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+.. 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.
+
+wmem - INTEGER
+ Initial size of send buffer used by SMC sockets.
+ The default value inherits from net.ipv4.tcp_wmem[1].
+
+ The minimum value is 16KiB and there is no hard limit for max value, but
+ only allowed 512KiB for SMC-R and 1MiB for SMC-D.
+
+ Default: 16K
+
+rmem - INTEGER
+ Initial size of receive buffer (RMB) used by SMC sockets.
+ The default value inherits from net.ipv4.tcp_rmem[1].
+
+ The minimum value is 16KiB and there is no hard limit for max value, but
+ only allowed 512KiB for SMC-R and 1MiB for SMC-D.
+
+ Default: 128K