[Intel-gfx] [PATCH igt 1/3] benchmark/gem_busy: Compare polling with syncobj_wait

[Tvrtko Ursulin]

On 25/09/2017 21:26, Chris Wilson wrote:
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   benchmarks/gem_busy.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 72 insertions(+), 1 deletion(-)
> 
> diff --git a/benchmarks/gem_busy.c b/benchmarks/gem_busy.c
> index f050454b..9649ea02 100644
> --- a/benchmarks/gem_busy.c
> +++ b/benchmarks/gem_busy.c
> @@ -58,6 +58,15 @@
>   #define DMABUF 0x4
>   #define WAIT 0x8
>   #define SYNC 0x10
> +#define SYNCOBJ 0x20
> +
> +#define LOCAL_I915_EXEC_FENCE_ARRAY (1 << 19)
> +struct local_gem_exec_fence {
> +	uint32_t handle;
> +	uint32_t flags;
> +#define LOCAL_EXEC_FENCE_WAIT (1 << 0)
> +#define LOCAL_EXEC_FENCE_SIGNAL (1 << 1)
> +};
>   
>   static void gem_busy(int fd, uint32_t handle)
>   {
> @@ -109,11 +118,54 @@ static int sync_merge(int fd1, int fd2)
>   	return data.fence;
>   }
>   
> +static uint32_t __syncobj_create(int fd)
> +{
> +	struct local_syncobj_create {
> +		uint32_t handle, flags;
> +	} arg;
> +#define LOCAL_IOCTL_SYNCOBJ_CREATE        DRM_IOWR(0xBF, struct local_syncobj_create)
> +
> +	memset(&arg, 0, sizeof(arg));
> +	ioctl(fd, LOCAL_IOCTL_SYNCOBJ_CREATE, &arg);
> +
> +	return arg.handle;
> +}
> +
> +static uint32_t syncobj_create(int fd)
> +{
> +	uint32_t ret;
> +
> +	igt_assert_neq((ret = __syncobj_create(fd)), 0);
> +
> +	return ret;
> +}
> +
> +#define LOCAL_SYNCOBJ_WAIT_FLAGS_WAIT_ALL (1 << 0)
> +#define LOCAL_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT (1 << 1)
> +struct local_syncobj_wait {
> +       __u64 handles;
> +       /* absolute timeout */
> +       __s64 timeout_nsec;
> +       __u32 count_handles;
> +       __u32 flags;
> +       __u32 first_signaled; /* only valid when not waiting all */
> +       __u32 pad;
> +};
> +#define LOCAL_IOCTL_SYNCOBJ_WAIT	DRM_IOWR(0xC3, struct local_syncobj_wait)
> +static int __syncobj_wait(int fd, struct local_syncobj_wait *args)
> +{
> +	int err = 0;
> +	if (drmIoctl(fd, LOCAL_IOCTL_SYNCOBJ_WAIT, args))
> +		err = -errno;
> +	return err;
> +}
> +
>   static int loop(unsigned ring, int reps, int ncpus, unsigned flags)
>   {
>   	struct drm_i915_gem_execbuffer2 execbuf;
>   	struct drm_i915_gem_exec_object2 obj[2];
>   	struct drm_i915_gem_relocation_entry reloc[2];
> +	struct local_gem_exec_fence syncobj;
>   	unsigned engines[16];
>   	unsigned nengine;
>   	uint32_t *batch;
> @@ -126,6 +178,11 @@ static int loop(unsigned ring, int reps, int ncpus, unsigned flags)
>   	fd = drm_open_driver(DRIVER_INTEL);
>   	gen = intel_gen(intel_get_drm_devid(fd));
>   
> +	if (flags & SYNCOBJ) {
> +		syncobj.handle = syncobj_create(fd);
> +		syncobj.flags = LOCAL_EXEC_FENCE_SIGNAL;
> +	}
> +
>   	memset(obj, 0, sizeof(obj));
>   	obj[0].handle = gem_create(fd, 4096);
>   	if (flags & WRITE)
> @@ -144,6 +201,8 @@ static int loop(unsigned ring, int reps, int ncpus, unsigned flags)
>   	execbuf.buffer_count = 2;
>   	execbuf.flags |= LOCAL_I915_EXEC_HANDLE_LUT;
>   	execbuf.flags |= LOCAL_I915_EXEC_NO_RELOC;
> +	if (flags & SYNCOBJ)
> +		execbuf.flags |= LOCAL_I915_EXEC_FENCE_ARRAY;

According to the comment in i915_drm.h, when this is specified, syncobj 
should be also passed in in cliprects_ptr but that's not happening?

Regards,

Tvrtko

>   	if (__gem_execbuf(fd, &execbuf)) {
>   		execbuf.flags = 0;
>   		if (__gem_execbuf(fd, &execbuf))
> @@ -235,6 +294,14 @@ static int loop(unsigned ring, int reps, int ncpus, unsigned flags)
>   					struct pollfd pfd = { .fd = dmabuf, .events = POLLOUT };
>   					for (int inner = 0; inner < 1024; inner++)
>   						poll(&pfd, 1, 0);
> +				} else if (flags & SYNCOBJ) {
> +					struct local_syncobj_wait arg = {
> +						.handles = to_user_pointer(&syncobj.handle),
> +						.count_handles = 1,
> +					};
> +
> +					for (int inner = 0; inner < 1024; inner++)
> +						__syncobj_wait(fd, &arg);
>   				} else if (flags & SYNC) {
>   					struct pollfd pfd = { .fd = fence, .events = POLLOUT };
>   					for (int inner = 0; inner < 1024; inner++)
> @@ -275,7 +342,7 @@ int main(int argc, char **argv)
>   	int ncpus = 1;
>   	int c;
>   
> -	while ((c = getopt (argc, argv, "e:r:dfswWI")) != -1) {
> +	while ((c = getopt (argc, argv, "e:r:dfsSwWI")) != -1) {
>   		switch (c) {
>   		case 'e':
>   			if (strcmp(optarg, "rcs") == 0)
> @@ -314,6 +381,10 @@ int main(int argc, char **argv)
>   			flags |= SYNC;
>   			break;
>   
> +		case 'S':
> +			flags |= SYNCOBJ;
> +			break;
> +
>   		case 'W':
>   			flags |= WRITE;
>   			break;
>