drivers/dma-buf/dma-buf.c | 48 +++++++++- include/trace/events/dma_buf.h | 160 +++++++++++++++++++++++++++++++++ 2 files changed, 207 insertions(+), 1 deletion(-) create mode 100644 include/trace/events/dma_buf.h
From: gaoxiang17 <gaoxiang17@xiaomi.com>
I want to track the status of dmabuf in real time in the production environment.
But now we can only check it by traversing the fd in the process or dmabuf_list.
For example:
binder:3031_4-18348 [005] ...1. 545.568275: dma_buf_export: exp_name=qcom,system name=(null) size=217088 ino=2750
binder:3031_4-18348 [005] ...1. 545.568284: dma_buf_fd: exp_name=qcom,system name=(null) size=217088 ino=2750 fd=8
binder:3031_4-18348 [005] ...1. 545.568399: dma_buf_mmap_internal: exp_name=qcom,system name=qcom,system size=28672 ino=2751
kworker/5:1-130 [005] ...1. 545.570193: dma_buf_put: exp_name=qcom,system name=ab size=28672 ino=2751
RenderThread-18891 [005] ...1. 545.602994: dma_buf_get: exp_name=qcom,system name=ab size=217088 ino=2750 fd=1087
RenderThread-9409 [000] .n.1. 545.745004: dma_buf_dynamic_attach: exp_name=qcom,system name=ab size=217088 ino=2750 is_dynamic=0 dev_name=kgsl-3d0
RenderThread-9409 [005] ...1. 545.747802: dma_buf_detach: exp_name=qcom,system name=bq size=12771328 ino=2764 is_dynamic=0 dev_name=kgsl-3d0
Signed-off-by: Xiang Gao <gaoxiang17@xiaomi.com>
---
drivers/dma-buf/dma-buf.c | 48 +++++++++-
include/trace/events/dma_buf.h | 160 +++++++++++++++++++++++++++++++++
2 files changed, 207 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..6e04e12f149e 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -35,6 +35,9 @@
#include "dma-buf-sysfs-stats.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/dma_buf.h>
+
static inline int is_dma_buf_file(struct file *);
static DEFINE_MUTEX(dmabuf_list_mutex);
@@ -220,6 +223,11 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
dmabuf->size >> PAGE_SHIFT)
return -EINVAL;
+ if (trace_dma_buf_mmap_internal_enabled()) {
+ guard(spinlock)(&dmabuf->name_lock);
+ trace_dma_buf_mmap_internal(dmabuf);
+ }
+
return dmabuf->ops->mmap(dmabuf, vma);
}
@@ -745,6 +753,11 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
__dma_buf_list_add(dmabuf);
+ if (trace_dma_buf_export_enabled()) {
+ guard(spinlock)(&dmabuf->name_lock);
+ trace_dma_buf_export(dmabuf);
+ }
+
return dmabuf;
err_dmabuf:
@@ -779,6 +792,11 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags)
fd_install(fd, dmabuf->file);
+ if (trace_dma_buf_fd_enabled()) {
+ guard(spinlock)(&dmabuf->name_lock);
+ trace_dma_buf_fd(dmabuf, fd);
+ }
+
return fd;
}
EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF");
@@ -794,6 +812,7 @@ 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 +824,14 @@ struct dma_buf *dma_buf_get(int fd)
return ERR_PTR(-EINVAL);
}
- return file->private_data;
+ dmabuf = file->private_data;
+
+ if (trace_dma_buf_get_enabled()) {
+ guard(spinlock)(&dmabuf->name_lock);
+ trace_dma_buf_get(dmabuf, fd);
+ }
+
+ return dmabuf;
}
EXPORT_SYMBOL_NS_GPL(dma_buf_get, "DMA_BUF");
@@ -825,6 +851,11 @@ void dma_buf_put(struct dma_buf *dmabuf)
return;
fput(dmabuf->file);
+
+ if (trace_dma_buf_put_enabled()) {
+ guard(spinlock)(&dmabuf->name_lock);
+ trace_dma_buf_put(dmabuf);
+ }
}
