[PATCH v6] dma-buf: add some tracepoints to debug.

[PATCH v6] dma-buf: add some tracepoints to debug.

[Xiang Gao]

From: gaoxiang17 <gaoxiang17@xiaomi.com>

Since we can only inspect dmabuf by iterating over process FDs or the
dmabuf_list, we need to add our own tracepoints to track its status in
real time in production.

For example:
   binder:3016_1-3102    [006] ...1.   255.126521: dma_buf_export: exp_name=qcom,system size=12685312 ino=2738
   binder:3016_1-3102    [006] ...1.   255.126528: dma_buf_fd: exp_name=qcom,system size=12685312 ino=2738 fd=8
   binder:3016_1-3102    [006] ...1.   255.126642: dma_buf_mmap_internal: exp_name=qcom,system size=28672 ino=2739
     kworker/6:1-86      [006] ...1.   255.127194: dma_buf_put: exp_name=qcom,system size=12685312 ino=2738
    RenderThread-9293    [006] ...1.   316.618179: dma_buf_get: exp_name=qcom,system size=12771328 ino=2762 fd=176
    RenderThread-9293    [006] ...1.   316.618195: dma_buf_dynamic_attach: exp_name=qcom,system size=12771328 ino=2762 attachment:ffffff880a18dd00 is_dynamic=0 dev_name=kgsl-3d0
    RenderThread-9293    [006] ...1.   318.878220: dma_buf_detach: exp_name=qcom,system size=12771328 ino=2762 attachment:ffffff880a18dd00 is_dynamic=0 dev_name=kgsl-3d0

Signed-off-by: Xiang Gao <gaoxiang17@xiaomi.com>
---
 drivers/dma-buf/dma-buf.c      |  42 ++++++++-
 include/trace/events/dma_buf.h | 154 +++++++++++++++++++++++++++++++++
 2 files changed, 195 insertions(+), 1 deletion(-)
 create mode 100644 include/trace/events/dma_buf.h

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 2bcf9ceca997..831973de76c4 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -35,6 +35,25 @@
 
 #include "dma-buf-sysfs-stats.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/dma_buf.h>
+
+/*
+ * dmabuf->name must be accessed with holding dmabuf->name_lock.
+ * we need to take the lock around the tracepoint call itself where
+ * it is called in the code.
+ *
+ * Note: FUNC##_enabled() is a static branch that will only
+ *       be set when the trace event is enabled.
+ */
+#define DMA_BUF_TRACE(FUNC, ...)                  \
+    do {                                          \
+        if (FUNC##_enabled()) {                   \
+            guard(spinlock)(&dmabuf->name_lock); \
+            FUNC(__VA_ARGS__);                    \
+        }                                         \
+    } while (0)
+
 static inline int is_dma_buf_file(struct file *);
 
 static DEFINE_MUTEX(dmabuf_list_mutex);
@@ -220,6 +239,8 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
 	    dmabuf->size >> PAGE_SHIFT)
 		return -EINVAL;
 
+	DMA_BUF_TRACE(trace_dma_buf_mmap_internal, dmabuf);
+
 	return dmabuf->ops->mmap(dmabuf, vma);
 }
 
@@ -745,6 +766,8 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
 
 	__dma_buf_list_add(dmabuf);
 
+	DMA_BUF_TRACE(trace_dma_buf_export, dmabuf);
+
 	return dmabuf;
 
 err_dmabuf:
@@ -779,6 +802,8 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags)
 
 	fd_install(fd, dmabuf->file);
 
+	DMA_BUF_TRACE(trace_dma_buf_fd, dmabuf, fd);
+
 	return fd;
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF");
@@ -794,6 +819,7 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF");
 struct dma_buf *dma_buf_get(int fd)
 {
 	struct file *file;
+	struct dma_buf *dmabuf;
 
 	file = fget(fd);
 
@@ -805,7 +831,11 @@ struct dma_buf *dma_buf_get(int fd)
 		return ERR_PTR(-EINVAL);
 	}
 
-	return file->private_data;
+	dmabuf = file->private_data;
+
+	DMA_BUF_TRACE(trace_dma_buf_get, dmabuf, fd);
+
+	return dmabuf;
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_get, "DMA_BUF");
 
@@ -825,6 +855,8 @@ void dma_buf_put(struct dma_buf *dmabuf)
 		return;
 
 	fput(dmabuf->file);
+
+	DMA_BUF_TRACE(trace_dma_buf_put, dmabuf);
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_put, "DMA_BUF");
 
@@ -979,6 +1011,9 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
 	list_add(&attach->node, &dmabuf->attachments);
 	dma_resv_unlock(dmabuf->resv);
 
+	DMA_BUF_TRACE(trace_dma_buf_dynamic_attach, dmabuf, attach,
+		dma_buf_attachment_is_dynamic(attach), dev);
+
 	return attach;
 
 err_attach:
@@ -1023,6 +1058,9 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
 	if (dmabuf->ops->detach)
 		dmabuf->ops->detach(dmabuf, attach);
 
