drm/i915: Prefer list_first_entry_or_null

list_first_entry_or_null() can generate better code than using
if (!list_empty()) {ptr = list_first_entry()) ..., so put it to use.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1469432687-22756-3-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469530913-17180-2-git-send-email-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2016-07-26 12:01:51 +01:00
parent 4a50d20e10
commit 2a1d775201
3 changed files with 13 additions and 16 deletions

View file

@ -2736,13 +2736,11 @@ static void i915_gtt_color_adjust(struct drm_mm_node *node,
if (node->color != color)
*start += 4096;
if (!list_empty(&node->node_list)) {
node = list_entry(node->node_list.next,
struct drm_mm_node,
node_list);
if (node->allocated && node->color != color)
*end -= 4096;
}
node = list_first_entry_or_null(&node->node_list,
struct drm_mm_node,
node_list);
if (node && node->allocated && node->color != color)
*end -= 4096;
}
static int i915_gem_setup_global_gtt(struct drm_device *dev,

View file

@ -317,12 +317,10 @@ __i915_gem_request_alloc(struct intel_engine_cs *engine,
return ret;
/* Move the oldest request to the slab-cache (if not in use!) */
if (!list_empty(&engine->request_list)) {
req = list_first_entry(&engine->request_list,
req = list_first_entry_or_null(&engine->request_list,
typeof(*req), list);
if (i915_gem_request_completed(req))
i915_gem_request_retire(req);
}
if (req && i915_gem_request_completed(req))
i915_gem_request_retire(req);
req = kmem_cache_zalloc(dev_priv->requests, GFP_KERNEL);
if (!req)

View file

@ -163,17 +163,18 @@ i915_gem_shrink(struct drm_i915_private *dev_priv,
*/
for (phase = phases; phase->list; phase++) {
struct list_head still_in_list;
struct drm_i915_gem_object *obj;
if ((flags & phase->bit) == 0)
continue;
INIT_LIST_HEAD(&still_in_list);
while (count < target && !list_empty(phase->list)) {
struct drm_i915_gem_object *obj;
while (count < target &&
(obj = list_first_entry_or_null(phase->list,
typeof(*obj),
global_list))) {
struct i915_vma *vma, *v;
obj = list_first_entry(phase->list,
typeof(*obj), global_list);
list_move_tail(&obj->global_list, &still_in_list);
if (flags & I915_SHRINK_PURGEABLE &&