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Commit 2c05114d authored by Konrad Rzeszutek Wilk's avatar Konrad Rzeszutek Wilk Committed by Dave Airlie
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drm/ttm/dma: Fix accounting error when calling ttm_mem_global_free_page and... 


drm/ttm/dma: Fix accounting error when calling ttm_mem_global_free_page and don't try to free freed pages.

The code to figure out how many pages to shrink the pool
ends up capping the 'count' at _manager->options.max_size - which is OK.
Except that the 'count' is also used when accounting for how many pages
are recycled - which we end up with the invalid values. This fixes
it by using a different value for the amount of pages to shrink.

On top of that we would free the cached page pool - which is nonsense
as they are deleted from the pool - so there are no free pages in that
pool..

Also we also missed the opportunity to batch the amount of pages
to free (similar to how ttm_page_alloc.c does it). This reintroduces
the code that was lost during rebasing.

Reviewed-by: default avatarJerome Glisse <jglisse@redhat.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 36d7c537

drivers/gpu/drm/ttm/ttm_page_alloc_dma.c

+10 −5
Original line number Diff line number Diff line
@@ -949,7 +949,7 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) 
	struct dma_page *d_page, *next;

	enum pool_type type;

	bool is_cached = false;

	unsigned count = 0, i;

	unsigned count = 0, i, npages = 0;

	unsigned long irq_flags;



	type = ttm_to_type(ttm->page_flags, ttm->caching_state);
@@ -974,8 +974,13 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) 
	} else {

		pool->npages_free += count;

		list_splice(&ttm_dma->pages_list, &pool->free_list);

		npages = count;

		if (pool->npages_free > _manager->options.max_size) {

			count = pool->npages_free - _manager->options.max_size;

			npages = pool->npages_free - _manager->options.max_size;

			/* free at least NUM_PAGES_TO_ALLOC number of pages

			 * to reduce calls to set_memory_wb */

			if (npages < NUM_PAGES_TO_ALLOC)

				npages = NUM_PAGES_TO_ALLOC;

		}

	}

	spin_unlock_irqrestore(&pool->lock, irq_flags);
@@ -999,9 +1004,9 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) 
		ttm_dma->dma_address[i] = 0;

	}



	/* shrink pool if necessary */

	if (count)

		ttm_dma_page_pool_free(pool, count);

	/* shrink pool if necessary (only on !is_cached pools)*/

	if (npages)

		ttm_dma_page_pool_free(pool, npages);

	ttm->state = tt_unpopulated;

}

EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);