+	DMA_BUF_TRACE(trace_dma_buf_detach, dmabuf, attach,
+		dma_buf_attachment_is_dynamic(attach), attach->dev);
+
 	kfree(attach);
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_detach, "DMA_BUF");
@@ -1488,6 +1526,8 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
 	vma_set_file(vma, dmabuf->file);
 	vma->vm_pgoff = pgoff;
 
+	DMA_BUF_TRACE(trace_dma_buf_mmap, dmabuf);
+
 	return dmabuf->ops->mmap(dmabuf, vma);
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, "DMA_BUF");
diff --git a/include/trace/events/dma_buf.h b/include/trace/events/dma_buf.h
new file mode 100644
index 000000000000..81ee4d05979c
--- /dev/null
+++ b/include/trace/events/dma_buf.h
@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM dma_buf
+
+#if !defined(_TRACE_DMA_BUF_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_DMA_BUF_H
+
+#include <linux/dma-buf.h>
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(dma_buf,
+
+	TP_PROTO(struct dma_buf *dmabuf),
+
+	TP_ARGS(dmabuf),
+
+	TP_STRUCT__entry(
+		__string(exp_name, dmabuf->exp_name)
+		__field(size_t, size)
+		__field(ino_t, ino)
+	),
+
+	TP_fast_assign(
+		__assign_str(exp_name);
+		__entry->size = dmabuf->size;
+		__entry->ino = dmabuf->file->f_inode->i_ino;
+	),
+
+	TP_printk("exp_name=%s size=%zu ino=%lu",
+		  __get_str(exp_name),
+		  __entry->size,
+		  __entry->ino)
+);
+
+DECLARE_EVENT_CLASS(dma_buf_attach_dev,
+
+	TP_PROTO(struct dma_buf *dmabuf, struct dma_buf_attachment *attach, bool is_dynamic, struct device *dev),
+
+	TP_ARGS(dmabuf, attach, is_dynamic, dev),
+
+	TP_STRUCT__entry(
+		__string(dev_name, dev_name(dev))
+		__string(exp_name, dmabuf->exp_name)
+		__field(size_t, size)
+		__field(ino_t, ino)
+		__field(struct dma_buf_attachment *, attach)
+		__field(bool, is_dynamic)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev_name);
+		__assign_str(exp_name);
+		__entry->size = dmabuf->size;
+		__entry->ino = dmabuf->file->f_inode->i_ino;
+		__entry->is_dynamic = is_dynamic;
+		__entry->attach = attach;
+	),
+
+	TP_printk("exp_name=%s size=%zu ino=%lu attachment:%p is_dynamic=%d dev_name=%s",
+		  __get_str(exp_name),
+		  __entry->size,
+		  __entry->ino,
+		  __entry->attach,
+		  __entry->is_dynamic,
+		  __get_str(dev_name))
+);
+
+DECLARE_EVENT_CLASS(dma_buf_fd,
+
+	TP_PROTO(struct dma_buf *dmabuf, int fd),
+
+	TP_ARGS(dmabuf, fd),
+
+	TP_STRUCT__entry(
+		__string(exp_name, dmabuf->exp_name)
+		__field(size_t, size)
+		__field(ino_t, ino)
+		__field(int, fd)
+	),
+
+	TP_fast_assign(
+		__assign_str(exp_name);
+		__entry->size = dmabuf->size;
+		__entry->ino = dmabuf->file->f_inode->i_ino;
+		__entry->fd = fd;
+	),
+
+	TP_printk("exp_name=%s size=%zu ino=%lu fd=%d",
+		  __get_str(exp_name),
+		  __entry->size,
+		  __entry->ino,
+		  __entry->fd)
+);
+
+DEFINE_EVENT(dma_buf, dma_buf_export,
+
+	TP_PROTO(struct dma_buf *dmabuf),
+
+	TP_ARGS(dmabuf)
+);
+
+DEFINE_EVENT(dma_buf, dma_buf_mmap_internal,
+
+	TP_PROTO(struct dma_buf *dmabuf),
+
+	TP_ARGS(dmabuf)
+);
+
+DEFINE_EVENT(dma_buf, dma_buf_mmap,
+
+	TP_PROTO(struct dma_buf *dmabuf),
+
+	TP_ARGS(dmabuf)
+);
+
+DEFINE_EVENT(dma_buf, dma_buf_put,
+
+	TP_PROTO(struct dma_buf *dmabuf),
+
+	TP_ARGS(dmabuf)
+);
+
+DEFINE_EVENT(dma_buf_attach_dev, dma_buf_dynamic_attach,
+
+	TP_PROTO(struct dma_buf *dmabuf, struct dma_buf_attachment *attach, bool is_dynamic, struct device *dev),
+
+	TP_ARGS(dmabuf, attach, is_dynamic, dev)
+);
+
+DEFINE_EVENT(dma_buf_attach_dev, dma_buf_detach,
+
+	TP_PROTO(struct dma_buf *dmabuf, struct dma_buf_attachment *attach, bool is_dynamic, struct device *dev),
+
+	TP_ARGS(dmabuf, attach, is_dynamic, dev)
+);
+
+DEFINE_EVENT(dma_buf_fd, dma_buf_fd,
+
+	TP_PROTO(struct dma_buf *dmabuf, int fd),
+
+	TP_ARGS(dmabuf, fd)
+);
+
+DEFINE_EVENT(dma_buf_fd, dma_buf_get,
+
+	TP_PROTO(struct dma_buf *dmabuf, int fd),
+
+	TP_ARGS(dmabuf, fd)
+);
+
+#endif /* _TRACE_DMA_BUF_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
2.34.1

Re: [PATCH v6] dma-buf: add some tracepoints to debug.

