Dummyload

Dummyload — Library for submitting GPU workloads

Functions

#define igt_spin_new()
void igt_spin_set_timeout ()
void igt_spin_reset ()
void igt_spin_end ()
void igt_spin_free ()
return READ_ONCE ()
void igt_terminate_spins ()
void igt_unshare_spins ()
#define IGT_CORK()
#define IGT_CORK_HANDLE()
#define IGT_CORK_FENCE()
uint32_t igt_cork_plug ()
void igt_cork_unplug ()

Types and Values

Includes

#include <igt.h>

Description

A lot of igt testcases need some GPU workload to make sure a race window is big enough. Unfortunately having a fixed amount of workload leads to spurious test failures or overly long runtimes on some fast/slow platforms. This library contains functionality to submit GPU workloads that should consume exactly a specific amount of time.

Functions

igt_spin_new()

#define             igt_spin_new(fd, ...)

igt_spin_set_timeout ()

void
igt_spin_set_timeout (igt_spin_t *spin,
                      int64_t ns);

Specify a timeout. This ends the recursive batch associated with spin after the timeout has elapsed.

Parameters

spin

spin state from igt_spin_new()

 

ns

amount of time in nanoseconds the batch continues to execute before finishing.

 

igt_spin_reset ()

void
igt_spin_reset (igt_spin_t *spin);

Reset the state of spin, allowing its reuse.

Parameters

spin

spin state from igt_spin_new()

 

igt_spin_end ()

void
igt_spin_end (igt_spin_t *spin);

End the spinner associated with spin manually.

Parameters

spin

spin state from igt_spin_new()

 

igt_spin_free ()

void
igt_spin_free (int fd,
               igt_spin_t *spin);

This function does the necessary post-processing after starting a spin with igt_spin_new() and then frees it.

Parameters

fd

open i915 drm file descriptor

 

spin

spin state from igt_spin_new()

 

READ_ONCE ()

return
READ_ONCE ();

igt_terminate_spins ()

void
igt_terminate_spins (void);

igt_unshare_spins ()

void
igt_unshare_spins (void);

IGT_CORK()

#define IGT_CORK(name, cork_type) struct igt_cork name = { .type = cork_type, .fd = -1}

IGT_CORK_HANDLE()

#define IGT_CORK_HANDLE(name) IGT_CORK(name, CORK_VGEM_HANDLE)

IGT_CORK_FENCE()

#define IGT_CORK_FENCE(name) IGT_CORK(name, CORK_SYNC_FD)

igt_cork_plug ()

uint32_t
igt_cork_plug (struct igt_cork *cork,
               int fd);

This function provides a mechanism to stall submission. It provides two blocking methods:

VGEM_BO. Imports a vgem bo with a fence attached to it. This bo can be used as a dependency during submission to stall execution until the fence is signaled.

SW_SYNC: Creates a timeline and then a fence on that timeline. The fence can be used as an input fence to a request, the request will be stalled until the fence is signaled.

The parameters required to unblock the execution and to cleanup are stored in the provided cork structure.

Parameters

fd

open drm file descriptor

 

method

method to utilize for corking.

 

cork

structure that will be filled with the state of the cork bo. Note: this has to match the corking method.

 

Returns

Handle of the imported BO / Sw sync fence FD.


igt_cork_unplug ()

void
igt_cork_unplug (struct igt_cork *cork);

This function unblocks the execution by signaling the fence attached to the imported bo and does the necessary post-processing.

NOTE: the handle returned by igt_cork_plug is not closed during this phase.

Parameters

method

method to utilize for corking.

 

cork

cork state from igt_cork_plug()

 

Types and Values

igt_spin_t

typedef struct {
	unsigned int handle;
	timer_t timer;
	struct igt_list_head link;

	uint32_t *condition;
	uint32_t cmd_precondition;

	int out_fence;
	struct drm_i915_gem_exec_object2 obj[2];
#define IGT_SPIN_BATCH   1
	struct drm_i915_gem_execbuffer2 execbuf;
	uint32_t poll_handle;
	uint32_t *poll;
#define SPIN_POLL_START_IDX 0
} igt_spin_t;

struct igt_spin_factory

struct igt_spin_factory {
	uint32_t ctx;
	uint32_t dependency;
	unsigned int engine;
	unsigned int flags;
	int fence;
};

Start a recursive batch on a ring. Immediately returns a igt_spin_t that contains the batch's handle that can be waited upon. The returned structure must be passed to igt_spin_free() for post-processing.

Members

uint32_t ctx;

   

uint32_t dependency;

   

unsigned int engine;

   

unsigned int flags;

   

int fence;

   

IGT_SPIN_FENCE_IN

#define IGT_SPIN_FENCE_IN      (1 << 0)

IGT_SPIN_FENCE_OUT

#define IGT_SPIN_FENCE_OUT     (1 << 1)

IGT_SPIN_POLL_RUN

#define IGT_SPIN_POLL_RUN      (1 << 2)

IGT_SPIN_FAST

#define IGT_SPIN_FAST          (1 << 3)

IGT_SPIN_NO_PREEMPTION

#define IGT_SPIN_NO_PREEMPTION (1 << 4)

IGT_SPIN_INVALID_CS

#define IGT_SPIN_INVALID_CS    (1 << 5)

enum igt_cork_type

Members

CORK_SYNC_FD

   

CORK_VGEM_HANDLE

   

struct igt_cork_vgem

struct igt_cork_vgem {
	int device;
	uint32_t fence;
};

struct igt_cork_sw_sync

struct igt_cork_sw_sync {
	int timeline;
};

struct igt_cork

struct igt_cork {
	enum igt_cork_type type;

	union {
		int fd;

		struct igt_cork_vgem vgem;
		struct igt_cork_sw_sync sw_sync;
	};
};