[dm-devel] [PATCH 04/29] drm/msm: dynamically allocate the drm-msm_gem shrinker

[Qi Zheng]

In preparation for implementing lockless slab shrink,
we need to dynamically allocate the drm-msm_gem shrinker,
so that it can be freed asynchronously using kfree_rcu().
Then it doesn't need to wait for RCU read-side critical
section when releasing the struct msm_drm_private.

Signed-off-by: Qi Zheng <zhengqi.a...@bytedance.com>
---
 drivers/gpu/drm/msm/msm_drv.h          |  2 +-
 drivers/gpu/drm/msm/msm_gem_shrinker.c | 25 ++++++++++++++-----------
 2 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index e13a8cbd61c9..4f3ba55058cd 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -217,7 +217,7 @@ struct msm_drm_private {
        } vram;
 
        struct notifier_block vmap_notifier;
-       struct shrinker shrinker;
+       struct shrinker *shrinker;
 
        struct drm_atomic_state *pm_state;
 
diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c 
b/drivers/gpu/drm/msm/msm_gem_shrinker.c
index f38296ad8743..db7582ae1f19 100644
--- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
+++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
@@ -34,8 +34,7 @@ static bool can_block(struct shrink_control *sc)
 static unsigned long
 msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
 {
-       struct msm_drm_private *priv =
-               container_of(shrinker, struct msm_drm_private, shrinker);
+       struct msm_drm_private *priv = shrinker->private_data;
        unsigned count = priv->lru.dontneed.count;
 
        if (can_swap())
@@ -100,8 +99,7 @@ active_evict(struct drm_gem_object *obj)
 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);
+       struct msm_drm_private *priv = shrinker->private_data;
        struct {
                struct drm_gem_lru *lru;
                bool (*shrink)(struct drm_gem_object *obj);
@@ -151,7 +149,7 @@ msm_gem_shrinker_shrink(struct drm_device *dev, unsigned 
long nr_to_scan)
        int ret;
 
        fs_reclaim_acquire(GFP_KERNEL);
-       ret = msm_gem_shrinker_scan(&priv->shrinker, &sc);
+       ret = msm_gem_shrinker_scan(priv->shrinker, &sc);
        fs_reclaim_release(GFP_KERNEL);
 
        return ret;
@@ -213,10 +211,15 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned 
long event, void *ptr)
 void msm_gem_shrinker_init(struct drm_device *dev)
 {
        struct msm_drm_private *priv = dev->dev_private;
-       priv->shrinker.count_objects = msm_gem_shrinker_count;
-       priv->shrinker.scan_objects = msm_gem_shrinker_scan;
-       priv->shrinker.seeks = DEFAULT_SEEKS;
-       WARN_ON(register_shrinker(&priv->shrinker, "drm-msm_gem"));
+
+       priv->shrinker = shrinker_alloc_and_init(msm_gem_shrinker_count,
+                                                msm_gem_shrinker_scan, 0,
+                                                DEFAULT_SEEKS, 0, priv);
+       if (priv->shrinker &&
+           register_shrinker(priv->shrinker, "drm-msm_gem")) {
+               shrinker_free(priv->shrinker);
+               WARN_ON(1);
+       }
 
        priv->vmap_notifier.notifier_call = msm_gem_shrinker_vmap;
        WARN_ON(register_vmap_purge_notifier(&priv->vmap_notifier));
@@ -232,8 +235,8 @@ void msm_gem_shrinker_cleanup(struct drm_device *dev)
 {
        struct msm_drm_private *priv = dev->dev_private;
 
-       if (priv->shrinker.nr_deferred) {
+       if (priv->shrinker->nr_deferred) {
                WARN_ON(unregister_vmap_purge_notifier(&priv->vmap_notifier));
-               unregister_shrinker(&priv->shrinker);
+               unregister_and_free_shrinker(priv->shrinker);
        }
 }
-- 
2.30.2

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