162306a36Sopenharmony_ci.. SPDX-License-Identifier: GPL-2.0 262306a36Sopenharmony_ci 362306a36Sopenharmony_ci========== 462306a36Sopenharmony_ciSMC Sysctl 562306a36Sopenharmony_ci========== 662306a36Sopenharmony_ci 762306a36Sopenharmony_ci/proc/sys/net/smc/* Variables 862306a36Sopenharmony_ci============================= 962306a36Sopenharmony_ci 1062306a36Sopenharmony_ciautocorking_size - INTEGER 1162306a36Sopenharmony_ci Setting SMC auto corking size: 1262306a36Sopenharmony_ci SMC auto corking is like TCP auto corking from the application's 1362306a36Sopenharmony_ci perspective of view. When applications do consecutive small 1462306a36Sopenharmony_ci write()/sendmsg() system calls, we try to coalesce these small writes 1562306a36Sopenharmony_ci as much as possible, to lower total amount of CDC and RDMA Write been 1662306a36Sopenharmony_ci sent. 1762306a36Sopenharmony_ci autocorking_size limits the maximum corked bytes that can be sent to 1862306a36Sopenharmony_ci the under device in 1 single sending. If set to 0, the SMC auto corking 1962306a36Sopenharmony_ci is disabled. 2062306a36Sopenharmony_ci Applications can still use TCP_CORK for optimal behavior when they 2162306a36Sopenharmony_ci know how/when to uncork their sockets. 2262306a36Sopenharmony_ci 2362306a36Sopenharmony_ci Default: 64K 2462306a36Sopenharmony_ci 2562306a36Sopenharmony_cismcr_buf_type - INTEGER 2662306a36Sopenharmony_ci Controls which type of sndbufs and RMBs to use in later newly created 2762306a36Sopenharmony_ci SMC-R link group. Only for SMC-R. 2862306a36Sopenharmony_ci 2962306a36Sopenharmony_ci Default: 0 (physically contiguous sndbufs and RMBs) 3062306a36Sopenharmony_ci 3162306a36Sopenharmony_ci Possible values: 3262306a36Sopenharmony_ci 3362306a36Sopenharmony_ci - 0 - Use physically contiguous buffers 3462306a36Sopenharmony_ci - 1 - Use virtually contiguous buffers 3562306a36Sopenharmony_ci - 2 - Mixed use of the two types. Try physically contiguous buffers first. 3662306a36Sopenharmony_ci If not available, use virtually contiguous buffers then. 3762306a36Sopenharmony_ci 3862306a36Sopenharmony_cismcr_testlink_time - INTEGER 3962306a36Sopenharmony_ci How frequently SMC-R link sends out TEST_LINK LLC messages to confirm 4062306a36Sopenharmony_ci viability, after the last activity of connections on it. Value 0 means 4162306a36Sopenharmony_ci disabling TEST_LINK. 4262306a36Sopenharmony_ci 4362306a36Sopenharmony_ci Default: 30 seconds. 4462306a36Sopenharmony_ci 4562306a36Sopenharmony_ciwmem - INTEGER 4662306a36Sopenharmony_ci Initial size of send buffer used by SMC sockets. 4762306a36Sopenharmony_ci The default value inherits from net.ipv4.tcp_wmem[1]. 4862306a36Sopenharmony_ci 4962306a36Sopenharmony_ci The minimum value is 16KiB and there is no hard limit for max value, but 5062306a36Sopenharmony_ci only allowed 512KiB for SMC-R and 1MiB for SMC-D. 5162306a36Sopenharmony_ci 5262306a36Sopenharmony_ci Default: 16K 5362306a36Sopenharmony_ci 5462306a36Sopenharmony_cirmem - INTEGER 5562306a36Sopenharmony_ci Initial size of receive buffer (RMB) used by SMC sockets. 5662306a36Sopenharmony_ci The default value inherits from net.ipv4.tcp_rmem[1]. 5762306a36Sopenharmony_ci 5862306a36Sopenharmony_ci The minimum value is 16KiB and there is no hard limit for max value, but 5962306a36Sopenharmony_ci only allowed 512KiB for SMC-R and 1MiB for SMC-D. 6062306a36Sopenharmony_ci 6162306a36Sopenharmony_ci Default: 128K 62