Commit fc896cf3 authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm: Take lru lock once per submit_pin_objects() 



Split out pin_count incrementing and lru updating into a separate loop
so we can take the lru lock only once for all objs.  Since we are still
holding the obj lock, it is safe to split this up.

Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/551025/
parent 6ba5daa5

drivers/gpu/drm/msm/msm_gem.c

+29 −16
Original line number Diff line number Diff line
@@ -222,9 +222,7 @@ static void put_pages(struct drm_gem_object *obj) 
static struct page **msm_gem_pin_pages_locked(struct drm_gem_object *obj,

					      unsigned madv)

{

	struct msm_drm_private *priv = obj->dev->dev_private;

	struct msm_gem_object *msm_obj = to_msm_bo(obj);

	struct page **p;



	msm_gem_assert_locked(obj);
@@ -234,16 +232,29 @@ static struct page **msm_gem_pin_pages_locked(struct drm_gem_object *obj, 
		return ERR_PTR(-EBUSY);

	}



	p = get_pages(obj);

	if (IS_ERR(p))

		return p;

	return get_pages(obj);

}



/*

 * Update the pin count of the object, call under lru.lock

 */

void msm_gem_pin_obj_locked(struct drm_gem_object *obj)

{

	struct msm_drm_private *priv = obj->dev->dev_private;



	msm_gem_assert_locked(obj);



	to_msm_bo(obj)->pin_count++;

	drm_gem_lru_move_tail_locked(&priv->lru.pinned, obj);

}



static void pin_obj_locked(struct drm_gem_object *obj)

{

	struct msm_drm_private *priv = obj->dev->dev_private;



	mutex_lock(&priv->lru.lock);

	msm_obj->pin_count++;

	update_lru_locked(obj);

	msm_gem_pin_obj_locked(obj);

	mutex_unlock(&priv->lru.lock);



	return p;

}



struct page **msm_gem_pin_pages(struct drm_gem_object *obj)
@@ -252,6 +263,8 @@ struct page **msm_gem_pin_pages(struct drm_gem_object *obj) 


	msm_gem_lock(obj);

	p = msm_gem_pin_pages_locked(obj, MSM_MADV_WILLNEED);

	if (!IS_ERR(p))

		pin_obj_locked(obj);

	msm_gem_unlock(obj);



	return p;
@@ -463,7 +476,7 @@ int msm_gem_pin_vma_locked(struct drm_gem_object *obj, struct msm_gem_vma *vma) 
{

	struct msm_gem_object *msm_obj = to_msm_bo(obj);

	struct page **pages;

	int ret, prot = IOMMU_READ;

	int prot = IOMMU_READ;



	if (!(msm_obj->flags & MSM_BO_GPU_READONLY))

		prot |= IOMMU_WRITE;
@@ -480,11 +493,7 @@ int msm_gem_pin_vma_locked(struct drm_gem_object *obj, struct msm_gem_vma *vma) 
	if (IS_ERR(pages))

		return PTR_ERR(pages);



	ret = msm_gem_vma_map(vma, prot, msm_obj->sgt, obj->size);

	if (ret)

		msm_gem_unpin_locked(obj);



	return ret;

	return msm_gem_vma_map(vma, prot, msm_obj->sgt, obj->size);

}



void msm_gem_unpin_locked(struct drm_gem_object *obj)
@@ -536,8 +545,10 @@ static int get_and_pin_iova_range_locked(struct drm_gem_object *obj, 
		return PTR_ERR(vma);



	ret = msm_gem_pin_vma_locked(obj, vma);

	if (!ret)

	if (!ret) {

		*iova = vma->iova;

		pin_obj_locked(obj);

	}



	return ret;

}
@@ -700,6 +711,8 @@ static void *get_vaddr(struct drm_gem_object *obj, unsigned madv) 
	if (IS_ERR(pages))

		return ERR_CAST(pages);



	pin_obj_locked(obj);



	/* increment vmap_count *before* vmap() call, so shrinker can

	 * check vmap_count (is_vunmapable()) outside of msm_obj lock.

	 * This guarantees that we won't try to msm_gem_vunmap() this

drivers/gpu/drm/msm/msm_gem.h

+1 −0
Original line number Diff line number Diff line
@@ -142,6 +142,7 @@ int msm_gem_get_and_pin_iova(struct drm_gem_object *obj, 
		struct msm_gem_address_space *aspace, uint64_t *iova);

void msm_gem_unpin_iova(struct drm_gem_object *obj,

		struct msm_gem_address_space *aspace);

void msm_gem_pin_obj_locked(struct drm_gem_object *obj);

struct page **msm_gem_pin_pages(struct drm_gem_object *obj);

void msm_gem_unpin_pages(struct drm_gem_object *obj);

int msm_gem_dumb_create(struct drm_file *file, struct drm_device *dev,

drivers/gpu/drm/msm/msm_gem_submit.c

+16 −1
Original line number Diff line number Diff line
@@ -384,6 +384,7 @@ static int submit_fence_sync(struct msm_gem_submit *submit, bool no_implicit) 


static int submit_pin_objects(struct msm_gem_submit *submit)

{

	struct msm_drm_private *priv = submit->dev->dev_private;

	int i, ret = 0;



	submit->valid = true;
@@ -403,7 +404,7 @@ static int submit_pin_objects(struct msm_gem_submit *submit) 
		if (ret)

			break;



		submit->bos[i].flags |= BO_OBJ_PINNED | BO_VMA_PINNED;

		submit->bos[i].flags |= BO_VMA_PINNED;

		submit->bos[i].vma = vma;



		if (vma->iova == submit->bos[i].iova) {
@@ -416,6 +417,20 @@ static int submit_pin_objects(struct msm_gem_submit *submit) 
		}

	}



	/*

	 * A second loop while holding the LRU lock (a) avoids acquiring/dropping

	 * the LRU lock for each individual bo, while (b) avoiding holding the

	 * LRU lock while calling msm_gem_pin_vma_locked() (which could trigger

	 * get_pages() which could trigger reclaim.. and if we held the LRU lock

	 * could trigger deadlock with the shrinker).

	 */

	mutex_lock(&priv->lru.lock);

	for (i = 0; i < submit->nr_bos; i++) {

		msm_gem_pin_obj_locked(submit->bos[i].obj);

		submit->bos[i].flags |= BO_OBJ_PINNED;

	}

	mutex_unlock(&priv->lru.lock);



	return ret;

}