[Christian König]

On 12/16/25 07:39, Xiang Gao wrote:
> From: gaoxiang17 <gaoxiang17@xiaomi.com>
> 
> Since we can only inspect dmabuf by iterating over process FDs or the
> dmabuf_list, we need to add our own tracepoints to track its status in
> real time in production.
> 
> For example:
>    binder:3016_1-3102    [006] ...1.   255.126521: dma_buf_export: exp_name=qcom,system size=12685312 ino=2738
>    binder:3016_1-3102    [006] ...1.   255.126528: dma_buf_fd: exp_name=qcom,system size=12685312 ino=2738 fd=8
>    binder:3016_1-3102    [006] ...1.   255.126642: dma_buf_mmap_internal: exp_name=qcom,system size=28672 ino=2739
>      kworker/6:1-86      [006] ...1.   255.127194: dma_buf_put: exp_name=qcom,system size=12685312 ino=2738
>     RenderThread-9293    [006] ...1.   316.618179: dma_buf_get: exp_name=qcom,system size=12771328 ino=2762 fd=176
>     RenderThread-9293    [006] ...1.   316.618195: dma_buf_dynamic_attach: exp_name=qcom,system size=12771328 ino=2762 attachment:ffffff880a18dd00 is_dynamic=0 dev_name=kgsl-3d0
>     RenderThread-9293    [006] ...1.   318.878220: dma_buf_detach: exp_name=qcom,system size=12771328 ino=2762 attachment:ffffff880a18dd00 is_dynamic=0 dev_name=kgsl-3d0
> 
> Signed-off-by: Xiang Gao <gaoxiang17@xiaomi.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

Going to push this to drm-misc-next today unless somebody has some last minute objections.

Regards,
Christian.

