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: <...>-8342 [006] ..... 199.626433: dma_buf_export: exp_name=system name=(null) size=32768 ino=2337 f_refcnt=2 <...>-8342 [006] ..... 199.626436: dma_buf_fd: exp_name=system name=(null) size=32768 ino=2337 fd=853 f_refcnt=2 <...>-8342 [006] ..... 199.626472: dma_buf_mmap_internal: exp_name=system name=system size=32768 ino=2337 f_refcnt=6 <...>-3199 [006] ..... 200.719182: dma_buf_get: exp_name=qcom,system name=acb size=184320 ino=2331 fd=111 f_refcnt=6 <...>-894 [006] ..... 199.632342: dma_buf_put: exp_name=system name=system size=32768 ino=2337 f_refcnt=2 <...>-3199 [003] ..... 213.402200: dma_buf_attach: dev_name=soc:qcom,xxx exp_name=qcom,system name=acb size=184320 ino=2331 f_refcnt=7 <...>-1229 [004] ..... 213.850270: dma_buf_detach: exp_name=qcom,system name=acb size=184320 ino=2331 f_refcnt=6
Signed-off-by: Xiang Gao gaoxiang17@xiaomi.com --- drivers/dma-buf/dma-buf.c | 19 +++ include/trace/events/dma_buf.h | 281 +++++++++++++++++++++++++++++++++ 2 files changed, 300 insertions(+) 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..8b5af73f0218 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 +223,8 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) dmabuf->size >> PAGE_SHIFT) return -EINVAL;
+ trace_dma_buf_mmap_internal(dmabuf); + return dmabuf->ops->mmap(dmabuf, vma); }
@@ -745,6 +750,8 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
__dma_buf_list_add(dmabuf);
+ trace_dma_buf_export(dmabuf); + return dmabuf;
err_dmabuf: @@ -779,6 +786,8 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags)
fd_install(fd, dmabuf->file);
+ trace_dma_buf_fd(dmabuf, fd); + return fd; } EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF"); @@ -805,6 +814,8 @@ struct dma_buf *dma_buf_get(int fd) return ERR_PTR(-EINVAL); }
+ trace_dma_buf_get(fd, file); + return file->private_data; } EXPORT_SYMBOL_NS_GPL(dma_buf_get, "DMA_BUF"); @@ -825,6 +836,8 @@ void dma_buf_put(struct dma_buf *dmabuf) return;
fput(dmabuf->file); + + trace_dma_buf_put(dmabuf); } EXPORT_SYMBOL_NS_GPL(dma_buf_put, "DMA_BUF");
@@ -998,6 +1011,8 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_dynamic_attach, "DMA_BUF"); struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, struct device *dev) { + trace_dma_buf_attach(dmabuf, dev); + return dma_buf_dynamic_attach(dmabuf, dev, NULL, NULL); } EXPORT_SYMBOL_NS_GPL(dma_buf_attach, "DMA_BUF"); @@ -1024,6 +1039,8 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) dmabuf->ops->detach(dmabuf, attach);
kfree(attach); + + trace_dma_buf_detach(dmabuf); } EXPORT_SYMBOL_NS_GPL(dma_buf_detach, "DMA_BUF");
@@ -1488,6 +1505,8 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, vma_set_file(vma, dmabuf->file); vma->vm_pgoff = pgoff;
+ 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..ab593dea4617 --- /dev/null +++ b/include/trace/events/dma_buf.h @@ -0,0 +1,281 @@ +/* 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> + +TRACE_EVENT(dma_buf_export, + + 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) + __field(long, f_refcnt) + ), + + TP_fast_assign( + __assign_str(exp_name); + spin_lock(&dmabuf->name_lock); + __assign_str(name); + spin_unlock(&dmabuf->name_lock); + __entry->size = dmabuf->size; + __entry->ino = dmabuf->file->f_inode->i_ino; + __entry->f_refcnt = file_count(dmabuf->file); + ), + + TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld", + __get_str(exp_name), + __get_str(name), + __entry->size, + __entry->ino, + __entry->f_refcnt) +); + +TRACE_EVENT(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) + __field(long, f_refcnt) + ), + + TP_fast_assign( + __assign_str(exp_name); + spin_lock(&dmabuf->name_lock); + __assign_str(name); + spin_unlock(&dmabuf->name_lock); + __entry->size = dmabuf->size; + __entry->ino = dmabuf->file->f_inode->i_ino; + __entry->fd = fd; + __entry->f_refcnt = file_count(dmabuf->file); + ), + + TP_printk("exp_name=%s name=%s size=%zu ino=%lu fd=%d f_refcnt=%ld", + __get_str(exp_name), + __get_str(name), + __entry->size, + __entry->ino, + __entry->fd, + __entry->f_refcnt) +); + +TRACE_EVENT(dma_buf_mmap_internal, + + 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) + __field(long, f_refcnt) + ), + + TP_fast_assign( + __assign_str(exp_name); + spin_lock(&dmabuf->name_lock); + __assign_str(name); + spin_unlock(&dmabuf->name_lock); + __entry->size = dmabuf->size; + __entry->ino = dmabuf->file->f_inode->i_ino; + __entry->f_refcnt = file_count(dmabuf->file); + ), + + TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld", + __get_str(exp_name), + __get_str(name), + __entry->size, + __entry->ino, + __entry->f_refcnt) +); + +TRACE_EVENT(dma_buf_mmap, + + 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) + __field(long, f_refcnt) + ), + + TP_fast_assign( + __assign_str(exp_name); + spin_lock(&dmabuf->name_lock); + __assign_str(name); + spin_unlock(&dmabuf->name_lock); + __entry->size = dmabuf->size; + __entry->ino = dmabuf->file->f_inode->i_ino; + __entry->f_refcnt = file_count(dmabuf->file); + ), + + TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld", + __get_str(exp_name), + __get_str(name), + __entry->size, + __entry->ino, + __entry->f_refcnt) +); + +TRACE_EVENT(dma_buf_attach, + + TP_PROTO(struct dma_buf *dmabuf, struct device *dev), + + TP_ARGS(dmabuf, dev), + + TP_STRUCT__entry( + __string(dname, dev_name(dev)) + __string(exp_name, dmabuf->exp_name) + __string(name, dmabuf->name) + __field(size_t, size) + __field(ino_t, ino) + __field(long, f_refcnt) + ), + + TP_fast_assign( + __assign_str(dname); + __assign_str(exp_name); + spin_lock(&dmabuf->name_lock); + __assign_str(name); + spin_unlock(&dmabuf->name_lock); + __entry->size = dmabuf->size; + __entry->ino = dmabuf->file->f_inode->i_ino; + __entry->f_refcnt = file_count(dmabuf->file); + ), + + TP_printk("dev_name=%s exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld", + __get_str(dname), + __get_str(exp_name), + __get_str(name), + __entry->size, + __entry->ino, + __entry->f_refcnt) +); + +TRACE_EVENT(dma_buf_detach, + + 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) + __field(long, f_refcnt) + ), + + TP_fast_assign( + __assign_str(exp_name); + spin_lock(&dmabuf->name_lock); + __assign_str(name); + spin_unlock(&dmabuf->name_lock); + __entry->size = dmabuf->size; + __entry->ino = dmabuf->file->f_inode->i_ino; + __entry->f_refcnt = file_count(dmabuf->file); + ), + + TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld", + __get_str(exp_name), + __get_str(name), + __entry->size, + __entry->ino, + __entry->f_refcnt) +); + +TRACE_EVENT(dma_buf_get, + + TP_PROTO(int fd, struct file *file), + + TP_ARGS(fd, file), + + TP_STRUCT__entry( + __string(exp_name, ((struct dma_buf *)file->private_data)->exp_name) + __string(name, ((struct dma_buf *)file->private_data)->name) + __field(size_t, size) + __field(ino_t, ino) + __field(int, fd) + __field(long, f_refcnt) + ), + + TP_fast_assign( + struct dma_buf *dmabuf = (struct dma_buf *)file->private_data; + + __assign_str(exp_name); + spin_lock(&dmabuf->name_lock); + __assign_str(name); + spin_unlock(&dmabuf->name_lock); + __entry->size = dmabuf->size; + __entry->ino = dmabuf->file->f_inode->i_ino; + __entry->fd = fd; + __entry->f_refcnt = file_count(file); + ), + + TP_printk("exp_name=%s name=%s size=%zu ino=%lu fd=%d f_refcnt=%ld", + __get_str(exp_name), + __get_str(name), + __entry->size, + __entry->ino, + __entry->fd, + __entry->f_refcnt) +); + +TRACE_EVENT(dma_buf_put, + + 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) + __field(long, f_refcnt) + ), + + TP_fast_assign( + __assign_str(exp_name); + spin_lock(&dmabuf->name_lock); + __assign_str(name); + spin_unlock(&dmabuf->name_lock); + __entry->size = dmabuf->size; + __entry->ino = dmabuf->file->f_inode->i_ino; + __entry->f_refcnt = file_count(dmabuf->file); + ), + + TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld", + __get_str(exp_name), + __get_str(name), + __entry->size, + __entry->ino, + __entry->f_refcnt) +); + +#endif /* _TRACE_DMA_BUF_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h>
On Wed, 26 Nov 2025 00:29:49 +0800 Xiang Gao gxxa03070307@gmail.com wrote:
+++ b/include/trace/events/dma_buf.h @@ -0,0 +1,281 @@ +/* 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>
+TRACE_EVENT(dma_buf_export,
- 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)__field(long, f_refcnt)- ),
- TP_fast_assign(
__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);
The above isn't doing what you think it's doing. The name is assigned before this by the above __string(name, dmabuf->name).
