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From:   Guangguan Wang <guangguan.wang@linux.alibaba.com>
To:     kgraul@linux.ibm.com, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, leon@kernel.org
Cc:     linux-s390@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH net-next v2 0/2] net/smc: send and write inline optimization for smc
Date:   Sat, 14 May 2022 18:27:37 +0800
Message-Id: <20220514102739.41252-1-guangguan.wang@linux.alibaba.com>
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Send cdc msgs and write data inline if qp has sufficent inline
space, helps latency reducing. 

In my test environment, which are 2 VMs running on the same
physical host and whose NICs(ConnectX-4Lx) are working on
SR-IOV mode, qperf shows 0.4us-1.3us improvement in latency.

Test command:
server: smc_run taskset -c 1 qperf
client: smc_run taskset -c 1 qperf <server ip> -oo \
		msg_size:1:2K:*2 -t 30 -vu tcp_lat

The results shown below:
msgsize     before       after
1B          11.9 us      10.6 us (-1.3 us)
2B          11.7 us      10.7 us (-1.0 us)
4B          11.7 us      10.7 us (-1.0 us)
8B          11.6 us      10.6 us (-1.0 us)
16B         11.7 us      10.7 us (-1.0 us)
32B         11.7 us      10.6 us (-1.1 us)
64B         11.7 us      11.2 us (-0.5 us)
128B        11.6 us      11.2 us (-0.4 us)
256B        11.8 us      11.2 us (-0.6 us)
512B        11.8 us      11.3 us (-0.5 us)
1KB         11.9 us      11.5 us (-0.4 us)
2KB         12.1 us      11.5 us (-0.6 us)

Guangguan Wang (2):
  net/smc: send cdc msg inline if qp has sufficient inline space
  net/smc: rdma write inline if qp has sufficient inline space

 net/smc/smc_ib.c |  1 +
 net/smc/smc_tx.c | 17 ++++++++++++-----
 net/smc/smc_wr.c |  5 ++++-
 3 files changed, 17 insertions(+), 6 deletions(-)

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