> ---
>  drivers/dma-buf/dma-buf.c      |  42 ++++++++-
>  include/trace/events/dma_buf.h | 154 +++++++++++++++++++++++++++++++++
>  2 files changed, 195 insertions(+), 1 deletion(-)
>  create mode 100644 include/trace/events/dma_buf.h
> 
> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
> index 2bcf9ceca997..831973de76c4 100644
> --- a/drivers/dma-buf/dma-buf.c
> +++ b/drivers/dma-buf/dma-buf.c
> @@ -35,6 +35,25 @@
>  
>  #include "dma-buf-sysfs-stats.h"
>  
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/dma_buf.h>
> +
> +/*
> + * dmabuf->name must be accessed with holding dmabuf->name_lock.
> + * we need to take the lock around the tracepoint call itself where
> + * it is called in the code.
> + *
> + * Note: FUNC##_enabled() is a static branch that will only
> + *       be set when the trace event is enabled.
> + */
> +#define DMA_BUF_TRACE(FUNC, ...)                  \
> +    do {                                          \
> +        if (FUNC##_enabled()) {                   \
> +            guard(spinlock)(&dmabuf->name_lock); \
> +            FUNC(__VA_ARGS__);                    \
> +        }                                         \
> +    } while (0)
> +
>  static inline int is_dma_buf_file(struct file *);
>  
>  static DEFINE_MUTEX(dmabuf_list_mutex);
> @@ -220,6 +239,8 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
>  	    dmabuf->size >> PAGE_SHIFT)
>  		return -EINVAL;
>  
> +	DMA_BUF_TRACE(trace_dma_buf_mmap_internal, dmabuf);
> +
>  	return dmabuf->ops->mmap(dmabuf, vma);
>  }
>  
> @@ -745,6 +766,8 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
>  
>  	__dma_buf_list_add(dmabuf);
>  
> +	DMA_BUF_TRACE(trace_dma_buf_export, dmabuf);
> +
>  	return dmabuf;
>  
>  err_dmabuf:
> @@ -779,6 +802,8 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags)
>  
>  	fd_install(fd, dmabuf->file);
>  
> +	DMA_BUF_TRACE(trace_dma_buf_fd, dmabuf, fd);
> +
>  	return fd;
>  }
>  EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF");
> @@ -794,6 +819,7 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF");
>  struct dma_buf *dma_buf_get(int fd)
>  {
>  	struct file *file;
> +	struct dma_buf *dmabuf;
>  
>  	file = fget(fd);
>  
> @@ -805,7 +831,11 @@ struct dma_buf *dma_buf_get(int fd)
>  		return ERR_PTR(-EINVAL);
>  	}
>  
> -	return file->private_data;
> +	dmabuf = file->private_data;
> +
> +	DMA_BUF_TRACE(trace_dma_buf_get, dmabuf, fd);
> +
> +	return dmabuf;
>  }
>  EXPORT_SYMBOL_NS_GPL(dma_buf_get, "DMA_BUF");
>  
> @@ -825,6 +855,8 @@ void dma_buf_put(struct dma_buf *dmabuf)
>  		return;
>  
>  	fput(dmabuf->file);
> +
> +	DMA_BUF_TRACE(trace_dma_buf_put, dmabuf);
>  }
>  EXPORT_SYMBOL_NS_GPL(dma_buf_put, "DMA_BUF");
>  
> @@ -979,6 +1011,9 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
>  	list_add(&attach->node, &dmabuf->attachments);
>  	dma_resv_unlock(dmabuf->resv);
>  
> +	DMA_BUF_TRACE(trace_dma_buf_dynamic_attach, dmabuf, attach,
> +		dma_buf_attachment_is_dynamic(attach), dev);
> +
>  	return attach;
>  
>  err_attach:
> @@ -1023,6 +1058,9 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
>  	if (dmabuf->ops->detach)
>  		dmabuf->ops->detach(dmabuf, attach);
>  
> +	DMA_BUF_TRACE(trace_dma_buf_detach, dmabuf, attach,
> +		dma_buf_attachment_is_dynamic(attach), attach->dev);
> +
>  	kfree(attach);
>  }
>  EXPORT_SYMBOL_NS_GPL(dma_buf_detach, "DMA_BUF");
> @@ -1488,6 +1526,8 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
>  	vma_set_file(vma, dmabuf->file);
>  	vma->vm_pgoff = pgoff;
>  
> +	DMA_BUF_TRACE(trace_dma_buf_mmap, dmabuf);
> +
>  	return dmabuf->ops->mmap(dmabuf, vma);
>  }
>  EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, "DMA_BUF");
> diff --git a/include/trace/events/dma_buf.h b/include/trace/events/dma_buf.h
> new file mode 100644
> index 000000000000..81ee4d05979c
> --- /dev/null
> +++ b/include/trace/events/dma_buf.h
> @@ -0,0 +1,154 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM dma_buf
> +
> +#if !defined(_TRACE_DMA_BUF_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_DMA_BUF_H
> +
> +#include <linux/dma-buf.h>
> +#include <linux/tracepoint.h>
> +
> +DECLARE_EVENT_CLASS(dma_buf,
> +
> +	TP_PROTO(struct dma_buf *dmabuf),
> +
> +	TP_ARGS(dmabuf),
> +
> +	TP_STRUCT__entry(
> +		__string(exp_name, dmabuf->exp_name)
> +		__field(size_t, size)
> +		__field(ino_t, ino)
> +	),
> +
> +	TP_fast_assign(
> +		__assign_str(exp_name);
> +		__entry->size = dmabuf->size;
> +		__entry->ino = dmabuf->file->f_inode->i_ino;
> +	),
> +
> +	TP_printk("exp_name=%s size=%zu ino=%lu",
> +		  __get_str(exp_name),
> +		  __entry->size,
> +		  __entry->ino)
> +);
> +
> +DECLARE_EVENT_CLASS(dma_buf_attach_dev,
> +
> +	TP_PROTO(struct dma_buf *dmabuf, struct dma_buf_attachment *attach, bool is_dynamic, struct device *dev),
> +
> +	TP_ARGS(dmabuf, attach, is_dynamic, dev),
> +
> +	TP_STRUCT__entry(
> +		__string(dev_name, dev_name(dev))
> +		__string(exp_name, dmabuf->exp_name)
> +		__field(size_t, size)
> +		__field(ino_t, ino)
> +		__field(struct dma_buf_attachment *, attach)
> +		__field(bool, is_dynamic)
> +	),
> +
> +	TP_fast_assign(
> +		__assign_str(dev_name);
> +		__assign_str(exp_name);
> +		__entry->size = dmabuf->size;
> +		__entry->ino = dmabuf->file->f_inode->i_ino;
> +		__entry->is_dynamic = is_dynamic;
> +		__entry->attach = attach;
> +	),
> +
> +	TP_printk("exp_name=%s size=%zu ino=%lu attachment:%p is_dynamic=%d dev_name=%s",
> +		  __get_str(exp_name),
> +		  __entry->size,
> +		  __entry->ino,
> +		  __entry->attach,
> +		  __entry->is_dynamic,
> +		  __get_str(dev_name))
> +);
> +
> +DECLARE_EVENT_CLASS(dma_buf_fd,
> +
> +	TP_PROTO(struct dma_buf *dmabuf, int fd),
> +
> +	TP_ARGS(dmabuf, fd),
> +
> +	TP_STRUCT__entry(
> +		__string(exp_name, dmabuf->exp_name)
> +		__field(size_t, size)
> +		__field(ino_t, ino)
> +		__field(int, fd)
> +	),
> +
> +	TP_fast_assign(
> +		__assign_str(exp_name);
> +		__entry->size = dmabuf->size;
> +		__entry->ino = dmabuf->file->f_inode->i_ino;
> +		__entry->fd = fd;
> +	),
> +
> +	TP_printk("exp_name=%s size=%zu ino=%lu fd=%d",
> +		  __get_str(exp_name),
> +		  __entry->size,
> +		  __entry->ino,
> +		  __entry->fd)
> +);
> +
> +DEFINE_EVENT(dma_buf, dma_buf_export,
> +
> +	TP_PROTO(struct dma_buf *dmabuf),
> +
> +	TP_ARGS(dmabuf)
> +);
> +
> +DEFINE_EVENT(dma_buf, dma_buf_mmap_internal,
> +
> +	TP_PROTO(struct dma_buf *dmabuf),
> +
> +	TP_ARGS(dmabuf)
> +);
> +
> +DEFINE_EVENT(dma_buf, dma_buf_mmap,
> +
> +	TP_PROTO(struct dma_buf *dmabuf),
> +
> +	TP_ARGS(dmabuf)
> +);
> +
> +DEFINE_EVENT(dma_buf, dma_buf_put,
> +
> +	TP_PROTO(struct dma_buf *dmabuf),
> +
> +	TP_ARGS(dmabuf)
> +);
> +
> +DEFINE_EVENT(dma_buf_attach_dev, dma_buf_dynamic_attach,
> +
> +	TP_PROTO(struct dma_buf *dmabuf, struct dma_buf_attachment *attach, bool is_dynamic, struct device *dev),
> +
> +	TP_ARGS(dmabuf, attach, is_dynamic, dev)
> +);
> +
> +DEFINE_EVENT(dma_buf_attach_dev, dma_buf_detach,
> +
> +	TP_PROTO(struct dma_buf *dmabuf, struct dma_buf_attachment *attach, bool is_dynamic, struct device *dev),
> +
> +	TP_ARGS(dmabuf, attach, is_dynamic, dev)
> +);
> +
> +DEFINE_EVENT(dma_buf_fd, dma_buf_fd,
> +
> +	TP_PROTO(struct dma_buf *dmabuf, int fd),
> +
> +	TP_ARGS(dmabuf, fd)
> +);
> +
> +DEFINE_EVENT(dma_buf_fd, dma_buf_get,
> +
> +	TP_PROTO(struct dma_buf *dmabuf, int fd),
> +
> +	TP_ARGS(dmabuf, fd)
> +);
> +
> +#endif /* _TRACE_DMA_BUF_H */
> +
> +/* This part must be outside protection */
> +#include <trace/define_trace.h>

