[linux-2.6-block.git] / Documentation / networking / smc-sysctl.rst

.. SPDX-License-Identifier: GPL-2.0

==========
SMC Sysctl
==========

/proc/sys/net/smc/* Variables
=============================

autocorking_size - INTEGER
	Setting SMC auto corking size:
	SMC auto corking is like TCP auto corking from the application's
	perspective of view. When applications do consecutive small
	write()/sendmsg() system calls, we try to coalesce these small writes
	as much as possible, to lower total amount of CDC and RDMA Write been
	sent.
	autocorking_size limits the maximum corked bytes that can be sent to
	the under device in 1 single sending. If set to 0, the SMC auto corking
	is disabled.
	Applications can still use TCP_CORK for optimal behavior when they
	know how/when to uncork their sockets.

	Default: 64K

smcr_buf_type - INTEGER
        Controls which type of sndbufs and RMBs to use in later newly created
        SMC-R link group. Only for SMC-R.

        Default: 0 (physically contiguous sndbufs and RMBs)

        Possible values:

        - 0 - Use physically contiguous buffers
        - 1 - Use virtually contiguous buffers
        - 2 - Mixed use of the two types. Try physically contiguous buffers first.
          If not available, use virtually contiguous buffers then.
Commit	Line	Data
12bbb0d1 DL	1	.. SPDX-License-Identifier: GPL-2.0
12bbb0d1 DL	2
f9f52c34	3	==========
12bbb0d1	4	SMC Sysctl
f9f52c34	5	==========
12bbb0d1 DL	6
12bbb0d1 DL	7	/proc/sys/net/smc/* Variables
f9f52c34	8	=============================
12bbb0d1 DL	9
	10	autocorking_size - INTEGER
	11	Setting SMC auto corking size:
	12	SMC auto corking is like TCP auto corking from the application's
	13	perspective of view. When applications do consecutive small
	14	write()/sendmsg() system calls, we try to coalesce these small writes
	15	as much as possible, to lower total amount of CDC and RDMA Write been
	16	sent.
	17	autocorking_size limits the maximum corked bytes that can be sent to
	18	the under device in 1 single sending. If set to 0, the SMC auto corking
	19	is disabled.
	20	Applications can still use TCP_CORK for optimal behavior when they
	21	know how/when to uncork their sockets.
	22
	23	Default: 64K
4bc5008e WG	24
	25	smcr_buf_type - INTEGER
	26	Controls which type of sndbufs and RMBs to use in later newly created
	27	SMC-R link group. Only for SMC-R.
	28
	29	Default: 0 (physically contiguous sndbufs and RMBs)
	30
	31	Possible values:
	32
	33	- 0 - Use physically contiguous buffers
	34	- 1 - Use virtually contiguous buffers
	35	- 2 - Mixed use of the two types. Try physically contiguous buffers first.
	36	If not available, use virtually contiguous buffers then.