EXPORT_SYMBOL_NS_GPL(dma_buf_put, "DMA_BUF");
@@ -979,6 +1010,11 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
list_add(&attach->node, &dmabuf->attachments);
dma_resv_unlock(dmabuf->resv);
+ if (trace_dma_buf_dynamic_attach_enabled()) {
+ guard(spinlock)(&dmabuf->name_lock);
+ trace_dma_buf_dynamic_attach(dmabuf, dma_buf_attachment_is_dynamic(attach), dev);
+ }
+
return attach;
err_attach:
@@ -1023,6 +1059,11 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
if (dmabuf->ops->detach)
dmabuf->ops->detach(dmabuf, attach);
+ if (trace_dma_buf_detach_enabled()) {
+ guard(spinlock)(&dmabuf->name_lock);
+ trace_dma_buf_detach(dmabuf, dma_buf_attachment_is_dynamic(attach), attach->dev);
+ }
+
kfree(attach);
}
EXPORT_SYMBOL_NS_GPL(dma_buf_detach, "DMA_BUF");
@@ -1488,6 +1529,11 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
vma_set_file(vma, dmabuf->file);
vma->vm_pgoff = pgoff;
+ if (trace_dma_buf_mmap_enabled()) {
+ guard(spinlock)(&dmabuf->name_lock);
+ 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..f4b6ba5241fa
--- /dev/null
+++ b/include/trace/events/dma_buf.h
@@ -0,0 +1,160 @@
+/* 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)
+ __string(name, dmabuf->name)
+ __field(size_t, size)
+ __field(ino_t, ino)
+ ),
+
+ TP_fast_assign(
+ __assign_str(exp_name);
+ __assign_str(name);
+ __entry->size = dmabuf->size;
+ __entry->ino = dmabuf->file->f_inode->i_ino;
+ ),
+
+ TP_printk("exp_name=%s name=%s size=%zu ino=%lu",
+ __get_str(exp_name),
+ __get_str(name),
+ __entry->size,
+ __entry->ino)
+);
+
+DECLARE_EVENT_CLASS(dma_buf_attach_dev,
+
+ TP_PROTO(struct dma_buf *dmabuf, bool is_dynamic, struct device *dev),
+
+ TP_ARGS(dmabuf, is_dynamic, dev),
+
+ TP_STRUCT__entry(
+ __string(dev_name, dev_name(dev))
+ __string(exp_name, dmabuf->exp_name)
+ __string(name, dmabuf->name)
+ __field(size_t, size)
+ __field(ino_t, ino)
+ __field(bool, is_dynamic)
+ ),
+
+ TP_fast_assign(
+ __assign_str(dev_name);
+ __assign_str(exp_name);
+ __assign_str(name);
+ __entry->size = dmabuf->size;
+ __entry->ino = dmabuf->file->f_inode->i_ino;
+ __entry->is_dynamic = is_dynamic;
+ ),
+
+ TP_printk("exp_name=%s name=%s size=%zu ino=%lu is_dynamic=%d dev_name=%s",
+ __get_str(exp_name),
+ __get_str(name),
+ __entry->size,
+ __entry->ino,
+ __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)
+ __string(name, dmabuf->name)
+ __field(size_t, size)
+ __field(ino_t, ino)
+ __field(int, fd)
+ ),
+
+ TP_fast_assign(
+ __assign_str(exp_name);
+ __assign_str(name);
+ __entry->size = dmabuf->size;
+ __entry->ino = dmabuf->file->f_inode->i_ino;
+ __entry->fd = fd;
+ ),
+
+ TP_printk("exp_name=%s name=%s size=%zu ino=%lu fd=%d",
+ __get_str(exp_name),
+ __get_str(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, bool is_dynamic, struct device *dev),
+
+ TP_ARGS(dmabuf, is_dynamic, dev)
+);
+
+DEFINE_EVENT(dma_buf_attach_dev, dma_buf_detach,
+
+ TP_PROTO(struct dma_buf *dmabuf, bool is_dynamic, struct device *dev),
+
+ TP_ARGS(dmabuf, 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 Fri, Nov 28, 2025 at 4:53 PM Xiang Gao <gxxa03070307@gmail.com> wrote:
>
> From: gaoxiang17 <gaoxiang17@xiaomi.com>
>
> I want to track the status of dmabuf in real time in the production environment.
