drivers/dma-buf/dma-buf.c | 42 ++++++++- include/trace/events/dma_buf.h | 157 +++++++++++++++++++++++++++++++++ 2 files changed, 198 insertions(+), 1 deletion(-) create mode 100644 include/trace/events/dma_buf.h
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 | 157 +++++++++++++++++++++++++++++++++
2 files changed, 198 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..ce39bc19e13f 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..35f8140095f4
--- /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)
+);
+
+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>
--
2.34.1On Wed, 17 Dec 2025 18:51:32 +0800
Xiang Gao <gxxa03070307@gmail.com> 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>
> ---
> drivers/dma-buf/dma-buf.c | 42 ++++++++-
> include/trace/events/dma_buf.h | 157 +++++++++++++++++++++++++++++++++
> 2 files changed, 198 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..ce39bc19e13f 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.
> + */
Much better.
> +#define DMA_BUF_TRACE(FUNC, ...) \
> + do { \
> + if (FUNC##_enabled()) { \
> + guard(spinlock)(&dmabuf->name_lock); \
> + FUNC(__VA_ARGS__); \
> + } \
Hmm, I wonder if we should also add:
} else if (IS_ENABLED(CONFIG_LOCKDEP)) { \
/* Expose this lock when lockdep is enabled */ \
guard(spinlock)(&dmabuf->name_lock); \
}
This way, if there is any issue taking the lock, lockdep will flag it
without having to enable the tracepoint.
When LOCKDEP is not configured, the compiler should remove that block.
> + } while (0)
> +
> static inline int is_dma_buf_file(struct file *);
>
>
> --- /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)
> +);
For the rest of the patch, from a tracing point of view:
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-- Steve
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