What:		/sys/kernel/dmabuf/buffers
Date:		January 2021
KernelVersion:	v5.12
Contact:	Hridya Valsaraju <hridya@google.com>
Description:	The /sys/kernel/dmabuf/buffers directory contains a
		snapshot of the internal state of every DMA-BUF.
		/sys/kernel/dmabuf/buffers/<inode_number> will contain the
		statistics for the DMA-BUF with the unique inode number
		<inode_number>
Users:		kernel memory tuning/debugging tools

What:		/sys/kernel/dmabuf/buffers/<inode_number>/exporter_name
Date:		January 2021
KernelVersion:	v5.12
Contact:	Hridya Valsaraju <hridya@google.com>
Description:	This file is read-only and contains the name of the exporter of
		the DMA-BUF.

What:		/sys/kernel/dmabuf/buffers/<inode_number>/size
Date:		January 2021
KernelVersion:	v5.12
Contact:	Hridya Valsaraju <hridya@google.com>
Description:	This file is read-only and specifies the size of the DMA-BUF in
		bytes.

What:		/sys/kernel/dmabuf/buffers/<inode_number>/attachments
Date:		January 2021
KernelVersion:	v5.12
Contact:	Hridya Valsaraju <hridya@google.com>
Description:	This directory will contain subdirectories representing every
		attachment of the DMA-BUF.

What:		/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>
Date:		January 2021
KernelVersion:	v5.12
Contact:	Hridya Valsaraju <hridya@google.com>
Description:	This directory will contain information on the attaching device
		and the number of current distinct device mappings.

What:		/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/device
Date:		January 2021
KernelVersion:	v5.12
Contact:	Hridya Valsaraju <hridya@google.com>
Description:	This file is read-only and is a symlink to the attaching devices's
		sysfs entry.

What:		/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/map_counter
Date:		January 2021
KernelVersion:	v5.12
Contact:	Hridya Valsaraju <hridya@google.com>
Description:	This file is read-only and contains a map_counter indicating the
		number of distinct device mappings of the attachment.

What:		/sys/kernel/dmabuf/buffers/<inode_number>/mmap_count
Date:		January 2021
KernelVersion:	v5.10
Contact:	Kalesh Singh <kaleshsingh@google.com>
Description:	This file is read-only and contains a counter indicating the
		number of times the buffer has been mmap().