Re: [PATCH v6] dma-buf: add some tracepoints to debug.

[Barry Song]

On Tue, Dec 16, 2025 at 4:44 PM Christian König
<christian.koenig@amd.com> wrote:
>
> On 12/16/25 07:39, Xiang Gao wrote:
> > From: gaoxiang17 <gaoxiang17@xiaomi.com>
> >
> > Since we can only inspect dmabuf by iterating over process FDs or the
> > dmabuf_list, we need to add our own tracepoints to track its status in
> > real time in production.
> >
> > For example:
> >    binder:3016_1-3102    [006] ...1.   255.126521: dma_buf_export: exp_name=qcom,system size=12685312 ino=2738
> >    binder:3016_1-3102    [006] ...1.   255.126528: dma_buf_fd: exp_name=qcom,system size=12685312 ino=2738 fd=8
> >    binder:3016_1-3102    [006] ...1.   255.126642: dma_buf_mmap_internal: exp_name=qcom,system size=28672 ino=2739
> >      kworker/6:1-86      [006] ...1.   255.127194: dma_buf_put: exp_name=qcom,system size=12685312 ino=2738
> >     RenderThread-9293    [006] ...1.   316.618179: dma_buf_get: exp_name=qcom,system size=12771328 ino=2762 fd=176
> >     RenderThread-9293    [006] ...1.   316.618195: dma_buf_dynamic_attach: exp_name=qcom,system size=12771328 ino=2762 attachment:ffffff880a18dd00 is_dynamic=0 dev_name=kgsl-3d0
> >     RenderThread-9293    [006] ...1.   318.878220: dma_buf_detach: exp_name=qcom,system size=12771328 ino=2762 attachment:ffffff880a18dd00 is_dynamic=0 dev_name=kgsl-3d0
> >
> > Signed-off-by: Xiang Gao <gaoxiang17@xiaomi.com>
>
> Reviewed-by: Christian König <christian.koenig@amd.com>
>
> Going to push this to drm-misc-next today unless somebody has some last minute objections.

No objection, but I would strongly suggest Xiang include a
diff description next time, after the changelog for each new
version.

I recall clearly commenting on both changelog refinement and
the DMA_BUF_TRACE() macro [1]. It would be better to mention
similar things for each new version next time :-)

[1] https://lore.kernel.org/lkml/CAGsJ_4y0zc_nh2q=w4uR04vtveCf6L7+hgafznHuL8ByWbyNOQ@mail.gmail.com/

Thanks
Barry

Re: 答复: [External Mail]Re: [PATCH v6] dma-buf: add some tracepoints to debug.

