[PATCH 2/3] drm/ttm: fix object deallocation to properly fill in the page pool.

[Jérôme Glisse]

From: Jérôme Glisse <jglisse at redhat.com>

Current code never allowed the page pool to actualy fill in anyway. This fix
it and also allow it to grow over its limit until it grow beyond the batch
size for allocation and deallocation.

Signed-off-by: Jérôme Glisse <jglisse at redhat.com>
Reviewed-by: Mario Kleiner <mario.kleiner.de at gmail.com>
Tested-by: Michel Dänzer <michel at daenzer.net>
Cc: Thomas Hellstrom <thellstrom at vmware.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
---
 drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
index c96db43..a076ff3 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -953,14 +953,9 @@ 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) {
+		if (pool->npages_free >= (_manager->options.max_size +
+					  NUM_PAGES_TO_ALLOC))
 			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);
 
-- 
1.9.3