[Intel-gfx] [PATCH v5 09/13] drm/i915/ttm: add tt shmem backend
Matthew Auld
matthew.auld at intel.com
Tue Oct 5 17:07:07 UTC 2021
On 05/10/2021 15:23, Zeng, Oak wrote:
>
>
> Regards,
> Oak
>
>> -----Original Message-----
>> From: Thomas Hellström <thomas.hellstrom at linux.intel.com>
>> Sent: October 5, 2021 9:48 AM
>> To: Zeng, Oak <oak.zeng at intel.com>; Auld, Matthew
>> <matthew.auld at intel.com>; intel-gfx at lists.freedesktop.org
>> Cc: dri-devel at lists.freedesktop.org; Christian König
>> <christian.koenig at amd.com>
>> Subject: Re: [Intel-gfx] [PATCH v5 09/13] drm/i915/ttm: add tt shmem
>> backend
>>
>>
>> On 10/5/21 04:05, Zeng, Oak wrote:
>>> Hi Matthew/Thomas,
>>>
>>> See one question inline
>>>
>>> Regards,
>>> Oak
>>>
>>> -----Original Message-----
>>> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of
>> Matthew Auld
>>> Sent: September 27, 2021 7:41 AM
>>> To: intel-gfx at lists.freedesktop.org
>>> Cc: dri-devel at lists.freedesktop.org; Thomas Hellström
>> <thomas.hellstrom at linux.intel.com>; Christian König
>> <christian.koenig at amd.com>
>>> Subject: [Intel-gfx] [PATCH v5 09/13] drm/i915/ttm: add tt shmem backend
>>>
>>> For cached objects we can allocate our pages directly in shmem. This should
>> make it possible(in a later patch) to utilise the existing i915-gem shrinker code
>> for such objects. For now this is still disabled.
>>>
>>> v2(Thomas):
>>> - Add optional try_to_writeback hook for objects. Importantly we need
>>> to check if the object is even still shrinkable; in between us
>>> dropping the shrinker LRU lock and acquiring the object lock it could for
>>> example have been moved. Also we need to differentiate between
>>> "lazy" shrinking and the immediate writeback mode. Also later we need
>> to
>>> handle objects which don't even have mm.pages, so bundling this into
>>> put_pages() would require somehow handling that edge case, hence
>>> just letting the ttm backend handle everything in try_to_writeback
>>> doesn't seem too bad.
>>> v3(Thomas):
>>> - Likely a bad idea to touch the object from the unpopulate hook,
>>> since it's not possible to hold a reference, without also creating
>>> circular dependency, so likely this is too fragile. For now just
>>> ensure we at least mark the pages as dirty/accessed when called from the
>>> shrinker on WILLNEED objects.
>>> - s/try_to_writeback/shrinker_release_pages, since this can do more
>>> than just writeback.
>>> - Get rid of do_backup boolean and just set the SWAPPED flag prior to
>>> calling unpopulate.
>>> - Keep shmem_tt as lowest priority for the TTM LRU bo_swapout walk,
>> since
>>> these just get skipped anyway. We can try to come up with something
>>> better later.
>>>
>>> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
>>> Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
>>> Cc: Christian König <christian.koenig at amd.com>
>>> ---
>>> drivers/gpu/drm/i915/gem/i915_gem_object.h | 8 +
>>> .../gpu/drm/i915/gem/i915_gem_object_types.h | 2 +
>>> drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 14 +-
>>> drivers/gpu/drm/i915/gem/i915_gem_shrinker.c | 17 +-
>>> drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 240 ++++++++++++++++-
>> -
>>> 5 files changed, 245 insertions(+), 36 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h
>> b/drivers/gpu/drm/i915/gem/i915_gem_object.h
>>> index 3043fcbd31bd..1c9a1d8d3434 100644
>>> --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
>>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
>>> @@ -601,6 +601,14 @@ int i915_gem_object_wait_migration(struct
>> drm_i915_gem_object *obj, bool
>> i915_gem_object_placement_possible(struct drm_i915_gem_object *obj,
>>> enum intel_memory_type type);
>>>
>>> +struct sg_table *shmem_alloc_st(struct drm_i915_private *i915,
>>> + size_t size, struct intel_memory_region *mr,
>>> + struct address_space *mapping,
>>> + unsigned int max_segment);
>>> +void shmem_free_st(struct sg_table *st, struct address_space *mapping,
>>> + bool dirty, bool backup);
>>> +void __shmem_writeback(size_t size, struct address_space *mapping);
