Re: [Intel-gfx] [PATCH 4/5] drm/i915/ttm: Use TTM for system memory

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

On 6/3/21 11:48 AM, Matthew Auld wrote:
> On Wed, 2 Jun 2021 at 18:08, Thomas Hellström
> <thomas.hellstrom@linux.intel.com> wrote:
>> For discrete, use TTM for both cached and WC system memory. That means
>> we currently rely on the TTM memory accounting / shrinker. For cached
>> system memory we should consider remaining shmem-backed, which can be
>> implemented from our ttm_tt_populate calback. We can then also reuse our
>> own very elaborate shrinker for that memory.
>>
>> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
>> ---
>>   drivers/gpu/drm/i915/gem/i915_gem_ttm.c    | 22 ++++++++++++++++++++++
>>   drivers/gpu/drm/i915/i915_drv.h            |  3 ---
>>   drivers/gpu/drm/i915/intel_memory_region.c |  7 ++++++-
>>   drivers/gpu/drm/i915/intel_memory_region.h |  8 ++++++++
>>   4 files changed, 36 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> index 8e1c01168c6d..42e89bf43708 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> @@ -755,3 +755,25 @@ int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
>>          /* i915 wants -ENXIO when out of memory region space. */
>>          return (ret == -ENOSPC) ? -ENXIO : ret;
>>   }
>> +
>> +static const struct intel_memory_region_ops ttm_system_region_ops = {
>> +       .init_object = __i915_gem_ttm_object_init,
>> +};
>> +
>> +struct intel_memory_region *
>> +i915_gem_ttm_system_setup(struct drm_i915_private *i915,
>> +                         u16 type, u16 instance)
>> +{
>> +       struct intel_memory_region *mr;
>> +
>> +       mr = intel_memory_region_create(i915, 0,
>> +                                       totalram_pages() << PAGE_SHIFT,
>> +                                       PAGE_SIZE, 0,
>> +                                       type, instance,
>> +                                       &ttm_system_region_ops);
>> +       if (IS_ERR_OR_NULL(mr))
> region_create can't return NULL.
OK, will fix.