[PATCH 18/28] drm/vmwgfx: Avoid cmdbuf alloc sleeping if !TASK_RUNNING
Thomas Hellstrom
thellstrom at vmware.com
Wed Aug 12 22:43:07 PDT 2015
If the command buffer pool is out of space, the code waits until space is
available. However since the condition code tries to allocate a range manager
node while !TASK_RUNNING we get a kernel warning.
Avoid this by pre-allocating the mm node. This will also probably be more
efficient.
Signed-off-by: Thomas Hellstrom <thellstrom at vmware.com>
Reviewed-by: Sinclair Yeh <syeh at vmware.com>
---
drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c | 83 ++++++++++++++--------------------
1 file changed, 34 insertions(+), 49 deletions(-)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c
index b044bf5..e94feb3 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c
@@ -33,7 +33,8 @@
* multiple of the DMA pool allocation size.
*/
#define VMW_CMDBUF_INLINE_ALIGN 64
-#define VMW_CMDBUF_INLINE_SIZE (1024 - VMW_CMDBUF_INLINE_ALIGN)
+#define VMW_CMDBUF_INLINE_SIZE \
+ (1024 - ALIGN(sizeof(SVGACBHeader), VMW_CMDBUF_INLINE_ALIGN))
/**
* struct vmw_cmdbuf_context - Command buffer context queues
@@ -145,7 +146,7 @@ struct vmw_cmdbuf_header {
SVGACBHeader *cb_header;
SVGACBContext cb_context;
struct list_head list;
- struct drm_mm_node *node;
+ struct drm_mm_node node;
dma_addr_t handle;
u8 *cmd;
size_t size;
@@ -169,13 +170,13 @@ struct vmw_cmdbuf_dheader {
* struct vmw_cmdbuf_alloc_info - Command buffer space allocation metadata
*
* @page_size: Size of requested command buffer space in pages.
- * @node: The range manager node if allocation succeeded.
- * @ret: Error code if failure. Otherwise 0.
+ * @node: Pointer to the range manager node.
+ * @done: True if this allocation has succeeded.
*/
struct vmw_cmdbuf_alloc_info {
size_t page_size;
struct drm_mm_node *node;
- int ret;
+ bool done;
};
/* Loop over each context in the command buffer manager. */
@@ -253,9 +254,7 @@ static void __vmw_cmdbuf_header_free(struct vmw_cmdbuf_header *header)
return;
}
- drm_mm_remove_node(header->node);
- kfree(header->node);
- header->node = NULL;
+ drm_mm_remove_node(&header->node);
wake_up_all(&man->alloc_queue);
if (header->cb_header)
dma_pool_free(man->headers, header->cb_header,
@@ -669,32 +668,26 @@ static bool vmw_cmdbuf_try_alloc(struct vmw_cmdbuf_man *man,
{
int ret;
- if (info->node)
+ if (info->done)
return true;
-
- info->node = kzalloc(sizeof(*info->node), GFP_KERNEL);
- if (!info->node) {
- info->ret = -ENOMEM;
- return true;
- }
-
+
+ memset(info->node, 0, sizeof(*info->node));
spin_lock_bh(&man->lock);
- ret = drm_mm_insert_node_generic(&man->mm, info->node, info->page_size, 0, 0,
+ ret = drm_mm_insert_node_generic(&man->mm, info->node, info->page_size,
+ 0, 0,
DRM_MM_SEARCH_DEFAULT,
DRM_MM_CREATE_DEFAULT);
spin_unlock_bh(&man->lock);
- if (ret) {
- kfree(info->node);
- info->node = NULL;
- }
+ info->done = !ret;
- return !!info->node;
+ return info->done;
}
/**
* vmw_cmdbuf_alloc_space - Allocate buffer space from the main pool.
*
* @man: The command buffer manager.
+ * @node: Pointer to pre-allocated range-manager node.
* @size: The size of the allocation.
* @interruptible: Whether to sleep interruptible while waiting for space.
