Re: [PATCH 1/2] drm/ttm: swap consecutive allocated cached pages v3

On 2017-12-04 01:46 PM, Christian König wrote:

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

v2: use swap v3: check if it's really the first allocated page

Signed-off-by: Christian König christian.koenig@amd.com

drivers/gpu/drm/ttm/ttm_page_alloc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c index c82d94cbbabc..7c4d4edce0ba 100644 --- a/drivers/gpu/drm/ttm/ttm_page_alloc.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c @@ -875,7 +875,7 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags, #endif struct list_head plist; struct page *p = NULL;

• unsigned count;

• unsigned count, first; int r;

  /* No pool for cached pages */

@@ -914,6 +914,7 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags, } #endif

• first = i;
  

  while (npages) { p = alloc_page(gfp_flags); if (!p) {

@@ -921,6 +922,10 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags, return -ENOMEM; }

• 	/* Swap the pages if we detect consecutive order */
  

• 	if (i > first && pages[i - 1] == p - 1)
  

• 		swap(p, pages[i - 1]);
  

• pages[i++] = p;
  --npages;
  

  }

Both patches are

Reviewed-by: Michel Dänzer michel.daenzer@amd.com