>>> +
>>> #ifdef CONFIG_MMU_NOTIFIER
>>> static inline bool
>>> i915_gem_object_is_userptr(struct drm_i915_gem_object *obj) diff --git
>> a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
>> b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
>>> index fa2ba9e2a4d0..f0fb17be2f7a 100644
>>> --- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
>>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
>>> @@ -56,6 +56,8 @@ struct drm_i915_gem_object_ops {
>>> struct sg_table *pages);
>>> void (*truncate)(struct drm_i915_gem_object *obj);
>>> void (*writeback)(struct drm_i915_gem_object *obj);
>>> + int (*shrinker_release_pages)(struct drm_i915_gem_object *obj,
>>> + bool should_writeback);
>>>
>>> int (*pread)(struct drm_i915_gem_object *obj,
>>> const struct drm_i915_gem_pread *arg); diff --git
>> a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
>> b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
>>> index 36b711ae9e28..19e55cc29a15 100644
>>> --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
>>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
>>> @@ -25,8 +25,8 @@ static void check_release_pagevec(struct pagevec
>> *pvec)
>>> cond_resched();
>>> }
>>>
>>> -static void shmem_free_st(struct sg_table *st, struct address_space
>> *mapping,
>>> - bool dirty, bool backup)
>>> +void shmem_free_st(struct sg_table *st, struct address_space *mapping,
>>> + bool dirty, bool backup)
>>> {
>>> struct sgt_iter sgt_iter;
>>> struct pagevec pvec;
>>> @@ -52,10 +52,10 @@ static void shmem_free_st(struct sg_table *st, struct
>> address_space *mapping,
>>> kfree(st);
>>> }
>>>
>>> -static struct sg_table *shmem_alloc_st(struct drm_i915_private *i915,
>>> - size_t size, struct intel_memory_region
>> *mr,
>>> - struct address_space *mapping,
>>> - unsigned int max_segment)
>>> +struct sg_table *shmem_alloc_st(struct drm_i915_private *i915,
>>> + size_t size, struct intel_memory_region *mr,
>>> + struct address_space *mapping,
>>> + unsigned int max_segment)
>>> {
>>> const unsigned long page_count = size / PAGE_SIZE;
>>> unsigned long i;
>>> @@ -300,7 +300,7 @@ shmem_truncate(struct drm_i915_gem_object *obj)
>>> obj->mm.pages = ERR_PTR(-EFAULT);
>>> }
>>>
>>> -static void __shmem_writeback(size_t size, struct address_space
>> *mapping)
>>> +void __shmem_writeback(size_t size, struct address_space *mapping)
>>> {
>>> struct writeback_control wbc = {
>>> .sync_mode = WB_SYNC_NONE,
>>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
>> b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
>>> index e382b7f2353b..cc80bd23d323 100644
>>> --- a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
>>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
>>> @@ -56,19 +56,24 @@ static bool unsafe_drop_pages(struct
>> drm_i915_gem_object *obj,
>>> return false;
>>> }
>>>
>>> -static void try_to_writeback(struct drm_i915_gem_object *obj,
>>> - unsigned int flags)
>>> +static int try_to_writeback(struct drm_i915_gem_object *obj, unsigned
>>> +int flags)
>>> {
>>> + if (obj->ops->shrinker_release_pages)
>>> + return obj->ops->shrinker_release_pages(obj,
>>> + flags &
>> I915_SHRINK_WRITEBACK);
>>> +
>>> switch (obj->mm.madv) {
>>> case I915_MADV_DONTNEED:
>>> i915_gem_object_truncate(obj);
>>> - return;
>>> + return 0;
>>> case __I915_MADV_PURGED:
>>> - return;
>>> + return 0;
>>> }
>>>
>>> if (flags & I915_SHRINK_WRITEBACK)
>>> i915_gem_object_writeback(obj);
>>> +
>>> + return 0;
>>> }
>>>
>>> /**
>>> @@ -222,8 +227,8 @@ i915_gem_shrink(struct i915_gem_ww_ctx *ww,
>>> }
>>>
>>> if (!__i915_gem_object_put_pages(obj)) {
>>> - try_to_writeback(obj, shrink);
>>> - count += obj->base.size >>
>> PAGE_SHIFT;
>>> + if (!try_to_writeback(obj, shrink))
>>> + count += obj->base.size >>
>> PAGE_SHIFT;
>>> }
>>> if (!ww)
>>> i915_gem_object_unlock(obj);
>>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>>> index a77e90f300fe..c7402995a8f9 100644
>>> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>>> @@ -35,6 +35,8 @@
>>> * @ttm: The base TTM page vector.
