[Intel-gfx] [PATCH i-g-t 2/4] gem_create: Test huge object creation as a basic test

[Tvrtko Ursulin]

On 30/03/2017 18:22, Chris Wilson wrote:
> On Thu, Mar 30, 2017 at 05:58:07PM +0100, Tvrtko Ursulin wrote:
>> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>
>> It is hard to imagine a more basic test than this one.
>>
>> Also removed the skip on simulation since I don't know why
>> would that be needed here.
>>
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>> ---
>>  tests/gem_create.c | 10 ++++++----
>>  1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/tests/gem_create.c b/tests/gem_create.c
>> index de7b82094545..f687b7b40be4 100644
>> --- a/tests/gem_create.c
>> +++ b/tests/gem_create.c
>> @@ -44,6 +44,7 @@
>>  #include <sys/stat.h>
>>  #include <sys/time.h>
>>  #include <getopt.h>
>> +#include <limits.h>
>>
>>  #include <drm.h>
>>
>> @@ -95,10 +96,13 @@ static void invalid_flag_test(int fd)
>>
>>  static void invalid_size_test(int fd)
>>  {
>> -	int handle;
>> +	uint32_t handle;
>>
>>  	handle = __gem_create(fd, 0);
>>  	igt_assert(!handle);
>> +
>> +	handle = __gem_create(fd, INT_MAX * 4096UL + 1);
>
> Why is that an invalid size? Invalid huge in terms of API might arguably
> be 1<<virtual_bits + 1, but otherwise our only limitation is that it
> has to be >0 and page aligned.

Because of the comment above the WARN I am removing in "drm/i915: Remove 
user triggerable WARN from i915_gem_object_create". We cannot support 
larger ones with the combination of sg_table data types and how we use 
them (unsigned int nents).

> /* Only multiples of page size (4096) are allowed. Check all likely
>  * misalignments from pot boundaries to check validity and possibility
>  * of incorrect overflow.
>  */
>  for (int order = 0; order < 64; order++) {
>  	uint64_t size = (uint64_t)1 << order;
> 	igt_assert(!__gem_create(fd, size - 1));
> 	igt_assert(!__gem_create(fd, size + 1));
> 	if (order < 12)
> 		igt_assert(!__gem_create(fd, size + 1));
> }
>
> Still enshrines knowlege of PAGE_SIZE into the ABI. Meh.

We round up for the user transparently which I am actually making the 
other subtest in this file test in a later patch.

Regards,

Tvrtko