[Intel-gfx] [PATCH i-g-t v2] tests/gem_lmem_swapping: add some coverage for big objects

[Das, Nirmoy]

LGTM Reviewed-by: Nirmoy Das <nirmoy.das at intel.com>

On 8/9/2022 12:26 PM, Matthew Auld wrote:
> Everything we are testing here unfortunately fits within one packet (8M)
> which means we have zero coverage when we need to split the copy over
> multiple packets (including the aux CCS state).
>
> v2:
>   - Add some coverage for 2G objects, just to see if something blows up
>     with overflowing int. (Ram)
>   - Just make TEST_RANDOM use bigger sizes to ensure we get coverage of
>     objects that require splitting the copy into multiple packets.
>
> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> Cc: Ramalingam C <ramalingam.c at intel.com>
> ---
>   tests/i915/gem_lmem_swapping.c | 18 ++++++++++++++++--
>   1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/tests/i915/gem_lmem_swapping.c b/tests/i915/gem_lmem_swapping.c
> index 1a4f4ca5..cccdb319 100644
> --- a/tests/i915/gem_lmem_swapping.c
> +++ b/tests/i915/gem_lmem_swapping.c
> @@ -63,6 +63,7 @@ struct params {
>   #define TEST_ENGINES	(1 << 4)
>   #define TEST_MULTI	(1 << 5)
>   #define TEST_CCS	(1 << 6)
> +#define TEST_MASSIVE	(1 << 7)
>   	unsigned int flags;
>   	unsigned int seed;
>   	bool oom_test;
> @@ -477,8 +478,8 @@ static void fill_params(int i915, struct params *params,
>   {
>   	const int swap_mb = /* For lmem, swap is total of smem + swap. */
>   		igt_get_total_ram_mb() + igt_get_total_swap_mb();
> -	const unsigned int size = 1 << 20;
>   	const int max_swap_pct = 75;
> +	unsigned int size;
>   	/*
>   	 * In random mode, add 85% hard limit to use system memory.
>   	 * noticed that 88.8% can trigger OOM on some system.
> @@ -487,12 +488,23 @@ static void fill_params(int i915, struct params *params,
>   	int spill_mb;
>   	uint32_t handle;
>   
> +	size = 1 << 20;
> +	if (flags & TEST_MASSIVE)
> +		size = 1u << 31;
> +
>   	if (flags & TEST_RANDOM) {
>   		params->size.min = 4096;
>   		handle = create_bo(i915, &params->size.min, &region->region,
>   				   do_oom_test);
>   		gem_close(i915, handle);
> -		params->size.max = 2 * size + params->size.min;
> +		/*
> +		 * Big enough to ensure we need to split the copy (both the
> +		 * actual pages and aux CCS state) into multiple packets. Also
> +		 * larger enough to ensure we get a mix of 64K and 2M GTT pages
> +		 * (1G GTT pages are still missing from the kernel).
> +		 */
> +		params->size.max = (1ul << 24) + size + params->size.min;
> +		size = params->size.max;
>   	} else {
>   		params->size.min = size;
>   		params->size.max = size;
> @@ -733,6 +745,8 @@ igt_main_args("", long_options, help_str, opt_handler, NULL)
>   		unsigned int flags;
>   	} *test, tests[] = {
>   		{ "basic", 0 },
> +		{ "massive",  TEST_MASSIVE }, /* check for (int) overflows */
> +		{ "massive-random",  TEST_RANDOM | TEST_MASSIVE },
>   		{ "random", TEST_RANDOM },
>   		{ "random-engines", TEST_RANDOM | TEST_ENGINES },
>   		{ "heavy-random", TEST_RANDOM | TEST_HEAVY },