[Christian König]

I have to take that back, the automated checkers have nit picks on this patch:

/home/ckoenig/Downloads/[PATCH v6] dma-buf: add some tracepoints to debug. - Xiang Gao <gxxa03070307@gmail.com> - 2025-12-16 0739.eml:308: trailing whitespace.
/* SPDX-License-Identifier: GPL-2.0 */
/home/ckoenig/Downloads/[PATCH v6] dma-buf: add some tracepoints to debug. - Xiang Gao <gxxa03070307@gmail.com> - 2025-12-16 0739.eml:309: trailing whitespace.
#undef TRACE_SYSTEM
/home/ckoenig/Downloads/[PATCH v6] dma-buf: add some tracepoints to debug. - Xiang Gao <gxxa03070307@gmail.com> - 2025-12-16 0739.eml:310: trailing whitespace.
#define TRACE_SYSTEM dma_buf
/home/ckoenig/Downloads/[PATCH v6] dma-buf: add some tracepoints to debug. - Xiang Gao <gxxa03070307@gmail.com> - 2025-12-16 0739.eml:311: trailing whitespace.

/home/ckoenig/Downloads/[PATCH v6] dma-buf: add some tracepoints to debug. - Xiang Gao <gxxa03070307@gmail.com> - 2025-12-16 0739.eml:312: trailing whitespace.
#if !defined(_TRACE_DMA_BUF_H) || defined(TRACE_HEADER_MULTI_READ)

Additional to that the patch doesn't seems to be based against drm-misc-next:

error: patch failed: drivers/dma-buf/dma-buf.c:35
error: drivers/dma-buf/dma-buf.c: patch does not apply

So please fix the whitespace issues, rebase and send out again. I should be able to apply it tomorrow then.

Regards,
Christian.