> But now we can only check it by traversing the fd in the process or dmabuf_list.
might be:
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:3031_4-18348 [005] ...1. 545.568275: dma_buf_export: exp_name=qcom,system name=(null) size=217088 ino=2750
> binder:3031_4-18348 [005] ...1. 545.568284: dma_buf_fd: exp_name=qcom,system name=(null) size=217088 ino=2750 fd=8
> binder:3031_4-18348 [005] ...1. 545.568399: dma_buf_mmap_internal: exp_name=qcom,system name=qcom,system size=28672 ino=2751
> kworker/5:1-130 [005] ...1. 545.570193: dma_buf_put: exp_name=qcom,system name=ab size=28672 ino=2751
> RenderThread-18891 [005] ...1. 545.602994: dma_buf_get: exp_name=qcom,system name=ab size=217088 ino=2750 fd=1087
> RenderThread-9409 [000] .n.1. 545.745004: dma_buf_dynamic_attach: exp_name=qcom,system name=ab size=217088 ino=2750 is_dynamic=0 dev_name=kgsl-3d0
> RenderThread-9409 [005] ...1. 545.747802: dma_buf_detach: exp_name=qcom,system name=bq size=12771328 ino=2764 is_dynamic=0 dev_name=kgsl-3d0
>
> Signed-off-by: Xiang Gao <gaoxiang17@xiaomi.com>
> ---
> drivers/dma-buf/dma-buf.c | 48 +++++++++-
> include/trace/events/dma_buf.h | 160 +++++++++++++++++++++++++++++++++
> 2 files changed, 207 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..6e04e12f149e 100644
> --- a/drivers/dma-buf/dma-buf.c
> +++ b/drivers/dma-buf/dma-buf.c
> @@ -35,6 +35,9 @@
>
> #include "dma-buf-sysfs-stats.h"
>
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/dma_buf.h>
> +
> static inline int is_dma_buf_file(struct file *);
>
> static DEFINE_MUTEX(dmabuf_list_mutex);
> @@ -220,6 +223,11 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
> dmabuf->size >> PAGE_SHIFT)
> return -EINVAL;
>
> + if (trace_dma_buf_mmap_internal_enabled()) {
> + guard(spinlock)(&dmabuf->name_lock);
> + trace_dma_buf_mmap_internal(dmabuf);
> + }
> +
> return dmabuf->ops->mmap(dmabuf, vma);
> }
>
> @@ -745,6 +753,11 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
>
> __dma_buf_list_add(dmabuf);
>
> + if (trace_dma_buf_export_enabled()) {
> + guard(spinlock)(&dmabuf->name_lock);
> + trace_dma_buf_export(dmabuf);
> + }
> +
perhaps a macro similar to the one below
#define DMA_BUF_TRACE(FUNC, ...) \
do { \
if (FUNC##_enabled()) { \
guard(spinlock)(&dmabuf->name_lock); \
FUNC(__VA_ARGS__); \
} \
} while (0)
This would help us avoid duplicating a lot of code.
could be:
DMA_BUF_TRACE(trace_dma_buf_put, dmabuf);
DMA_BUF_TRACE(trace_dma_buf_attach, dmabuf, dev);
?
On 11/28/25 10:31, Barry Song wrote:
> On Fri, Nov 28, 2025 at 4:53 PM Xiang Gao <gxxa03070307@gmail.com> wrote:
>>
>> From: gaoxiang17 <gaoxiang17@xiaomi.com>
>>
>> I want to track the status of dmabuf in real time in the production environment.