>>> * @dev: The struct device used for dma mapping and unmapping.
>>> * @cached_st: The cached scatter-gather table.
>>> + * @is_shmem: Set if using shmem.
>>> + * @filp: The shmem file, if using shmem backend.
>>> *
>>> * Note that DMA may be going on right up to the point where the page-
>>> * vector is unpopulated in delayed destroy. Hence keep the @@ -46,6
>> +48,9 @@ struct i915_ttm_tt {
>>> struct ttm_tt ttm;
>>> struct device *dev;
>>> struct sg_table *cached_st;
>>> +
>>> + bool is_shmem;
>>> + struct file *filp;
>>> };
>>>
>>> static const struct ttm_place sys_placement_flags = { @@ -179,12 +184,90
>> @@ i915_ttm_placement_from_obj(const struct drm_i915_gem_object *obj,
>>> placement->busy_placement = busy;
>>> }
>>>
>>> +static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev,
>>> + struct ttm_tt *ttm,
>>> + struct ttm_operation_ctx *ctx) {
>>> + struct drm_i915_private *i915 = container_of(bdev, typeof(*i915),
>> bdev);
>>> + struct intel_memory_region *mr = i915-
>>> mm.regions[INTEL_MEMORY_SYSTEM];
>>> + struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt),
>> ttm);
>>> + const unsigned int max_segment = i915_sg_segment_size();
>>> + const size_t size = ttm->num_pages << PAGE_SHIFT;
>>> + struct file *filp = i915_tt->filp;
>>> + struct sgt_iter sgt_iter;
>>> + struct sg_table *st;
>>> + struct page *page;
>>> + unsigned long i;
>>> + int err;
>>> +
>>> + if (!filp) {
>>> + struct address_space *mapping;
>>> + gfp_t mask;
>>> +
>>> + filp = shmem_file_setup("i915-shmem-tt", size,
>> VM_NORESERVE);
>>> + if (IS_ERR(filp))
>>> + return PTR_ERR(filp);
>>> +
>>> + mask = GFP_HIGHUSER | __GFP_RECLAIMABLE;
>>> +
>>> + mapping = filp->f_mapping;
>>> + mapping_set_gfp_mask(mapping, mask);
>>> + GEM_BUG_ON(!(mapping_gfp_mask(mapping) &
>> __GFP_RECLAIM));
>>> +
>>> + i915_tt->filp = filp;
>>> + }
>>> +
>>> + st = shmem_alloc_st(i915, size, mr, filp->f_mapping, max_segment);
>>> + if (IS_ERR(st))
>>> + return PTR_ERR(st);
>>> +
>>> + err = dma_map_sg_attrs(i915_tt->dev,
>>> + st->sgl, st->nents,
>>> + PCI_DMA_BIDIRECTIONAL,
>>> + DMA_ATTR_SKIP_CPU_SYNC |
>>> + DMA_ATTR_NO_KERNEL_MAPPING |
>>> + DMA_ATTR_NO_WARN);
>>> + if (err <= 0) {
>>> + err = -EINVAL;
>>> + goto err_free_st;
>>> + }
>>> +
>>> + i = 0;
>>> + for_each_sgt_page(page, sgt_iter, st)
>>> + ttm->pages[i++] = page;
>>> +
>>> + if (ttm->page_flags & TTM_TT_FLAG_SWAPPED)
>>> + ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
>>> +
>>> + i915_tt->cached_st = st;
>>> + return 0;
>>> +
>>> +err_free_st:
>>> + shmem_free_st(st, filp->f_mapping, false, false);
>>> + return err;
>>> +}
>>> +
>>> +static void i915_ttm_tt_shmem_unpopulate(struct ttm_tt *ttm) {
>>> + struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt),
>> ttm);
>>> + bool backup = ttm->page_flags & TTM_TT_FLAG_SWAPPED;
>>> +
>>> + dma_unmap_sg(i915_tt->dev, i915_tt->cached_st->sgl,
>>> + i915_tt->cached_st->nents,
>>> + PCI_DMA_BIDIRECTIONAL);
>>> +
>>> + shmem_free_st(fetch_and_zero(&i915_tt->cached_st),
>>> + file_inode(i915_tt->filp)->i_mapping,
>>> + backup, backup);
>>>
>>> Should we do something to undo the shmem_file_setup operation here?