You really shouldn't be taking any locks in a tracepoint. A tracepoint is a callback, that isn't called most of the time. You could be hiding very hard to find deadlocks by taking a lock in a tracepoint callback.
You need to take the lock around the tracepoint call itself where it is called in the code. Not in the TRACE_EVENT.
You may need to have something like:
@@ -220,6 +223,8 @@ 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->namelock); + trace_dma_buf_mmap_internal(dmabuf); + } + return dmabuf->ops->mmap(dmabuf, vma); }
The "trace_dma_buf_mmap_internal_enabled()" is a static branch, where it is either a nop or a jump to the tracing code. It's not a normal conditional branch. It acts the same as tracepoints themselves do.
__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);- ),
- TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",
__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
Below seems to be a lot of very similar TRACE_EVENT()s. A TRACE_EVENT() is literally defined as:
#define TRACE_EVENT(name, proto, args, tstruct, assign, print) \ DECLARE_EVENT_CLASS(name, \ PARAMS(proto), \ PARAMS(args), \ PARAMS(tstruct), \ PARAMS(assign), \ PARAMS(print)); \ DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
That is, it is both a DECLARE_EVENT_CLASS() and a DEFINE_EVENT(). You can make one DECLARE_EVENT_CLASS() and use many DEFINE_EVENT()s with it.
Each DECLARE_EVENT_CLASS() takes up around 4 to 5 kilobytes of memory. Each DEFINE_EVENT() takes around 300 bytes to 1K of memory. The more DEFINE_EVENT()s you use with a single DECLARE_EVENT_CLASS(), the more memory you save. Please try to do that.
-- Steve
+TRACE_EVENT(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)__field(long, f_refcnt)- ),
- TP_fast_assign(
__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->fd = fd;__entry->f_refcnt = file_count(dmabuf->file);- ),
- TP_printk("exp_name=%s name=%s size=%zu ino=%lu fd=%d f_refcnt=%ld",
__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->fd,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_mmap_internal,
- 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)__field(long, f_refcnt)- ),
- TP_fast_assign(
__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);- ),
- TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",
__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_mmap,
- 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)__field(long, f_refcnt)- ),
- TP_fast_assign(
__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);- ),
- TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",
__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_attach,
- TP_PROTO(struct dma_buf *dmabuf, struct device *dev),
- TP_ARGS(dmabuf, dev),
- TP_STRUCT__entry(
__string(dname, dev_name(dev))__string(exp_name, dmabuf->exp_name)__string(name, dmabuf->name)__field(size_t, size)__field(ino_t, ino)__field(long, f_refcnt)- ),
- TP_fast_assign(
__assign_str(dname);__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);- ),
- TP_printk("dev_name=%s exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",
__get_str(dname),__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_detach,
- 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)__field(long, f_refcnt)- ),
- TP_fast_assign(
__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);- ),
- TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",
__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_get,
- TP_PROTO(int fd, struct file *file),
- TP_ARGS(fd, file),
- TP_STRUCT__entry(
__string(exp_name, ((struct dma_buf *)file->private_data)->exp_name)__string(name, ((struct dma_buf *)file->private_data)->name)__field(size_t, size)__field(ino_t, ino)__field(int, fd)__field(long, f_refcnt)- ),
- TP_fast_assign(
struct dma_buf *dmabuf = (struct dma_buf *)file->private_data;__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->fd = fd;__entry->f_refcnt = file_count(file);- ),
- TP_printk("exp_name=%s name=%s size=%zu ino=%lu fd=%d f_refcnt=%ld",
__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->fd,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_put,
- 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)__field(long, f_refcnt)- ),
- TP_fast_assign(
__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);- ),
- TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",
__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
+#endif /* _TRACE_DMA_BUF_H */
+/* This part must be outside protection */ +#include <trace/define_trace.h>
ok, thanks.
