[igt-dev] [PATCH i-g-t 1/2] tests/i915/api_intel_allocator: Exercise allocator in multiprocess mode

[Zbigniew Kempczyński]

On Thu, Jun 17, 2021 at 09:16:42AM +0200, Andrzej Turko wrote:
> Test creation and usage of allocators in multiprocess mode
> for contexts shared with the parent process as well as
> private for the child.
> 
> This new test discovers a bug in the allocator implementation:
> allocator is not correctly initialized if it is opened by
> a child process using its private file descriptor.
> 
> Signed-off-by: Andrzej Turko <andrzej.turko at linux.intel.com>
> Cc: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>

This exposes some allocator thread weak point - asserting and blocking ipc.
I'm enquing work to improve this. But test is ok:

Reviewed-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>

--
Zbigniew


> ---
>  tests/i915/api_intel_allocator.c | 40 ++++++++++++++++++++++++++++++++
>  1 file changed, 40 insertions(+)
> 
> diff --git a/tests/i915/api_intel_allocator.c b/tests/i915/api_intel_allocator.c
> index ea4ba8bb1..fdfbdba82 100644
> --- a/tests/i915/api_intel_allocator.c
> +++ b/tests/i915/api_intel_allocator.c
> @@ -621,6 +621,43 @@ static void execbuf_with_allocator(int fd)
>  	igt_assert(intel_allocator_close(ahnd) == true);
>  }
>  
> +static void fork_reopen_allocator(int fd, uint8_t type)
> +{
> +	uint64_t p_ahnd, sh_ahnd, fd_ahnd, ctx_ahnd;
> +	uint64_t offset;
> +
> +	intel_allocator_multiprocess_start();
> +
> +	p_ahnd = intel_allocator_open(fd, 0, type);
> +	offset = intel_allocator_alloc(p_ahnd, 1, 123, 0);
> +	if (type == INTEL_ALLOCATOR_SIMPLE)
> +		igt_assert(intel_allocator_is_allocated(p_ahnd, 1, 123, offset));
> +
> +	igt_fork(child, 1) {
> +		sh_ahnd = intel_allocator_open(fd, 0, type);
> +		if (type == INTEL_ALLOCATOR_SIMPLE)
> +			igt_assert(intel_allocator_is_allocated(sh_ahnd, 1, 123, offset));
> +
> +		ctx_ahnd = intel_allocator_open(fd, 1, type);
> +		igt_assert(!intel_allocator_is_allocated(ctx_ahnd, 1, 123, offset));
> +		intel_allocator_alloc(ctx_ahnd, 2, 123, 0);
> +
> +		fd = gem_reopen_driver(fd);
> +		fd_ahnd = intel_allocator_open(fd, 0, type);
> +		igt_assert(!intel_allocator_is_allocated(fd_ahnd, 1, 123, offset));
> +		intel_allocator_alloc(fd_ahnd, 2, 123, 0);
> +
> +		intel_allocator_close(sh_ahnd);
> +		intel_allocator_close(ctx_ahnd);
> +		intel_allocator_close(fd_ahnd);
> +	}
> +
> +	igt_waitchildren();
> +	intel_allocator_close(p_ahnd);
> +
> +	intel_allocator_multiprocess_stop();
> +}
> +
>  struct allocators {
>  	const char *name;
>  	uint8_t type;
> @@ -672,6 +709,9 @@ igt_main
>  				igt_dynamic("reserve")
>  					reserve(fd, a->type);
>  			}
> +
> +			igt_dynamic("fork-reopen-allocator")
> +					fork_reopen_allocator(fd, a->type);
>  		}
>  	}
>  
> -- 
> 2.25.1
>