>> From its implementation it does take a reference counter of inode and
>> allocate file:
>> https://elixir.bootlin.com/linux/latest/source/mm/shmem.c#L4084
>>>
>>> Regards,
>>> Oak
>>
>> Hi, Oak,
>>
>> That's done in i915_ttm_tt_destroy() afaict.
>>
>> /Thomas
>
> Do we know whether this tt is back by a shmem at create time? If yes, I think a better place to do the shmem_file_setup is in i915_ttm_tt_create - this pairs with the fput in i915_ttm_tt_destroy. If we don't have such information at tt create time, I agree with the current approach.
IIRC the tt_create is called even if the object will mostly likely just
end up being placed in VRAM, so calling shmem_file_setup in there seemed
potentially wasteful, since the shmem file might never even be needed.
Hence keeping it in populate instead.
>
> Regards,
> Oak
>
>>
>>
>>
>>>
>>> +}
>>> +
>>> static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo,
>>> uint32_t page_flags)
>>> {
>>> struct ttm_resource_manager *man =
>>> ttm_manager_type(bo->bdev, bo->resource->mem_type);
>>> struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
>>> + enum ttm_caching caching = i915_ttm_select_tt_caching(obj);
>>> struct i915_ttm_tt *i915_tt;
>>> int ret;
>>>
>>> @@ -196,36 +279,62 @@ static struct ttm_tt *i915_ttm_tt_create(struct
>> ttm_buffer_object *bo,
>>> man->use_tt)
>>> page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
>>>
>>> - ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags,
>>> - i915_ttm_select_tt_caching(obj));
>>> - if (ret) {
>>> - kfree(i915_tt);
>>> - return NULL;
>>> + if (i915_gem_object_is_shrinkable(obj) && caching == ttm_cached) {
>>> + page_flags |= TTM_TT_FLAG_EXTERNAL |
>>> + TTM_TT_FLAG_EXTERNAL_MAPPABLE;
>>> + i915_tt->is_shmem = true;
>>> }
>>>
>>> + ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching);
>>> + if (ret)
>>> + goto err_free;
>>> +
>>> i915_tt->dev = obj->base.dev->dev;
>>>
>>> return &i915_tt->ttm;
>>> +
>>> +err_free:
>>> + kfree(i915_tt);
>>> + return NULL;
>>> +}
>>> +
>>> +static int i915_ttm_tt_populate(struct ttm_device *bdev,
>>> + struct ttm_tt *ttm,
>>> + struct ttm_operation_ctx *ctx)
>>> +{
>>> + struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt),
>>> +ttm);
>>> +
>>> + if (i915_tt->is_shmem)
>>> + return i915_ttm_tt_shmem_populate(bdev, ttm, ctx);
>>> +
>>> + return ttm_pool_alloc(&bdev->pool, ttm, ctx);
>>> }
>>>
>>> static void i915_ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt
>> *ttm) {
>>> struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt),
>> ttm);
>>>
>>> - if (i915_tt->cached_st) {
>>> - dma_unmap_sgtable(i915_tt->dev, i915_tt->cached_st,
>>> - DMA_BIDIRECTIONAL, 0);
>>> - sg_free_table(i915_tt->cached_st);
>>> - kfree(i915_tt->cached_st);
>>> - i915_tt->cached_st = NULL;
>>> + if (i915_tt->is_shmem) {
>>> + i915_ttm_tt_shmem_unpopulate(ttm);
>>> + } else {
>>> + if (i915_tt->cached_st) {
>>> + dma_unmap_sgtable(i915_tt->dev, i915_tt-
>>> cached_st,
>>> + DMA_BIDIRECTIONAL, 0);
>>> + sg_free_table(i915_tt->cached_st);
>>> + kfree(i915_tt->cached_st);
>>> + i915_tt->cached_st = NULL;
>>> + }
>>> + ttm_pool_free(&bdev->pool, ttm);
>>> }
>>> - ttm_pool_free(&bdev->pool, ttm);
>>> }
>>>
>>> static void i915_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt
>> *ttm) {
>>> struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt),
>> ttm);
>>>
>>> + if (i915_tt->filp)
>>> + fput(i915_tt->filp);
>>> +
>>> ttm_tt_fini(ttm);
>>> kfree(i915_tt);
>>> }
>>> @@ -235,6 +344,14 @@ static bool i915_ttm_eviction_valuable(struct
>> ttm_buffer_object *bo, {
>>> struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
>>>
>>> + /*
>>> + * EXTERNAL objects should never be swapped out by TTM, instead
>> we need
>>> + * to handle that ourselves. TTM will already skip such objects for us,
>>> + * but we would like to avoid grabbing locks for no good reason.
