| Message ID | 20230804170624.940883-1-gbayer@linux.ibm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | net/smc: Fix effective buffer size | expand |
Hello: This series was applied to netdev/net.git (main) by David S. Miller <davem@davemloft.net>: On Fri, 4 Aug 2023 19:06:22 +0200 you wrote: > Hi all, > > commit 0227f058aa29 ("net/smc: Unbind r/w buffer size from clcsock > and make them tunable") started to derive the effective buffer size for > SMC connections inconsistently in case a TCP fallback was used and > memory consumption of SMC with the default settings was doubled when > a connection negotiated SMC. That was not what we want. > > [...] Here is the summary with links: - [net,v3,1/2] net/smc: Fix setsockopt and sysctl to specify same buffer size again https://git.kernel.org/netdev/net/c/833bac7ec392 - [net,v3,2/2] net/smc: Use correct buffer sizes when switching between TCP and SMC https://git.kernel.org/netdev/net/c/30c3c4a4497c You are awesome, thank you!
Hi all, commit 0227f058aa29 ("net/smc: Unbind r/w buffer size from clcsock and make them tunable") started to derive the effective buffer size for SMC connections inconsistently in case a TCP fallback was used and memory consumption of SMC with the default settings was doubled when a connection negotiated SMC. That was not what we want. This series consolidates the resulting effective buffer size that is used with SMC sockets, which is based on Jan Karcher's effort (see [1]). For all TCP exchanges (in particular in case of a fall back when no SMC connection was possible) the values from net.ipv4.tcp_[rw]mem are used. If SMC succeeds in establishing a SMC connection, the newly introduced values from net.smc.[rw]mem are used. net.smc.[rw]mem is initialized to 64kB, respectively. Internal test have show this to be a good compromise between throughput/latency and memory consumption. Also net.smc.[rw]mem is now decoupled completely from any tuning through net.ipv4.tcp_[rw]mem. If a user chose to tune a socket's receive or send buffer size with setsockopt, this tuning is now consistently applied to either fall-back TCP or proper SMC connections over the socket. Thanks, Gerd v2 - v3: - Rebase to and resolve conflict of second patch with latest net/master. v1 - v2: - In second patch, use sock_net() helper as suggested by Tony and demanded by kernel test robot. Gerd Bayer (2): net/smc: Fix setsockopt and sysctl to specify same buffer size again net/smc: Use correct buffer sizes when switching between TCP and SMC net/smc/af_smc.c | 77 ++++++++++++++++++++++++++++++-------------- net/smc/smc.h | 2 +- net/smc/smc_clc.c | 4 +-- net/smc/smc_core.c | 25 +++++++------- net/smc/smc_sysctl.c | 10 ++++-- 5 files changed, 76 insertions(+), 42 deletions(-) base-commit: 1733d0be68ab1b89358a3b0471ef425fd61de7c5