1.. SPDX-License-Identifier: GPL-2.0 2 3========== 4SMC Sysctl 5========== 6 7/proc/sys/net/smc/* Variables 8============================= 9 10autocorking_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 24 25smcr_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. 37 38smcr_testlink_time - INTEGER 39 How frequently SMC-R link sends out TEST_LINK LLC messages to confirm 40 viability, after the last activity of connections on it. Value 0 means 41 disabling TEST_LINK. 42 43 Default: 30 seconds. 44 45wmem - INTEGER 46 Initial size of send buffer used by SMC sockets. 47 48 The minimum value is 16KiB and there is no hard limit for max value, but 49 only allowed 512KiB for SMC-R and 1MiB for SMC-D. 50 51 Default: 64KiB 52 53rmem - INTEGER 54 Initial size of receive buffer (RMB) used by SMC sockets. 55 56 The minimum value is 16KiB and there is no hard limit for max value, but 57 only allowed 512KiB for SMC-R and 1MiB for SMC-D. 58 59 Default: 64KiB 60 61smcr_max_links_per_lgr - INTEGER 62 Controls the max number of links can be added to a SMC-R link group. Notice that 63 the actual number of the links added to a SMC-R link group depends on the number 64 of RDMA devices exist in the system. The acceptable value ranges from 1 to 2. Only 65 for SMC-R v2.1 and later. 66 67 Default: 2 68 69smcr_max_conns_per_lgr - INTEGER 70 Controls the max number of connections can be added to a SMC-R link group. The 71 acceptable value ranges from 16 to 255. Only for SMC-R v2.1 and later. 72 73 Default: 255 74