On 12/16/25 14:12, 高翔 wrote:
> thanks.
> 
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> *发件人:* Christian König <christian.koenig@amd.com>
> *发送时间:* 2025年12月16日 16:43:26
> *收件人:* Xiang Gao; sumit.semwal@linaro.org; rostedt@goodmis.org; mhiramat@kernel.org
> *抄送:* linux-media@vger.kernel.org; dri-devel@lists.freedesktop.org; linux-kernel@vger.kernel.org; mathieu.desnoyers@efficios.com; dhowells@redhat.com; kuba@kernel.org; brauner@kernel.org; akpm@linux-foundation.org; linux-trace-kernel@vger.kernel.org; 高翔
> *主题:* [External Mail]Re: [PATCH v6] dma-buf: add some tracepoints to debug.
>  
> [外部邮件] 此邮件来源于小米公司外部，请谨慎处理。若对邮件安全性存疑，请将邮件转发给misec@xiaomi.com进行反馈
> 
> On 12/16/25 07:39, Xiang Gao wrote:
>> From: gaoxiang17 <gaoxiang17@xiaomi.com>
>>
>> Since we can only inspect dmabuf by iterating over process FDs or the
>> dmabuf_list, we need to add our own tracepoints to track its status in
>> real time in production.
>>
>> For example:
>>    binder:3016_1-3102    [006] ...1.   255.126521: dma_buf_export: exp_name=qcom,system size=12685312 ino=2738
>>    binder:3016_1-3102    [006] ...1.   255.126528: dma_buf_fd: exp_name=qcom,system size=12685312 ino=2738 fd=8
>>    binder:3016_1-3102    [006] ...1.   255.126642: dma_buf_mmap_internal: exp_name=qcom,system size=28672 ino=2739
>>      kworker/6:1-86      [006] ...1.   255.127194: dma_buf_put: exp_name=qcom,system size=12685312 ino=2738
>>     RenderThread-9293    [006] ...1.   316.618179: dma_buf_get: exp_name=qcom,system size=12771328 ino=2762 fd=176
>>     RenderThread-9293    [006] ...1.   316.618195: dma_buf_dynamic_attach: exp_name=qcom,system size=12771328 ino=2762 attachment:ffffff880a18dd00 is_dynamic=0 dev_name=kgsl-3d0
>>     RenderThread-9293    [006] ...1.   318.878220: dma_buf_detach: exp_name=qcom,system size=12771328 ino=2762 attachment:ffffff880a18dd00 is_dynamic=0 dev_name=kgsl-3d0
>>
>> Signed-off-by: Xiang Gao <gaoxiang17@xiaomi.com>
> 
> Reviewed-by: Christian König <christian.koenig@amd.com>
> 
> Going to push this to drm-misc-next today unless somebody has some last minute objections.
> 
> Regards,
> Christian.
> 
>> ---
>>  drivers/dma-buf/dma-buf.c      |  42 ++++++++-
>>  include/trace/events/dma_buf.h | 154 +++++++++++++++++++++++++++++++++
>>  2 files changed, 195 insertions(+), 1 deletion(-)
>>  create mode 100644 include/trace/events/dma_buf.h
>>
>> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
>> index 2bcf9ceca997..831973de76c4 100644
>> --- a/drivers/dma-buf/dma-buf.c
>> +++ b/drivers/dma-buf/dma-buf.c
>> @@ -35,6 +35,25 @@
>>
>>  #include "dma-buf-sysfs-stats.h"
>>
>> +#define CREATE_TRACE_POINTS
>> +#include <trace/events/dma_buf.h>
>> +
>> +/*
>> + * dmabuf->name must be accessed with holding dmabuf->name_lock.
>> + * we need to take the lock around the tracepoint call itself where
>> + * it is called in the code.
>> + *
>> + * Note: FUNC##_enabled() is a static branch that will only
>> + *       be set when the trace event is enabled.
>> + */
>> +#define DMA_BUF_TRACE(FUNC, ...)                  \
>> +    do {                                          \
>> +        if (FUNC##_enabled()) {                   \
>> +            guard(spinlock)(&dmabuf->name_lock); \
>> +            FUNC(__VA_ARGS__);                    \
>> +        }                                         \
>> +    } while (0)
>> +
>>  static inline int is_dma_buf_file(struct file *);
>>
>>  static DEFINE_MUTEX(dmabuf_list_mutex);
>> @@ -220,6 +239,8 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
>>           dmabuf->size >> PAGE_SHIFT)
>>               return -EINVAL;
>>
>> +     DMA_BUF_TRACE(trace_dma_buf_mmap_internal, dmabuf);
>> +
>>       return dmabuf->ops->mmap(dmabuf, vma);
>>  }
>>
>> @@ -745,6 +766,8 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
>>
>>       __dma_buf_list_add(dmabuf);
>>
>> +     DMA_BUF_TRACE(trace_dma_buf_export, dmabuf);
>> +
>>       return dmabuf;
>>
>>  err_dmabuf:
>> @@ -779,6 +802,8 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags)
>>
>>       fd_install(fd, dmabuf->file);
>>
>> +     DMA_BUF_TRACE(trace_dma_buf_fd, dmabuf, fd);
>> +
>>       return fd;
>>  }
>>  EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF");
>> @@ -794,6 +819,7 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF");
>>  struct dma_buf *dma_buf_get(int fd)
>>  {
>>       struct file *file;
>> +     struct dma_buf *dmabuf;
>>
>>       file = fget(fd);
>>
>> @@ -805,7 +831,11 @@ struct dma_buf *dma_buf_get(int fd)
>>               return ERR_PTR(-EINVAL);
>>       }
>>
>> -     return file->private_data;
>> +     dmabuf = file->private_data;
>> +
>> +     DMA_BUF_TRACE(trace_dma_buf_get, dmabuf, fd);
>> +
>> +     return dmabuf;
>>  }
>>  EXPORT_SYMBOL_NS_GPL(dma_buf_get, "DMA_BUF");
>>
>> @@ -825,6 +855,8 @@ void dma_buf_put(struct dma_buf *dmabuf)
>>               return;
>>
>>       fput(dmabuf->file);
>> +
>> +     DMA_BUF_TRACE(trace_dma_buf_put, dmabuf);
>>  }
>>  EXPORT_SYMBOL_NS_GPL(dma_buf_put, "DMA_BUF");
>>
>> @@ -979,6 +1011,9 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
>>       list_add(&attach->node, &dmabuf->attachments);
>>       dma_resv_unlock(dmabuf->resv);
>>
>> +     DMA_BUF_TRACE(trace_dma_buf_dynamic_attach, dmabuf, attach,
>> +             dma_buf_attachment_is_dynamic(attach), dev);
>> +
>>       return attach;
>>
>>  err_attach:
