drm/ttm: Add a bo list reserve fastpath (v2)
Makes it possible to reserve a list of buffer objects with a single
spin lock / unlock if there is no contention.
Should improve cpu usage on SMP kernels.
v2: Initialize private list members on reserve and don't call
ttm_bo_list_ref_sub() with zero put_count.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 148a322..a586378 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -169,7 +169,7 @@
}
EXPORT_SYMBOL(ttm_bo_wait_unreserved);
-static void ttm_bo_add_to_lru(struct ttm_buffer_object *bo)
+void ttm_bo_add_to_lru(struct ttm_buffer_object *bo)
{
struct ttm_bo_device *bdev = bo->bdev;
struct ttm_mem_type_manager *man;
@@ -191,11 +191,7 @@
}
}
-/**
- * Call with the lru_lock held.
- */
-
-static int ttm_bo_del_from_lru(struct ttm_buffer_object *bo)
+int ttm_bo_del_from_lru(struct ttm_buffer_object *bo)
{
int put_count = 0;
@@ -267,6 +263,15 @@
BUG();
}
+void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
+ bool never_free)
+{
+ while (count--)
+ kref_put(&bo->list_kref,
+ (never_free || (count >= 0)) ? ttm_bo_ref_bug :
+ ttm_bo_release_list);
+}
+
int ttm_bo_reserve(struct ttm_buffer_object *bo,
bool interruptible,
bool no_wait, bool use_sequence, uint32_t sequence)
@@ -282,8 +287,7 @@
put_count = ttm_bo_del_from_lru(bo);
spin_unlock(&glob->lru_lock);
- while (put_count--)
- kref_put(&bo->list_kref, ttm_bo_ref_bug);
+ ttm_bo_list_ref_sub(bo, put_count, true);
return ret;
}
@@ -496,8 +500,7 @@
spin_unlock(&glob->lru_lock);
ttm_bo_cleanup_memtype_use(bo);
- while (put_count--)
- kref_put(&bo->list_kref, ttm_bo_ref_bug);
+ ttm_bo_list_ref_sub(bo, put_count, true);
return;
} else {
@@ -580,8 +583,7 @@
spin_unlock(&glob->lru_lock);
ttm_bo_cleanup_memtype_use(bo);
- while (put_count--)
- kref_put(&bo->list_kref, ttm_bo_ref_bug);
+ ttm_bo_list_ref_sub(bo, put_count, true);
return 0;
}
@@ -802,8 +804,7 @@
BUG_ON(ret != 0);
- while (put_count--)
- kref_put(&bo->list_kref, ttm_bo_ref_bug);
+ ttm_bo_list_ref_sub(bo, put_count, true);
ret = ttm_bo_evict(bo, interruptible, no_wait_reserve, no_wait_gpu);
ttm_bo_unreserve(bo);
@@ -1783,8 +1784,7 @@
put_count = ttm_bo_del_from_lru(bo);
spin_unlock(&glob->lru_lock);
- while (put_count--)
- kref_put(&bo->list_kref, ttm_bo_ref_bug);
+ ttm_bo_list_ref_sub(bo, put_count, true);
/**
* Wait for GPU, then move to system cached.