>>> + */
>>> + if (bo->ttm && bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)
>>> + return -EBUSY;
>>> +
>>> /* Will do for now. Our pinned objects are still on TTM's LRU lists */
>>> return i915_gem_object_evictable(obj); } @@ -328,9 +445,11 @@
>> static void i915_ttm_adjust_gem_after_move(struct drm_i915_gem_object
>> *obj)
>>> i915_gem_object_set_cache_coherency(obj, cache_level); }
>>>
>>> -static void i915_ttm_purge(struct drm_i915_gem_object *obj)
>>> +static int __i915_ttm_purge(struct drm_i915_gem_object *obj)
>>> {
>>> struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
>>> + struct i915_ttm_tt *i915_tt =
>>> + container_of(bo->ttm, typeof(*i915_tt), ttm);
>>> struct ttm_operation_ctx ctx = {
>>> .interruptible = true,
>>> .no_wait_gpu = false,
>>> @@ -339,17 +458,79 @@ static void i915_ttm_purge(struct
>> drm_i915_gem_object *obj)
>>> int ret;
>>>
>>> if (obj->mm.madv == __I915_MADV_PURGED)
>>> - return;
>>> + return 0;
>>>
>>> - /* TTM's purge interface. Note that we might be reentering. */
>>> ret = ttm_bo_validate(bo, &place, &ctx);
>>> - if (!ret) {
>>> - obj->write_domain = 0;
>>> - obj->read_domains = 0;
>>> - i915_ttm_adjust_gem_after_move(obj);
>>> - i915_ttm_free_cached_io_st(obj);
>>> - obj->mm.madv = __I915_MADV_PURGED;
>>> + if (ret)
>>> + return ret;
>>> +
>>> + if (bo->ttm && i915_tt->filp) {
>>> + /*
>>> + * The below fput(which eventually calls shmem_truncate)
>> might
>>> + * be delayed by worker, so when directly called to purge the
>>> + * pages(like by the shrinker) we should try to be more
>>> + * aggressive and release the pages immediately.
>>> + */
>>> + shmem_truncate_range(file_inode(i915_tt->filp),
>>> + 0, (loff_t)-1);
>>> + fput(fetch_and_zero(&i915_tt->filp));
>>> + }
>>> +
>>> + obj->write_domain = 0;
>>> + obj->read_domains = 0;
>>> + i915_ttm_adjust_gem_after_move(obj);
>>> + i915_ttm_free_cached_io_st(obj);
>>> + obj->mm.madv = __I915_MADV_PURGED;
>>> + return 0;
>>> +}
>>> +
>>> +static void i915_ttm_purge(struct drm_i915_gem_object *obj) {
>>> + __i915_ttm_purge(obj);
>>> +}
>>> +
>>> +static int i915_ttm_shrinker_release_pages(struct drm_i915_gem_object
>> *obj,
>>> + bool should_writeback)
>>> +{
>>> + struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
>>> + struct i915_ttm_tt *i915_tt =
>>> + container_of(bo->ttm, typeof(*i915_tt), ttm);
>>> + struct ttm_operation_ctx ctx = {
>>> + .interruptible = true,
>>> + .no_wait_gpu = false,
>>> + };
>>> + struct ttm_placement place = {};
>>> + int ret;
>>> +
>>> + if (!bo->ttm || bo->resource->mem_type != TTM_PL_SYSTEM)
>>> + return 0;
>>> +
>>> + GEM_BUG_ON(!i915_tt->is_shmem);
>>> +
>>> + if (!i915_tt->filp)
>>> + return 0;
>>> +
>>> + switch (obj->mm.madv) {
>>> + case I915_MADV_DONTNEED:
>>> + return __i915_ttm_purge(obj);
>>> + case __I915_MADV_PURGED:
>>> + return 0;
>>> + }
>>> +
>>> + if (bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED)
>>> + return 0;
>>> +
>>> + bo->ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
>>> + ret = ttm_bo_validate(bo, &place, &ctx);
>>> + if (ret) {
>>> + bo->ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
>>> + return ret;
>>> }
>>> +
>>> + if (should_writeback)
