112bbb0d1SDust Li.. SPDX-License-Identifier: GPL-2.0 212bbb0d1SDust Li 3f9f52c34SDust Li========== 412bbb0d1SDust LiSMC Sysctl 5f9f52c34SDust Li========== 612bbb0d1SDust Li 712bbb0d1SDust Li/proc/sys/net/smc/* Variables 8f9f52c34SDust Li============================= 912bbb0d1SDust Li 1012bbb0d1SDust Liautocorking_size - INTEGER 1112bbb0d1SDust Li Setting SMC auto corking size: 1212bbb0d1SDust Li SMC auto corking is like TCP auto corking from the application's 1312bbb0d1SDust Li perspective of view. When applications do consecutive small 1412bbb0d1SDust Li write()/sendmsg() system calls, we try to coalesce these small writes 1512bbb0d1SDust Li as much as possible, to lower total amount of CDC and RDMA Write been 1612bbb0d1SDust Li sent. 1712bbb0d1SDust Li autocorking_size limits the maximum corked bytes that can be sent to 1812bbb0d1SDust Li the under device in 1 single sending. If set to 0, the SMC auto corking 1912bbb0d1SDust Li is disabled. 2012bbb0d1SDust Li Applications can still use TCP_CORK for optimal behavior when they 2112bbb0d1SDust Li know how/when to uncork their sockets. 2212bbb0d1SDust Li 2312bbb0d1SDust Li Default: 64K 244bc5008eSWen Gu 254bc5008eSWen Gusmcr_buf_type - INTEGER 264bc5008eSWen Gu Controls which type of sndbufs and RMBs to use in later newly created 274bc5008eSWen Gu SMC-R link group. Only for SMC-R. 284bc5008eSWen Gu 294bc5008eSWen Gu Default: 0 (physically contiguous sndbufs and RMBs) 304bc5008eSWen Gu 314bc5008eSWen Gu Possible values: 324bc5008eSWen Gu 334bc5008eSWen Gu - 0 - Use physically contiguous buffers 344bc5008eSWen Gu - 1 - Use virtually contiguous buffers 354bc5008eSWen Gu - 2 - Mixed use of the two types. Try physically contiguous buffers first. 364bc5008eSWen Gu If not available, use virtually contiguous buffers then. 3777eee325SWen Gu 3877eee325SWen Gusmcr_testlink_time - INTEGER 3977eee325SWen Gu How frequently SMC-R link sends out TEST_LINK LLC messages to confirm 4077eee325SWen Gu viability, after the last activity of connections on it. Value 0 means 4177eee325SWen Gu disabling TEST_LINK. 4277eee325SWen Gu 4377eee325SWen Gu Default: 30 seconds. 44*0227f058STony Lu 45*0227f058STony Luwmem - INTEGER 46*0227f058STony Lu Initial size of send buffer used by SMC sockets. 47*0227f058STony Lu The default value inherits from net.ipv4.tcp_wmem[1]. 48*0227f058STony Lu 49*0227f058STony Lu The minimum value is 16KiB and there is no hard limit for max value, but 50*0227f058STony Lu only allowed 512KiB for SMC-R and 1MiB for SMC-D. 51*0227f058STony Lu 52*0227f058STony Lu Default: 16K 53*0227f058STony Lu 54*0227f058STony Lurmem - INTEGER 55*0227f058STony Lu Initial size of receive buffer (RMB) used by SMC sockets. 56*0227f058STony Lu The default value inherits from net.ipv4.tcp_rmem[1]. 57*0227f058STony Lu 58*0227f058STony Lu The minimum value is 16KiB and there is no hard limit for max value, but 59*0227f058STony Lu only allowed 512KiB for SMC-R and 1MiB for SMC-D. 60*0227f058STony Lu 61*0227f058STony Lu Default: 128K 62