[PATCH 1/2] drm/ttm: swap consecutive allocated cached pages v2

Christian König ckoenig.leichtzumerken at gmail.com
Mon Dec 4 12:12:32 UTC 2017


When we detect consecutive allocation of pages swap them to avoid
accidentally freeing them as huge page.

v2: use swap

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/ttm/ttm_page_alloc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index c82d94cbbabc..b6c5148607e9 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -921,6 +921,10 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
 				return -ENOMEM;
 			}
 
+			/* Swap the pages if we detect consecutive order */
+			if (i && pages[i - 1] == p - 1)
+				swap(p, pages[i - 1]);
+
 			pages[i++] = p;
 			--npages;
 		}
-- 
2.11.0



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