Re: [PATCH v10] dma-buf: add some tracepoints to debug.

 drivers/dma-buf/dma-buf.c      |  49 +++++++++-
 include/trace/events/dma_buf.h | 157 +++++++++++++++++++++++++++++++++
 2 files changed, 204 insertions(+), 2 deletions(-)
 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 edaa9e4ee4ae..5e6f65cd0306 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c

@@ -35,6 +35,26 @@
 
 #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 {											\
+		/* Always expose lock if lockdep is enabled */ 	\
+		if (IS_ENABLED(CONFIG_LOCKDEP) || 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 +240,8 @@ 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 +767,8 @@ 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:

@@ -768,10 +792,16 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_export, "DMA_BUF");
  */
 int dma_buf_fd(struct dma_buf *dmabuf, int flags)
 {
+	int fd;
+
 	if (!dmabuf || !dmabuf->file)
 		return -EINVAL;
 
-	return FD_ADD(flags, dmabuf->file);
+	fd = FD_ADD(flags, dmabuf->file);
+	if (fd >= 0)
+		DMA_BUF_TRACE(trace_dma_buf_fd, dmabuf, fd);

diff --git a/include/trace/events/dma_buf.h b/include/trace/events/dma_buf.h
new file mode 100644
index 000000000000..2c9ba8533467
--- /dev/null
+++ b/include/trace/events/dma_buf.h

@@ -0,0 +1,157 @@
+/* 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)
+);
+