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

[Konrad Rzeszutek Wilk]

On Tue, Aug 12, 2014 at 11:52:05PM -0400, Jérôme Glisse wrote:
> 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>

Reviewed-by: 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
>