Views

Is there example code for the use case where the user app wants to submit a workload directly to the (gen9) GPU (ie. bypassing the kernel mode driver)? 

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2 Replies
Michael_C_Intel1
Moderator
206 Views

Hello (name withheld),

Can you expand on the goal and define what you mean by 'submit'? 

You may be interested in the c for media project.

You may also be interested in precompiling kernels prior to execution, to something like a SPIR intermediate target... or a target specific executable... See the -x spir toggle here for an example.

Other than that I'm not aware of anyway of bypassing a mechanism to access gen9.

-MichaelC

 

 

Deepika_N_Intel
Employee
206 Views

Hi MichaelC,

I am referring to what I think is described by the patent here. By "submit" I mean enqueue a context to some controller in the GPU from the user application/opencl runtime directly, rather than having the kernel mode driver submit on behalf of the application. I believe there is some way to do so as long as there is some initial agreement set up between the user application and the kernel mode driver. I think it is also alluded to by the code located on this page by the "ContextIndex" and "SubmissionByProxy" values in the following struct: 

//*****************************************************************************
// Struct:  UK_CONTEXT_ID_MAP
// PURPOSE: To represent the context ID structure and execlist/submit queues
//*****************************************************************************
typedef struct UK_CONTEXT_ID_MAP_REC
{
    union
    {
        struct
        {
            ULONG    ContextIndex          : KM_BIT_RANGE(  19,  0);  // NOTE: This can be index in the app context pool in direct submission case or LRCA itself in proxy submission case
            ULONG    SubmissionByProxy     : KM_BIT_RANGE(  20, 20);  // If KMD or other context submitted this context. This means, ContextID is LRCA[31:20]
            ULONG    Reserved              : KM_BIT_RANGE(  22, 21);  // Required by HW
            ULONG    SWCounter             : KM_BIT_RANGE(  28, 23);  // Used for tracking IOMMU group resubmits (or if submit by proxy is true, lower 6 bits QWIndex).
            ULONG    EngineId              : KM_BIT_RANGE(  31, 29);
        };
        ULONG                        ContextIdDword;
    };

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