>> @@ -1023,6 +1058,9 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
>>       if (dmabuf->ops->detach)
>>               dmabuf->ops->detach(dmabuf, attach);
>>
>> +     DMA_BUF_TRACE(trace_dma_buf_detach, dmabuf, attach,
>> +             dma_buf_attachment_is_dynamic(attach), attach->dev);
>> +
>>       kfree(attach);
>>  }
>>  EXPORT_SYMBOL_NS_GPL(dma_buf_detach, "DMA_BUF");
>> @@ -1488,6 +1526,8 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
>>       vma_set_file(vma, dmabuf->file);
>>       vma->vm_pgoff = pgoff;
>>
>> +     DMA_BUF_TRACE(trace_dma_buf_mmap, dmabuf);
>> +
>>       return dmabuf->ops->mmap(dmabuf, vma);
>>  }
>>  EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, "DMA_BUF");
>> diff --git a/include/trace/events/dma_buf.h b/include/trace/events/dma_buf.h
>> new file mode 100644
>> index 000000000000..81ee4d05979c
>> --- /dev/null
>> +++ b/include/trace/events/dma_buf.h
>> @@ -0,0 +1,154 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#undef TRACE_SYSTEM
>> +#define TRACE_SYSTEM dma_buf
>> +
>> +#if !defined(_TRACE_DMA_BUF_H) || defined(TRACE_HEADER_MULTI_READ)
>> +#define _TRACE_DMA_BUF_H
>> +
>> +#include <linux/dma-buf.h>
>> +#include <linux/tracepoint.h>
>> +
>> +DECLARE_EVENT_CLASS(dma_buf,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf),
>> +
>> +     TP_ARGS(dmabuf),
>> +
>> +     TP_STRUCT__entry(
>> +             __string(exp_name, dmabuf->exp_name)
>> +             __field(size_t, size)
>> +             __field(ino_t, ino)
>> +     ),
>> +
>> +     TP_fast_assign(
>> +             __assign_str(exp_name);
>> +             __entry->size = dmabuf->size;
>> +             __entry->ino = dmabuf->file->f_inode->i_ino;
>> +     ),
>> +
>> +     TP_printk("exp_name=%s size=%zu ino=%lu",
>> +               __get_str(exp_name),
>> +               __entry->size,
>> +               __entry->ino)
>> +);
>> +
>> +DECLARE_EVENT_CLASS(dma_buf_attach_dev,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf, struct dma_buf_attachment *attach, bool is_dynamic, struct device *dev),
>> +
>> +     TP_ARGS(dmabuf, attach, is_dynamic, dev),
>> +
>> +     TP_STRUCT__entry(
>> +             __string(dev_name, dev_name(dev))
>> +             __string(exp_name, dmabuf->exp_name)
>> +             __field(size_t, size)
>> +             __field(ino_t, ino)
>> +             __field(struct dma_buf_attachment *, attach)
>> +             __field(bool, is_dynamic)
>> +     ),
>> +
>> +     TP_fast_assign(
>> +             __assign_str(dev_name);
>> +             __assign_str(exp_name);
>> +             __entry->size = dmabuf->size;
>> +             __entry->ino = dmabuf->file->f_inode->i_ino;
>> +             __entry->is_dynamic = is_dynamic;
>> +             __entry->attach = attach;
>> +     ),
>> +
>> +     TP_printk("exp_name=%s size=%zu ino=%lu attachment:%p is_dynamic=%d dev_name=%s",
>> +               __get_str(exp_name),
>> +               __entry->size,
>> +               __entry->ino,
>> +               __entry->attach,
>> +               __entry->is_dynamic,
>> +               __get_str(dev_name))
>> +);
>> +
>> +DECLARE_EVENT_CLASS(dma_buf_fd,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf, int fd),
>> +
>> +     TP_ARGS(dmabuf, fd),
>> +
>> +     TP_STRUCT__entry(
>> +             __string(exp_name, dmabuf->exp_name)
>> +             __field(size_t, size)
>> +             __field(ino_t, ino)
>> +             __field(int, fd)
>> +     ),
>> +
>> +     TP_fast_assign(
>> +             __assign_str(exp_name);
>> +             __entry->size = dmabuf->size;
>> +             __entry->ino = dmabuf->file->f_inode->i_ino;
>> +             __entry->fd = fd;
>> +     ),
>> +
>> +     TP_printk("exp_name=%s size=%zu ino=%lu fd=%d",
>> +               __get_str(exp_name),
>> +               __entry->size,
>> +               __entry->ino,
>> +               __entry->fd)
>> +);
>> +
>> +DEFINE_EVENT(dma_buf, dma_buf_export,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf),
>> +
>> +     TP_ARGS(dmabuf)
>> +);
>> +
>> +DEFINE_EVENT(dma_buf, dma_buf_mmap_internal,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf),
>> +
>> +     TP_ARGS(dmabuf)
>> +);
>> +
>> +DEFINE_EVENT(dma_buf, dma_buf_mmap,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf),
>> +
>> +     TP_ARGS(dmabuf)
>> +);
>> +
>> +DEFINE_EVENT(dma_buf, dma_buf_put,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf),
>> +
>> +     TP_ARGS(dmabuf)
>> +);
>> +
>> +DEFINE_EVENT(dma_buf_attach_dev, dma_buf_dynamic_attach,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf, struct dma_buf_attachment *attach, bool is_dynamic, struct device *dev),
>> +
>> +     TP_ARGS(dmabuf, attach, is_dynamic, dev)
>> +);
>> +
>> +DEFINE_EVENT(dma_buf_attach_dev, dma_buf_detach,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf, struct dma_buf_attachment *attach, bool is_dynamic, struct device *dev),
>> +
>> +     TP_ARGS(dmabuf, attach, is_dynamic, dev)
>> +);
>> +
>> +DEFINE_EVENT(dma_buf_fd, dma_buf_fd,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf, int fd),
>> +
>> +     TP_ARGS(dmabuf, fd)
>> +);
>> +
>> +DEFINE_EVENT(dma_buf_fd, dma_buf_get,
>> +
>> +     TP_PROTO(struct dma_buf *dmabuf, int fd),
>> +
>> +     TP_ARGS(dmabuf, fd)
>> +);
>> +
>> +#endif /* _TRACE_DMA_BUF_H */
>> +
>> +/* This part must be outside protection */
>> +#include <trace/define_trace.h>
>