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Date: Mon, 29 Dec 2025 11:15:47 +0800 Message-Id: <20251229031547.59272-1-gxxa03070307@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: gaoxiang17 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= =3Dqcom,system size=3D12685312 ino=3D2738 binder:3016_1-3102 [006] ...1. 255.126528: dma_buf_fd: exp_name=3Dq= com,system size=3D12685312 ino=3D2738 fd=3D8 binder:3016_1-3102 [006] ...1. 255.126642: dma_buf_mmap_internal: e= xp_name=3Dqcom,system size=3D28672 ino=3D2739 kworker/6:1-86 [006] ...1. 255.127194: dma_buf_put: exp_name=3D= qcom,system size=3D12685312 ino=3D2738 RenderThread-9293 [006] ...1. 316.618179: dma_buf_get: exp_name=3D= qcom,system size=3D12771328 ino=3D2762 fd=3D176 RenderThread-9293 [006] ...1. 316.618195: dma_buf_dynamic_attach: = exp_name=3Dqcom,system size=3D12771328 ino=3D2762 attachment:ffffff880a18dd= 00 is_dynamic=3D0 dev_name=3Dkgsl-3d0 RenderThread-9293 [006] ...1. 318.878220: dma_buf_detach: exp_name= =3Dqcom,system size=3D12771328 ino=3D2762 attachment:ffffff880a18dd00 is_dy= namic=3D0 dev_name=3Dkgsl-3d0 Signed-off-by: Xiang Gao Reviewed-by: Steven Rostedt (Google) --- Changes since v11: https://lore.kernel.org/all/20251225121119.2194228-1-gxx= a03070307@gmail.com/ - Lined up the backslashes nicely for the macro DMA_BUF_TRACE. - Used DEFINE_EVENT_CONDITION() to move the condition branch into the trace= point. Changes since v10: https://lore.kernel.org/all/20251224013455.1649879-1-gxx= a03070307@gmail.com/ - Always expose dmabuf->name_lock if lockdep is enabled. Changes since v9: https://lore.kernel.org/all/20251223032749.1371913-1-gxxa= 03070307@gmail.com/ - Fixed some whitespace issues with the macro DMA_BUF_TRACE again. Changes since v8: https://lore.kernel.org/all/20251218062853.819744-1-gxxa0= 3070307@gmail.com/ - Expose dmabuf->name_lock when lockdep is enabled but trace event is not. Changes since v7: https://lore.kernel.org/all/20251217105132.643300-1-gxxa0= 3070307@gmail.com/ - Fixed some whitespace issues with the macro DMA_BUF_TRACE. Changes since v6: https://lore.kernel.org/all/20251216063952.516364-1-gxxa0= 3070307@gmail.com/ - Add a comment for the macro DMA_BUF_TRACE. Changes since v5: https://lore.kernel.org/all/20251201112148.843572-1-gxxa0= 3070307@gmail.com/ - Add the macro DMA_BUF_TRACE. - Modify the commit message. Changes since v4: https://lore.kernel.org/all/20251128085215.550100-1-gxxa0= 3070307@gmail.com/ - Remove the tracepoints exporting. - Remove the file refcount for the trace. - Print the dev_name last. - Add the parameter of whether dma_buf attachment is dynamic. Changes since v3: https://lore.kernel.org/all/20251127004352.376307-1-gxxa0= 3070307@gmail.com/ - Take the dmabuf->name_lock around the tracepoint call itself. - Used DECLARE_EVENT_CLASS() and a DEFINE_EVENT(). Changes since v2: https://lore.kernel.org/all/20251125162949.220488-1-gxxa0= 3070307@gmail.com/ - Add more explanation to the commit message. drivers/dma-buf/dma-buf.c | 48 +++++++++- include/trace/events/dma_buf.h | 159 +++++++++++++++++++++++++++++++++ 2 files changed, 205 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..dee59d4c0b12 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -35,6 +35,26 @@ =20 #include "dma-buf-sysfs-stats.h" =20 +#define CREATE_TRACE_POINTS +#include + +/* + * 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 *); =20 static DEFINE_MUTEX(dmabuf_list_mutex); @@ -220,6 +240,8 @@ static int dma_buf_mmap_internal(struct file *file, str= uct vm_area_struct *vma) dmabuf->size >> PAGE_SHIFT) return -EINVAL; =20 + DMA_BUF_TRACE(trace_dma_buf_mmap_internal, dmabuf); + return dmabuf->ops->mmap(dmabuf, vma); } =20 @@ -745,6 +767,8 @@ struct dma_buf *dma_buf_export(const struct dma_buf_exp= ort_info *exp_info) =20 __dma_buf_list_add(dmabuf); =20 + DMA_BUF_TRACE(trace_dma_buf_export, dmabuf); + return dmabuf; =20 err_dmabuf: @@ -768,10 +792,15 @@ 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; =20 - return FD_ADD(flags, dmabuf->file); + fd =3D FD_ADD(flags, dmabuf->file); + DMA_BUF_TRACE(trace_dma_buf_fd, dmabuf, fd); + + return fd; } EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF"); =20 @@ -786,6 +815,7 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF"); struct dma_buf *dma_buf_get(int fd) { struct file *file; + struct dma_buf *dmabuf; =20 file =3D fget(fd); =20 @@ -797,7 +827,11 @@ struct dma_buf *dma_buf_get(int fd) return ERR_PTR(-EINVAL); } =20 - return file->private_data; + dmabuf =3D file->private_data; + + DMA_BUF_TRACE(trace_dma_buf_get, dmabuf, fd); + + return dmabuf; } EXPORT_SYMBOL_NS_GPL(dma_buf_get, "DMA_BUF"); =20 @@ -817,6 +851,8 @@ void dma_buf_put(struct dma_buf *dmabuf) return; =20 fput(dmabuf->file); + + DMA_BUF_TRACE(trace_dma_buf_put, dmabuf); } EXPORT_SYMBOL_NS_GPL(dma_buf_put, "DMA_BUF"); =20 @@ -971,6 +1007,9 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct = device *dev, list_add(&attach->node, &dmabuf->attachments); dma_resv_unlock(dmabuf->resv); =20 + DMA_BUF_TRACE(trace_dma_buf_dynamic_attach, dmabuf, attach, + dma_buf_attachment_is_dynamic(attach), dev); + return attach; =20 err_attach: @@ -1015,6 +1054,9 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dm= a_buf_attachment *attach) if (dmabuf->ops->detach) dmabuf->ops->detach(dmabuf, attach); =20 + 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"); @@ -1480,6 +1522,8 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_ar= ea_struct *vma, vma_set_file(vma, dmabuf->file); vma->vm_pgoff =3D pgoff; =20 + 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..3bb88d05bcc8 --- /dev/null +++ b/include/trace/events/dma_buf.h @@ -0,0 +1,159 @@ +/* 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 +#include + +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 =3D dmabuf->size; + __entry->ino =3D dmabuf->file->f_inode->i_ino; + ), + + TP_printk("exp_name=3D%s size=3D%zu ino=3D%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 =3D dmabuf->size; + __entry->ino =3D dmabuf->file->f_inode->i_ino; + __entry->is_dynamic =3D is_dynamic; + __entry->attach =3D attach; + ), + + TP_printk("exp_name=3D%s size=3D%zu ino=3D%lu attachment:%p is_dynamic=3D= %d dev_name=3D%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 =3D dmabuf->size; + __entry->ino =3D dmabuf->file->f_inode->i_ino; + __entry->fd =3D fd; + ), + + TP_printk("exp_name=3D%s size=3D%zu ino=3D%lu fd=3D%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_CONDITION(dma_buf_fd, dma_buf_fd, + + TP_PROTO(struct dma_buf *dmabuf, int fd), + + TP_ARGS(dmabuf, fd), + + TP_CONDITION(fd >=3D 0) +); + +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 --=20 2.34.1