________________________________ 发件人: Steven Rostedt rostedt@goodmis.org 发送时间: 2025年11月26日 9:39:24 收件人: Xiang Gao 抄送: sumit.semwal@linaro.org; christian.koenig@amd.com; mhiramat@kernel.org; linux-media@vger.kernel.org; dri-devel@lists.freedesktop.org; linaro-mm-sig@lists.linaro.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 v2] 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 Wed, 26 Nov 2025 00:29:49 +0800 Xiang Gao gxxa03070307@gmail.com wrote:
+++ b/include/trace/events/dma_buf.h @@ -0,0 +1,281 @@ +/* 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>
+TRACE_EVENT(dma_buf_export,
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)__field(long, f_refcnt)),TP_fast_assign(__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);
The above isn't doing what you think it's doing. The name is assigned before this by the above __string(name, dmabuf->name).
You really shouldn't be taking any locks in a tracepoint. A tracepoint is a callback, that isn't called most of the time. You could be hiding very hard to find deadlocks by taking a lock in a tracepoint callback.
You need to take the lock around the tracepoint call itself where it is called in the code. Not in the TRACE_EVENT.
You may need to have something like:
@@ -220,6 +223,8 @@ 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->namelock); + trace_dma_buf_mmap_internal(dmabuf); + } + return dmabuf->ops->mmap(dmabuf, vma); }
The "trace_dma_buf_mmap_internal_enabled()" is a static branch, where it is either a nop or a jump to the tracing code. It's not a normal conditional branch. It acts the same as tracepoints themselves do.
__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);),TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
Below seems to be a lot of very similar TRACE_EVENT()s. A TRACE_EVENT() is literally defined as:
#define TRACE_EVENT(name, proto, args, tstruct, assign, print) \ DECLARE_EVENT_CLASS(name, \ PARAMS(proto), \ PARAMS(args), \ PARAMS(tstruct), \ PARAMS(assign), \ PARAMS(print)); \ DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
That is, it is both a DECLARE_EVENT_CLASS() and a DEFINE_EVENT(). You can make one DECLARE_EVENT_CLASS() and use many DEFINE_EVENT()s with it.
Each DECLARE_EVENT_CLASS() takes up around 4 to 5 kilobytes of memory. Each DEFINE_EVENT() takes around 300 bytes to 1K of memory. The more DEFINE_EVENT()s you use with a single DECLARE_EVENT_CLASS(), the more memory you save. Please try to do that.
-- Steve
+TRACE_EVENT(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)__field(long, f_refcnt)),TP_fast_assign(__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->fd = fd;__entry->f_refcnt = file_count(dmabuf->file);),TP_printk("exp_name=%s name=%s size=%zu ino=%lu fd=%d f_refcnt=%ld",__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->fd,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_mmap_internal,
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)__field(long, f_refcnt)),TP_fast_assign(__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);),TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_mmap,
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)__field(long, f_refcnt)),TP_fast_assign(__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);),TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_attach,
TP_PROTO(struct dma_buf *dmabuf, struct device *dev),TP_ARGS(dmabuf, dev),TP_STRUCT__entry(__string(dname, dev_name(dev))__string(exp_name, dmabuf->exp_name)__string(name, dmabuf->name)__field(size_t, size)__field(ino_t, ino)__field(long, f_refcnt)),TP_fast_assign(__assign_str(dname);__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);),TP_printk("dev_name=%s exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",__get_str(dname),__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_detach,
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)__field(long, f_refcnt)),TP_fast_assign(__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);),TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_get,
TP_PROTO(int fd, struct file *file),TP_ARGS(fd, file),TP_STRUCT__entry(__string(exp_name, ((struct dma_buf *)file->private_data)->exp_name)__string(name, ((struct dma_buf *)file->private_data)->name)__field(size_t, size)__field(ino_t, ino)__field(int, fd)__field(long, f_refcnt)),TP_fast_assign(struct dma_buf *dmabuf = (struct dma_buf *)file->private_data;__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->fd = fd;__entry->f_refcnt = file_count(file);),TP_printk("exp_name=%s name=%s size=%zu ino=%lu fd=%d f_refcnt=%ld",__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->fd,__entry->f_refcnt)+);
+TRACE_EVENT(dma_buf_put,
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)__field(long, f_refcnt)),TP_fast_assign(__assign_str(exp_name);spin_lock(&dmabuf->name_lock);__assign_str(name);spin_unlock(&dmabuf->name_lock);__entry->size = dmabuf->size;__entry->ino = dmabuf->file->f_inode->i_ino;__entry->f_refcnt = file_count(dmabuf->file);),TP_printk("exp_name=%s name=%s size=%zu ino=%lu f_refcnt=%ld",__get_str(exp_name),__get_str(name),__entry->size,__entry->ino,__entry->f_refcnt)+);
+#endif /* _TRACE_DMA_BUF_H */
+/* This part must be outside protection */ +#include <trace/define_trace.h>
linaro-mm-sig@lists.linaro.org
-
Steven Rostedt -
Xiang Gao -
高翔