*
@@ -702,15 +695,16 @@ static bool vmw_cmdbuf_try_alloc(struct vmw_cmdbuf_man *man,
* no space available ATM, it turns on IRQ handling and sleeps waiting for it to
* become available.
*/
-static struct drm_mm_node *vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man,
- size_t size,
- bool interruptible)
+int vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man,
+ struct drm_mm_node *node,
+ size_t size,
+ bool interruptible)
{
struct vmw_cmdbuf_alloc_info info;
info.page_size = PAGE_ALIGN(size) >> PAGE_SHIFT;
- info.node = NULL;
- info.ret = 0;
+ info.node = node;
+ info.done = false;
/*
* To prevent starvation of large requests, only one allocating call
@@ -718,22 +712,14 @@ static struct drm_mm_node *vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man,
*/
if (interruptible) {
if (mutex_lock_interruptible(&man->space_mutex))
- return ERR_PTR(-ERESTARTSYS);
+ return -ERESTARTSYS;
} else {
mutex_lock(&man->space_mutex);
}
/* Try to allocate space without waiting. */
- (void) vmw_cmdbuf_try_alloc(man, &info);
- if (info.ret && !info.node) {
- mutex_unlock(&man->space_mutex);
- return ERR_PTR(info.ret);
- }
-
- if (info.node) {
- mutex_unlock(&man->space_mutex);
- return info.node;
- }
+ if (vmw_cmdbuf_try_alloc(man, &info))
+ goto out_unlock;
vmw_generic_waiter_add(man->dev_priv,
SVGA_IRQFLAG_COMMAND_BUFFER,
@@ -749,7 +735,7 @@ static struct drm_mm_node *vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man,
(man->dev_priv, SVGA_IRQFLAG_COMMAND_BUFFER,
&man->dev_priv->cmdbuf_waiters);
mutex_unlock(&man->space_mutex);
- return ERR_PTR(ret);
+ return ret;
}
} else {
wait_event(man->alloc_queue, vmw_cmdbuf_try_alloc(man, &info));
@@ -757,11 +743,11 @@ static struct drm_mm_node *vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man,
vmw_generic_waiter_remove(man->dev_priv,
SVGA_IRQFLAG_COMMAND_BUFFER,
&man->dev_priv->cmdbuf_waiters);
+
+out_unlock:
mutex_unlock(&man->space_mutex);
- if (info.ret && !info.node)
- return ERR_PTR(info.ret);
- return info.node;
+ return 0;
}
/**
@@ -785,10 +771,10 @@ static int vmw_cmdbuf_space_pool(struct vmw_cmdbuf_man *man,
if (!man->has_pool)
return -ENOMEM;
- header->node = vmw_cmdbuf_alloc_space(man, size, interruptible);
+ ret = vmw_cmdbuf_alloc_space(man, &header->node, size, interruptible);
- if (IS_ERR(header->node))
- return PTR_ERR(header->node);
+ if (ret)
+ return ret;
header->cb_header = dma_pool_alloc(man->headers, GFP_KERNEL,
&header->handle);
@@ -797,9 +783,9 @@ static int vmw_cmdbuf_space_pool(struct vmw_cmdbuf_man *man,
goto out_no_cb_header;
}
- header->size = header->node->size << PAGE_SHIFT;
+ header->size = header->node.size << PAGE_SHIFT;
cb_hdr = header->cb_header;
- offset = header->node->start << PAGE_SHIFT;
+ offset = header->node.start << PAGE_SHIFT;
header->cmd = man->map + offset;
memset(cb_hdr, 0, sizeof(*cb_hdr));
if (man->using_mob) {
@@ -814,9 +800,8 @@ static int vmw_cmdbuf_space_pool(struct vmw_cmdbuf_man *man,
out_no_cb_header:
spin_lock_bh(&man->lock);
- drm_mm_remove_node(header->node);
+ drm_mm_remove_node(&header->node);
spin_unlock_bh(&man->lock);
- kfree(header->node);
return ret;
}
--
2.1.0
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