Use rw_semaphore instead of mutex for bo_lists.
In original function amdgpu_bo_list_get, the waiting
for result->lock can be quite long while mutex
bo_list_lock was holding. It can make other tasks
waiting for bo_list_lock for long period too.
Change bo_list_lock to rw_semaphore can avoid most of
such long waiting.
Secondly, this patch allows several tasks(readers of idr)
to proceed at the same time.
Signed-off-by: Alex Xie <AlexBin.Xie at amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 3 ++-
drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c | 14 +++++++-------
drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 3 +--
3 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 063fc73..bfc40d7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -35,6 +35,7 @@
#include <linux/rbtree.h>
#include <linux/hashtable.h>
#include <linux/dma-fence.h>
+#include <linux/rwsem.h>
#include <ttm/ttm_bo_api.h>
#include <ttm/ttm_bo_driver.h>
@@ -859,7 +860,7 @@ void amdgpu_ctx_mgr_fini(struct amdgpu_ctx_mgr *mgr);
struct amdgpu_fpriv {
struct amdgpu_vm vm;
struct amdgpu_bo_va *prt_va;
- struct mutex bo_list_lock;
+ struct rw_semaphore bo_list_lock;
struct idr bo_list_handles;
struct amdgpu_ctx_mgr ctx_mgr;
u32 vram_lost_counter;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
index 4363f28..bfe736e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
@@ -45,10 +45,10 @@ static int amdgpu_bo_list_create(struct amdgpu_fpriv *fpriv,
if (!*result)
return -ENOMEM;
- mutex_lock(&fpriv->bo_list_lock);
+ down_read(&fpriv->bo_list_lock);
r = idr_alloc(&fpriv->bo_list_handles, *result,
1, 0, GFP_KERNEL);
- mutex_unlock(&fpriv->bo_list_lock);
+ up_read(&fpriv->bo_list_lock);
if (r < 0) {
kfree(*result);
@@ -67,17 +67,17 @@ static void amdgpu_bo_list_destroy(struct amdgpu_fpriv *fpriv, int id)
{
struct amdgpu_bo_list *list;
- mutex_lock(&fpriv->bo_list_lock);
+ down_write(&fpriv->bo_list_lock);
list = idr_remove(&fpriv->bo_list_handles, id);
if (list) {
/* Another user may have a reference to this list still */
mutex_lock(&list->lock);
mutex_unlock(&list->lock);
- mutex_unlock(&fpriv->bo_list_lock);
+ up_write(&fpriv->bo_list_lock);
amdgpu_bo_list_free(list);
}
else {
- mutex_unlock(&fpriv->bo_list_lock);
+ up_write(&fpriv->bo_list_lock);
}
}
@@ -173,11 +173,11 @@ amdgpu_bo_list_get(struct amdgpu_fpriv *fpriv, int id)
{
struct amdgpu_bo_list *result;
- mutex_lock(&fpriv->bo_list_lock);
+ down_read(&fpriv->bo_list_lock);
result = idr_find(&fpriv->bo_list_handles, id);
if (result)
mutex_lock(&result->lock);
- mutex_unlock(&fpriv->bo_list_lock);
+ up_read(&fpriv->bo_list_lock);
return result;
}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index f68ced6..c4cba81 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -841,7 +841,7 @@ int amdgpu_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
goto out_suspend;
}
- mutex_init(&fpriv->bo_list_lock);
+ init_rwsem(&fpriv->bo_list_lock);
idr_init(&fpriv->bo_list_handles);
amdgpu_ctx_mgr_init(&fpriv->ctx_mgr);
@@ -900,7 +900,6 @@ void amdgpu_driver_postclose_kms(struct drm_device *dev,
amdgpu_bo_list_free(list);
idr_destroy(&fpriv->bo_list_handles);
- mutex_destroy(&fpriv->bo_list_lock);
kfree(fpriv);
file_priv->driver_priv = NULL;
--
2.7.4
