[PATCH 4/4] drm/mm: Remove DRM_MM_SEARCH_BEST

[Alex Deucher]

On Thu, Oct 30, 2014 at 4:36 AM, Michel Dänzer <michel at daenzer.net> wrote:
> From: Michel Dänzer <michel.daenzer at amd.com>
>
> In the words of Daniel Vetter:
>
> «I think SEARCH_BEST is pretty much always a bad idea - it rips apart
> allocations from the same execbuf, and usually those get recycled around
> the same time. Which means you'll just fragment your mm even more if you
> try to find the best hole instead of just picking one and the stuffing
> the entire execbuf into it. So imo we might as well just kill it.»
>
> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>

Applied this series to my -next tree.

Thanks,

Alex

> ---
>
> This patch replaces the previous patches 4 and 5.
>
> Not sure about the function header comment hunk, maybe what it says is
> true even with DRM_MM_SEARCH_BELOW?
>
>  drivers/gpu/drm/drm_mm.c             | 36 +++++-------------------------------
>  drivers/gpu/drm/ttm/ttm_bo_manager.c |  2 +-
>  include/drm/drm_mm.h                 |  3 +--
>  3 files changed, 7 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
> index 04a209e..3e0ef8c 100644
> --- a/drivers/gpu/drm/drm_mm.c
> +++ b/drivers/gpu/drm/drm_mm.c
> @@ -409,16 +409,11 @@ static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
>                                                       enum drm_mm_search_flags flags)
>  {
>         struct drm_mm_node *entry;
> -       struct drm_mm_node *best;
>         unsigned long adj_start;
>         unsigned long adj_end;
> -       unsigned long best_size;
>
>         BUG_ON(mm->scanned_blocks);
>
> -       best = NULL;
> -       best_size = ~0UL;
> -
>         __drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
>                                flags & DRM_MM_SEARCH_BELOW) {
>                 unsigned long hole_size = adj_end - adj_start;
> @@ -429,19 +424,11 @@ static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
>                                 continue;
>                 }
>
> -               if (!check_free_hole(adj_start, adj_end, size, alignment))
> -                       continue;
> -
> -               if (!(flags & DRM_MM_SEARCH_BEST))
> +               if (check_free_hole(adj_start, adj_end, size, alignment))
>                         return entry;
> -
> -               if (hole_size < best_size) {
> -                       best = entry;
> -                       best_size = hole_size;
> -               }
>         }
>
> -       return best;
> +       return NULL;
>  }
>
>  static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
> @@ -453,16 +440,11 @@ static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_
>                                                         enum drm_mm_search_flags flags)
>  {
>         struct drm_mm_node *entry;
> -       struct drm_mm_node *best;
>         unsigned long adj_start;
>         unsigned long adj_end;
> -       unsigned long best_size;
>
>         BUG_ON(mm->scanned_blocks);
>
> -       best = NULL;
> -       best_size = ~0UL;
> -
>         __drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
>                                flags & DRM_MM_SEARCH_BELOW) {
>                 unsigned long hole_size = adj_end - adj_start;
> @@ -478,19 +460,11 @@ static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_
>                                 continue;
>                 }
>
> -               if (!check_free_hole(adj_start, adj_end, size, alignment))
> -                       continue;
> -
> -               if (!(flags & DRM_MM_SEARCH_BEST))
> +               if (check_free_hole(adj_start, adj_end, size, alignment))
>                         return entry;
> -
> -               if (hole_size < best_size) {
> -                       best = entry;
> -                       best_size = hole_size;
> -               }
>         }
>
> -       return best;
> +       return NULL;
>  }
>
>  /**
> @@ -679,7 +653,7 @@ EXPORT_SYMBOL(drm_mm_scan_add_block);
>   * corrupted.
>   *
>   * When the scan list is empty, the selected memory nodes can be freed. An
> - * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then
> + * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BELOW will then
>   * return the just freed block (because its at the top of the free_stack list).
>   *
>   * Returns:
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_manager.c b/drivers/gpu/drm/ttm/ttm_bo_manager.c
> index aa0bd05..42c2aa9 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_manager.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_manager.c
> @@ -55,7 +55,7 @@ static int ttm_bo_man_get_node(struct ttm_mem_type_manager *man,
>         struct ttm_range_manager *rman = (struct ttm_range_manager *) man->priv;
>         struct drm_mm *mm = &rman->mm;
>         struct drm_mm_node *node = NULL;
> -       enum drm_mm_search_flags sflags = DRM_MM_SEARCH_BEST;
> +       enum drm_mm_search_flags sflags = DRM_MM_SEARCH_DEFAULT;
>         enum drm_mm_allocator_flags aflags = DRM_MM_CREATE_DEFAULT;
>         unsigned long lpfn;
>         int ret;
> diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h
> index a24addf..f38f7a0 100644
> --- a/include/drm/drm_mm.h
> +++ b/include/drm/drm_mm.h
> @@ -46,8 +46,7 @@
>
>  enum drm_mm_search_flags {
>         DRM_MM_SEARCH_DEFAULT =         0,
> -       DRM_MM_SEARCH_BEST =            1 << 0,
> -       DRM_MM_SEARCH_BELOW =           1 << 1,
> +       DRM_MM_SEARCH_BELOW =           1 << 0,
>  };
>
>  enum drm_mm_allocator_flags {
> --
> 2.1.1
>
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