.. 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.

smcr_testlink_time - INTEGER
	How frequently SMC-R link sends out TEST_LINK LLC messages to confirm
	viability, after the last activity of connections on it. Value 0 means
	disabling TEST_LINK.

	Default: 30 seconds.

smcr_max_links_per_lgr - INTEGER
	Controls the max number of links can be added to a SMC-R link group. Notice that
	the actual number of the links added to a SMC-R link group depends on the number
	of RDMA devices exist in the system. The acceptable value ranges from 1 to 2. Only
	for SMC-R v2.1 and later.

	Default: 2

smcr_max_conns_per_lgr - INTEGER
	Controls the max number of connections can be added to a SMC-R link group. The
	acceptable value ranges from 16 to 255. Only for SMC-R v2.1 and later.

	Default: 255
