Re: [Intel-gfx] [PATCH] drm/i915/gt: limit lmem allocation size to succeed on SmallBars

[Andrzej Hajda <andrzej.hajda@intel.com>]

On 02.06.2023 11:07, Andi Shyti wrote:
> Hi Andrzej,
> 
> On Thu, Jun 01, 2023 at 04:44:50PM +0200, Andrzej Hajda wrote:
>> In case system is short on mappable memory (256MB on SmallBar) allocation
>> of two 1GB buffers will fail.
>>
>> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8300
>> Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
>> ---
>>   drivers/gpu/drm/i915/gt/selftest_tlb.c | 11 +++++++++--
>>   1 file changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gt/selftest_tlb.c b/drivers/gpu/drm/i915/gt/selftest_tlb.c
>> index 4493c8518e91b2..3bd6b540257b46 100644
>> --- a/drivers/gpu/drm/i915/gt/selftest_tlb.c
>> +++ b/drivers/gpu/drm/i915/gt/selftest_tlb.c
>> @@ -190,11 +190,18 @@ pte_tlbinv(struct intel_context *ce,
>>   
>>   static struct drm_i915_gem_object *create_lmem(struct intel_gt *gt)
>>   {
>> +	struct intel_memory_region *mr = gt->i915->mm.regions[INTEL_REGION_LMEM_0];
>> +	resource_size_t size = SZ_1G;
>> +
>>   	/*
>>   	 * Allocation of largest possible page size allows to test all types
>> -	 * of pages.
>> +	 * of pages. To succeed with both allocations, especially in case of Small
>> +	 * BAR, try to allocate no more than quarter of mappable memory.
>>   	 */
>> -	return i915_gem_object_create_lmem(gt->i915, SZ_1G, I915_BO_ALLOC_CONTIGUOUS);
>> +	if (mr && size > mr->io_size / 4)
>> +		size = mr->io_size / 4;
>> +
>> +	return i915_gem_object_create_lmem(gt->i915, size, I915_BO_ALLOC_CONTIGUOUS);
> 
> makes sense to me.
> 
> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>

Thx, patch merged.

Regards
Andrzej


> 
> Thanks,
> Andi