[PATCH] drm/ttm: Don't evict BOs outside of the requested placement range
Christian König
deathsimple at vodafone.de
Thu Oct 9 02:53:00 PDT 2014
Am 09.10.2014 um 08:02 schrieb Michel Dänzer:
> From: Michel Dänzer <michel.daenzer at amd.com>
>
> The radeon driver uses placement range restrictions for several reasons,
> in particular to make sure BOs in VRAM can be accessed by the CPU, e.g.
> during a page fault.
>
> Without this change, TTM could evict other BOs while trying to satisfy
> the requested placement, even if the evicted BOs were outside of the
> requested placement range. Doing so didn't free up any space in the
> requested placement range, so the (potentially high) eviction cost was
> incurred for no benefit.
>
> Nominating for stable because radeon driver changes in 3.17 made this
> much more noticeable than before.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=84662
> Cc: stable at vger.kernel.org
> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
Reviewed-by: Christian König <christian.koenig at amd.com>
> ---
> drivers/gpu/drm/ttm/ttm_bo.c | 20 +++++++++++++++++---
> 1 file changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index 8f5cec6..407fa2d 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -709,6 +709,7 @@ out:
>
> static int ttm_mem_evict_first(struct ttm_bo_device *bdev,
> uint32_t mem_type,
> + const struct ttm_place *place,
> bool interruptible,
> bool no_wait_gpu)
> {
> @@ -720,8 +721,21 @@ static int ttm_mem_evict_first(struct ttm_bo_device *bdev,
> spin_lock(&glob->lru_lock);
> list_for_each_entry(bo, &man->lru, lru) {
> ret = __ttm_bo_reserve(bo, false, true, false, NULL);
> - if (!ret)
> + if (!ret) {
> + if (place && (place->fpfn || place->lpfn)) {
> + /* Don't evict this BO if it's outside of the
> + * requested placement range
> + */
> + if (place->fpfn >= (bo->mem.start + bo->mem.size) ||
> + (place->lpfn && place->lpfn <= bo->mem.start)) {
> + __ttm_bo_unreserve(bo);
> + ret = -EBUSY;
> + continue;
> + }
> + }
> +
> break;
> + }
> }
>
> if (ret) {
> @@ -782,7 +796,7 @@ static int ttm_bo_mem_force_space(struct ttm_buffer_object *bo,
> return ret;
> if (mem->mm_node)
> break;
> - ret = ttm_mem_evict_first(bdev, mem_type,
> + ret = ttm_mem_evict_first(bdev, mem_type, place,
> interruptible, no_wait_gpu);
> if (unlikely(ret != 0))
> return ret;
> @@ -1233,7 +1247,7 @@ static int ttm_bo_force_list_clean(struct ttm_bo_device *bdev,
> spin_lock(&glob->lru_lock);
> while (!list_empty(&man->lru)) {
> spin_unlock(&glob->lru_lock);
> - ret = ttm_mem_evict_first(bdev, mem_type, false, false);
> + ret = ttm_mem_evict_first(bdev, mem_type, NULL, false, false);
> if (ret) {
> if (allow_errors) {
> return ret;
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