>> But now we can only check it by traversing the fd in the process or dmabuf_list.
>
> might be:
>
> 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:3031_4-18348 [005] ...1. 545.568275: dma_buf_export: exp_name=qcom,system name=(null) size=217088 ino=2750
>> binder:3031_4-18348 [005] ...1. 545.568284: dma_buf_fd: exp_name=qcom,system name=(null) size=217088 ino=2750 fd=8
>> binder:3031_4-18348 [005] ...1. 545.568399: dma_buf_mmap_internal: exp_name=qcom,system name=qcom,system size=28672 ino=2751
>> kworker/5:1-130 [005] ...1. 545.570193: dma_buf_put: exp_name=qcom,system name=ab size=28672 ino=2751
>> RenderThread-18891 [005] ...1. 545.602994: dma_buf_get: exp_name=qcom,system name=ab size=217088 ino=2750 fd=1087
>> RenderThread-9409 [000] .n.1. 545.745004: dma_buf_dynamic_attach: exp_name=qcom,system name=ab size=217088 ino=2750 is_dynamic=0 dev_name=kgsl-3d0
>> RenderThread-9409 [005] ...1. 545.747802: dma_buf_detach: exp_name=qcom,system name=bq size=12771328 ino=2764 is_dynamic=0 dev_name=kgsl-3d0
>>
>> Signed-off-by: Xiang Gao <gaoxiang17@xiaomi.com>
>> ---
>> drivers/dma-buf/dma-buf.c | 48 +++++++++-
>> include/trace/events/dma_buf.h | 160 +++++++++++++++++++++++++++++++++
>> 2 files changed, 207 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..6e04e12f149e 100644
>> --- a/drivers/dma-buf/dma-buf.c
>> +++ b/drivers/dma-buf/dma-buf.c
>> @@ -35,6 +35,9 @@
>>
>> #include "dma-buf-sysfs-stats.h"
>>
>> +#define CREATE_TRACE_POINTS
>> +#include <trace/events/dma_buf.h>
>> +
>> static inline int is_dma_buf_file(struct file *);
>>
>> static DEFINE_MUTEX(dmabuf_list_mutex);
>> @@ -220,6 +223,11 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
>> dmabuf->size >> PAGE_SHIFT)
>> return -EINVAL;
>>
>> + if (trace_dma_buf_mmap_internal_enabled()) {
>> + guard(spinlock)(&dmabuf->name_lock);
>> + trace_dma_buf_mmap_internal(dmabuf);
>> + }
>> +
>> return dmabuf->ops->mmap(dmabuf, vma);
>> }
>>
>> @@ -745,6 +753,11 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
>>
>> __dma_buf_list_add(dmabuf);
>>
>> + if (trace_dma_buf_export_enabled()) {
>> + guard(spinlock)(&dmabuf->name_lock);
>> + trace_dma_buf_export(dmabuf);
>> + }
>> +
>
> perhaps a macro similar to the one below
>
> #define DMA_BUF_TRACE(FUNC, ...) \
> do { \
> if (FUNC##_enabled()) { \
> guard(spinlock)(&dmabuf->name_lock); \
> FUNC(__VA_ARGS__); \
> } \
> } while (0)
>
>
> This would help us avoid duplicating a lot of code.
>
> could be:
> DMA_BUF_TRACE(trace_dma_buf_put, dmabuf);
> DMA_BUF_TRACE(trace_dma_buf_attach, dmabuf, dev);
>
> ?
Thinking more about it I was wondering if we really need the userspace assigned name in the tracepoint in the first place.
The ino should be sufficient to uniquely identify each dma-buf, tracing the name should only be printed if it's changing or otherwise we spam the tracelog quite a bit with it.
BTW We don't have any identification for an attachment, so when multiple devices attach to the same DMA-buf the trace would be quite meaningless. We should probably fix that.
Regards,
Christian.
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