>>> + __shmem_writeback(obj->base.size, i915_tt->filp-
>>> f_mapping);
>>> +
>>> + return 0;
>>> }
>>>
>>> static void i915_ttm_swap_notify(struct ttm_buffer_object *bo) @@ -
>> 618,6 +799,7 @@ static unsigned long i915_ttm_io_mem_pfn(struct
>> ttm_buffer_object *bo,
>>>
>>> static struct ttm_device_funcs i915_ttm_bo_driver = {
>>> .ttm_tt_create = i915_ttm_tt_create,
>>> + .ttm_tt_populate = i915_ttm_tt_populate,
>>> .ttm_tt_unpopulate = i915_ttm_tt_unpopulate,
>>> .ttm_tt_destroy = i915_ttm_tt_destroy,
>>> .eviction_valuable = i915_ttm_eviction_valuable, @@ -685,12 +867,17
>> @@ static int __i915_ttm_get_pages(struct drm_i915_gem_object *obj,
>>> }
>>>
>>> if (!i915_gem_object_has_pages(obj)) {
>>> + struct i915_ttm_tt *i915_tt =
>>> + container_of(bo->ttm, typeof(*i915_tt), ttm);
>>> +
>>> /* Object either has a page vector or is an iomem object */
>>> st = bo->ttm ? i915_ttm_tt_get_st(bo->ttm) : obj-
>>> ttm.cached_io_st;
>>> if (IS_ERR(st))
>>> return PTR_ERR(st);
>>>
>>> __i915_gem_object_set_pages(obj, st,
>> i915_sg_dma_sizes(st->sgl));
>>> + if (!bo->ttm || !i915_tt->is_shmem)
>>> + i915_gem_object_make_unshrinkable(obj);
>>> }
>>>
>>> return ret;
>>> @@ -770,6 +957,8 @@ static void i915_ttm_put_pages(struct
>> drm_i915_gem_object *obj, static void i915_ttm_adjust_lru(struct
>> drm_i915_gem_object *obj) {
>>> struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
>>> + struct i915_ttm_tt *i915_tt =
>>> + container_of(bo->ttm, typeof(*i915_tt), ttm);
>>>
>>> /*
>>> * Don't manipulate the TTM LRUs while in TTM bo destruction.
>>> @@ -782,7 +971,10 @@ static void i915_ttm_adjust_lru(struct
>> drm_i915_gem_object *obj)
>>> * Put on the correct LRU list depending on the MADV status
>>> */
>>> spin_lock(&bo->bdev->lru_lock);
>>> - if (obj->mm.madv != I915_MADV_WILLNEED) {
>>> + if (bo->ttm && i915_tt->filp) {
>>> + /* Try to keep shmem_tt from being considered for shrinking.
>> */
>>> + bo->priority = TTM_MAX_BO_PRIORITY - 1;
>>> + } else if (obj->mm.madv != I915_MADV_WILLNEED) {
>>> bo->priority = I915_TTM_PRIO_PURGE;
>>> } else if (!i915_gem_object_has_pages(obj)) {
>>> if (bo->priority < I915_TTM_PRIO_HAS_PAGES) @@ -887,9
>> +1079,12 @@ static const struct drm_i915_gem_object_ops
>> i915_gem_ttm_obj_ops = {
>>> .get_pages = i915_ttm_get_pages,
>>> .put_pages = i915_ttm_put_pages,
>>> .truncate = i915_ttm_purge,
>>> + .shrinker_release_pages = i915_ttm_shrinker_release_pages,
>>> +
>>> .adjust_lru = i915_ttm_adjust_lru,
>>> .delayed_free = i915_ttm_delayed_free,
>>> .migrate = i915_ttm_migrate,
>>> +
>>> .mmap_offset = i915_ttm_mmap_offset,
>>> .mmap_ops = &vm_ops_ttm,
>>> };
>>> @@ -937,7 +1132,6 @@ int __i915_gem_ttm_object_init(struct
>> intel_memory_region *mem,
>>> drm_gem_private_object_init(&i915->drm, &obj->base, size);
>>> i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class,
>> flags);
>>> i915_gem_object_init_memory_region(obj, mem);
>>> - i915_gem_object_make_unshrinkable(obj);
>>> INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL |
>> __GFP_NOWARN);
>>> mutex_init(&obj->ttm.get_io_page.lock);
>>> bo_type = (obj->flags & I915_BO_ALLOC_USER) ?
>> ttm_bo_type_device :
>>> --
>>> 2.26.3
>>>
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