[igt-dev] [PATCH i-g-t] tests/i915/gem_softpin: Exercise single offset eviction on all engines

[Kamil Konieczny]

Hi Zbigniew,

On 2022-04-27 at 20:42:04 +0200, Zbigniew Kempczyński wrote:
> Verify that eviction works when all engines try to use same offset for
> different handles. It replaces allocator-evict-all-engines test because
> it is simpler.
> 
> v2: addressing review comments (Kamil)
> v3: simplifying subtest (Chris)
> 
> Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>
> Cc: Kamil Konieczny <kamil.konieczny at linux.intel.com>
> Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> ---
>  tests/i915/gem_softpin.c | 76 ++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 74 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/i915/gem_softpin.c b/tests/i915/gem_softpin.c
> index 448b4c4b9e..7dae2a6c44 100644
> --- a/tests/i915/gem_softpin.c
> +++ b/tests/i915/gem_softpin.c
> @@ -1073,6 +1073,77 @@ static void test_allocator_evict(int fd, const intel_ctx_t *ctx,
>  	igt_assert_eq(intel_detect_and_clear_missed_interrupts(fd), 0);
>  }
>  
> +#define MINIMAL_OFFSET 0x200000
> +static void single_offset_submit(int fd, struct drm_i915_gem_execbuffer2 *eb,
> +				 struct batch *batches, unsigned int count)
> +{
> +	struct drm_i915_gem_exec_object2 obj = {
> +		.offset = max_t(uint64_t, gem_detect_safe_start_offset(fd), MINIMAL_OFFSET),

imho this should be a parameter to this function, so it will be
calculated once but you can leave it here, your choice.

> +		.flags = EXEC_OBJECT_PINNED,
> +	};
> +
> +	eb->buffers_ptr = to_user_pointer(&obj);
> +
> +	for (unsigned int i = 0; i < count; i++) {
> +		obj.handle = batches[i].handle;
> +		gem_execbuf(fd, eb);
> +	}
> +}
> +
> +static void evict_single_offset(int fd, const intel_ctx_t *ctx, int timeout)
> +{
> +	struct drm_i915_gem_execbuffer2 execbuf;
> +	struct intel_execution_engine2 *e;
> +	unsigned int engines[I915_EXEC_RING_MASK + 1];
> +	struct batch *batches;
> +	unsigned int nengine;
> +	unsigned int count;
> +	uint64_t size, batch_size = BATCH_SIZE;
> +
> +	nengine = 0;
> +	for_each_ctx_engine(fd, ctx, e) {
> +		engines[nengine++] = e->flags;
> +	}
> +	igt_require(nengine);
> +
> +	size = gem_aperture_size(fd);
> +	if (size > 1ull<<32) /* Limit to 4GiB as we do not use allow-48b */
> +		size = 1ull << 32;
> +	igt_require(size < (1ull<<32) * BATCH_SIZE);
> +
> +	count = size / BATCH_SIZE + 1;
> +	igt_debug("Using %'d batches to fill %'llu aperture on %d engines\n",
> +		  count, (long long)size, nengine);

Please add here print for timeout used and also change printing
size to MB.

> +
> +	intel_require_memory(count, BATCH_SIZE, CHECK_RAM);
> +	intel_detect_and_clear_missed_interrupts(fd);
> +
> +	memset(&execbuf, 0, sizeof(execbuf));
> +	execbuf.buffer_count = 1;
> +	execbuf.rsvd1 = ctx->id;
> +
> +	batches = calloc(count, sizeof(*batches));
> +	igt_assert(batches);
> +	for (unsigned int i = 0; i < count; i++)
> +		batches[i].handle = batch_create(fd, &batch_size);
> +
> +	/* Flush all memory before we start the timer */
> +	single_offset_submit(fd, &execbuf, batches, count);
> +
> +	igt_fork(child, nengine) {
> +		execbuf.flags |= engines[child];
> +		igt_until_timeout(timeout)
> +			single_offset_submit(fd, &execbuf, batches, count);
> +	}
> +	igt_waitchildren();
> +
> +	for (unsigned int i = 0; i < count; i++)
> +		gem_close(fd, batches[i].handle);
> +	free(batches);
> +
> +	igt_assert_eq(intel_detect_and_clear_missed_interrupts(fd), 0);
> +}
> +
>  static void make_batch(int i915, uint32_t handle, uint64_t size)
>  {
>  	uint32_t *bb = gem_mmap__device_coherent(i915, handle, 0, size, PROT_WRITE);
> @@ -1213,8 +1284,9 @@ igt_main
>  		test_each_engine("allocator-evict", fd, ctx, e)
>  			test_allocator_evict(fd, ctx, e->flags, 20);
>  
> -		igt_subtest("allocator-evict-all-engines")
> -			test_allocator_evict(fd, ctx, ALL_ENGINES, 20);
> +		igt_describe("Use same offset for all engines and for different handles");
> +		igt_subtest("evict-single-offset")
> +			evict_single_offset(fd, ctx, 20);

You are not using allocator here, so maybe move this down after
evict-hog sibtest ?

With that small changes you can add my r-b tag.

Regards,
Kamil
>  	}
>  
>  	igt_describe("Check start offset and alignment detection");
> -- 
> 2.32.0
>