[PATCH 2/8] drm/msm: Reorganize msm_gem_shrinker_scan()

Rob Clark
2021-04-05T17:42:13Z

So we don't have to duplicate the boilerplate for eviction.

This also lets us re-use the main scan loop for vmap shrinker.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
drivers/gpu/drm/msm/msm_gem_shrinker.c | 94 +++++++++++++-------------
1 file changed, 46 insertions(+), 48 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c
index 33a49641ef30..38bf919f8508 100644
--- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
+++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
@@ -17,21 +17,35 @@ msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
return priv->shrinkable_count;
}

+static bool
+purge(struct msm_gem_object *msm_obj)
+{
+ if (!is_purgeable(msm_obj))
+ return false;
+
+ /*
+ * This will move the obj out of still_in_list to
+ * the purged list
+ */
+ msm_gem_purge(&msm_obj->base);
+
+ return true;
+}
+
static unsigned long
-msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
+scan(struct msm_drm_private *priv, unsigned nr_to_scan, struct list_head *list,
+ bool (*shrink)(struct msm_gem_object *msm_obj))
{
- struct msm_drm_private *priv =
- container_of(shrinker, struct msm_drm_private, shrinker);
+ unsigned freed = 0;
struct list_head still_in_list;
- unsigned long freed = 0;

INIT_LIST_HEAD(&still_in_list);

mutex_lock(&priv->mm_lock);

- while (freed < sc->nr_to_scan) {
+ while (freed < nr_to_scan) {
struct msm_gem_object *msm_obj = list_first_entry_or_null(
- &priv->inactive_dontneed, typeof(*msm_obj), mm_list);
+ list, typeof(*msm_obj), mm_list);

if (!msm_obj)
break;
@@ -62,14 +76,9 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
if (!msm_gem_trylock(&msm_obj->base))
goto tail;

- if (is_purgeable(msm_obj)) {
- /*
- * This will move the obj out of still_in_list to
- * the purged list
- */
- msm_gem_purge(&msm_obj->base);
+ if (shrink(msm_obj))
freed += msm_obj->base.size >> PAGE_SHIFT;
- }
+
msm_gem_unlock(&msm_obj->base);

tail:
@@ -77,16 +86,25 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
mutex_lock(&priv->mm_lock);
}

- list_splice_tail(&still_in_list, &priv->inactive_dontneed);
+ list_splice_tail(&still_in_list, list);
mutex_unlock(&priv->mm_lock);

- if (freed > 0) {
+ return freed;
+}
+
+static unsigned long
+msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
+{
+ struct msm_drm_private *priv =
+ container_of(shrinker, struct msm_drm_private, shrinker);
+ unsigned long freed;
+
+ freed = scan(priv, sc->nr_to_scan, &priv->inactive_dontneed, purge);
+
+ if (freed > 0)
trace_msm_gem_purge(freed << PAGE_SHIFT);
- } else {
- return SHRINK_STOP;
- }

- return freed;
+ return (freed > 0) ? freed : SHRINK_STOP;
}

/* since we don't know any better, lets bail after a few
@@ -95,29 +113,15 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
*/
static const int vmap_shrink_limit = 15;

-static unsigned
-vmap_shrink(struct list_head *mm_list)
+static bool
+vmap_shrink(struct msm_gem_object *msm_obj)
{
- struct msm_gem_object *msm_obj;
- unsigned unmapped = 0;
+ if (!is_vunmapable(msm_obj))
+ return false;

- list_for_each_entry(msm_obj, mm_list, mm_list) {
- /* Use trylock, because we cannot block on a obj that
- * might be trying to acquire mm_lock
- */
- if (!msm_gem_trylock(&msm_obj->base))
- continue;
- if (is_vunmapable(msm_obj)) {
- msm_gem_vunmap(&msm_obj->base);
- unmapped++;
- }
- msm_gem_unlock(&msm_obj->base);
+ msm_gem_vunmap(&msm_obj->base);

- if (++unmapped >= vmap_shrink_limit)
- break;
- }
-
- return unmapped;
+ return true;
}

static int
@@ -133,17 +137,11 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
};
unsigned idx, unmapped = 0;

- mutex_lock(&priv->mm_lock);
-
- for (idx = 0; mm_lists[idx]; idx++) {
- unmapped += vmap_shrink(mm_lists[idx]);
-
- if (unmapped >= vmap_shrink_limit)
- break;
+ for (idx = 0; mm_lists[idx] && unmapped < vmap_shrink_limit; idx++) {
+ unmapped += scan(priv, vmap_shrink_limit - unmapped,
+ mm_lists[idx], vmap_shrink);
}

- mutex_unlock(&priv->mm_lock);
-
*(unsigned long *)ptr += unmapped;

if (unmapped > 0)
--
2.30.2