2023-09-22 04:55:52

by Wenjia Zhang

[permalink] [raw]
Subject: Re: [PATCH net-next v3 00/18] net/smc: implement virtual ISM extension and loopback-ism



On 21.09.23 15:19, Wen Gu wrote:
> Hi, all
>
> # Background
>
> SMC-D is now used in IBM z with ISM function to optimize network interconnect
> for intra-CPC communications. Inspired by this, we try to make SMC-D available
> on the non-s390 architecture through a software-simulated virtual ISM device,
> such as loopback-ism device here, to accelerate inter-process or inter-containers
> communication within the same OS.
>
> # Design
>
> This patch set includes 4 parts:
>
> - Patch #1-#3: decouple ISM device hard code from SMC-D stack.
> - Patch #4-#8: implement virtual ISM extension defined in SMCv2.1.
> - Patch #9-#13: implement loopback-ism device.
> - Patch #14-#18: memory copy optimization for the case using loopback.
>
> The loopback-ism device is designed as a kernel device and not be limited to
> a specific net namespace, ends of both inter-process connection (1/1' in diagram
> below) or inter-container connection (2/2' in diagram below) will find that peer
> shares the same loopback-ism device during the CLC handshake. Then loopback-ism
> device will be chosen.
>
> Container 1 (ns1) Container 2 (ns2)
> +-----------------------------------------+ +-------------------------+
> | +-------+ +-------+ +-------+ | | +-------+ |
> | | App A | | App B | | App C | | | | App D |<-+ |
> | +-------+ +---^---+ +-------+ | | +-------+ |(2') |
> | |127.0.0.1 (1')| |192.168.0.11 192.168.0.12| |
> | (1)| +--------+ | +--------+ |(2) | | +--------+ +--------+ |
> | `-->| lo |-` | eth0 |<-` | | | lo | | eth0 | |
> +---------+--|---^-+---+-----|--+---------+ +-+--------+---+-^------+-+
> | | | |
> Kernel | | | |
> +----+-------v---+-----------v----------------------------------+---+----+
> | | TCP | |
> | | | |
> | +--------------------------------------------------------------+ |
> | |
> | +--------------+ |
> | | smc loopback | |
> +---------------------------+--------------+-----------------------------+
>
>
> loopback-ism device allocs RMBs and sndbufs for each connection peer and 'moves'
> data from sndbuf at one end to RMB at the other end. Since communication occurs
> within the same kernel, the sndbuf can be mapped to peer RMB so that the data
> copy in loopback-ism case can be avoided.
>
> Container 1 (ns1) Container 2 (ns2)
> +-----------------------------------------+ +-------------------------+
> | +-------+ +-------+ +-------+ | | +-------+ |
> | | App A | | App B | | App C | | | | App D | |
> | +-------+ +--^----+ +-------+ | | +---^---+ |
> | | | | | | | |
> | (1) | (1') | (2) | | | (2') | |
> | | | | | | | |
> +-------|-----------|---------------|-----+ +------------|------------+
> | | | |
> Kernel | | | |
> +-------|-----------|---------------|-----------------------|------------+
> | +-----v-+ +-------+ +---v---+ +-------+ |
> | | snd A |-+ | RMB B |<--+ | snd C |-+ +->| RMB D | |
> | +-------+ | +-------+ | +-------+ | | +-------+ |
> | +-------+ | +-------+ | +-------+ | | +-------+ |
> | | RMB A | | | snd B | | | RMB C | | | | snd D | |
> | +-------+ | +-------+ | +-------+ | | +-------+ |
> | | +-------------v+ | |
> | +-------------->| smc loopback |---------+ |
> +---------------------------+--------------+-----------------------------+
>
> # Benchmark Test
>
> * Test environments:
> - VM with Intel Xeon Platinum 8 core 2.50GHz, 16 GiB mem.
> - SMC sndbuf/RMB size 1MB.
>
> * Test object:
> - TCP: run on TCP loopback.
> - domain: run on UNIX domain.
> - SMC lo: run on SMC loopback device.
>
> 1. ipc-benchmark (see [1])
>
> - ./<foo> -c 1000000 -s 100
>
> TCP domain SMC-lo
> Message
> rate (msg/s) 78855 107621(+36.41%) 153351(+94.47%)
>
> 2. sockperf
>
> - serv: <smc_run> taskset -c <cpu> sockperf sr --tcp
> - clnt: <smc_run> taskset -c <cpu> sockperf { tp | pp } --tcp --msg-size={ 64000 for tp | 14 for pp } -i 127.0.0.1 -t 30
>
> TCP SMC-lo
> Bandwidth(MBps) 5169.250 8007.080(+54.89%)
> Latency(us) 6.122 3.174(-48.15%)
>
> 3. nginx/wrk
>
> - serv: <smc_run> nginx
> - clnt: <smc_run> wrk -t 8 -c 1000 -d 30 http://127.0.0.1:80
>
> TCP SMC-lo
> Requests/s 197432.19 261056.09(+32.22%)
>
> 4. redis-benchmark
>
> - serv: <smc_run> redis-server
> - clnt: <smc_run> redis-benchmark -h 127.0.0.1 -q -t set,get -n 400000 -c 200 -d 1024
>
> TCP SMC-lo
> GET(Requests/s) 86244.07 122025.62(+41.48%)
> SET(Requests/s) 86749.08 120048.02(+38.38%)
>
> [1] https://github.com/goldsborough/ipc-bench
>
> v2->v3:
> - Fix build warning of patch#1 and patch#10.
>
> v1->v2:
> - Fix build error on s390 arch.
>
> Wen Gu (18):
> net/smc: decouple ism_dev from SMC-D device dump
> net/smc: decouple ism_dev from SMC-D DMB registration
> net/smc: extract v2 check helper from SMC-D device registration
> net/smc: support SMCv2.x supplemental features negotiation
> net/smc: reserve CHID range for SMC-D virtual device
> net/smc: extend GID to 128bits for virtual ISM device
> net/smc: disable SEID on non-s390 architecture
> net/smc: enable virtual ISM device feature bit
> net/smc: introduce SMC-D loopback device
> net/smc: implement ID-related operations of loopback
> net/smc: implement some unsupported operations of loopback
> net/smc: implement DMB-related operations of loopback
> net/smc: register loopback device as SMC-Dv2 device
> net/smc: add operation for getting DMB attribute
> net/smc: add operations for DMB attach and detach
> net/smc: avoid data copy from sndbuf to peer RMB in SMC-D
> net/smc: modify cursor update logic when sndbuf mapped to RMB
> net/smc: add interface implementation of loopback device
>
> drivers/s390/net/ism_drv.c | 19 +-
> include/net/smc.h | 32 ++-
> include/uapi/linux/smc.h | 3 +
> net/smc/Makefile | 2 +-
> net/smc/af_smc.c | 73 +++++--
> net/smc/smc.h | 7 +
> net/smc/smc_cdc.c | 56 ++++--
> net/smc/smc_cdc.h | 1 +
> net/smc/smc_clc.c | 56 ++++--
> net/smc/smc_clc.h | 10 +-
> net/smc/smc_core.c | 108 +++++++++-
> net/smc/smc_core.h | 9 +-
> net/smc/smc_diag.c | 6 +-
> net/smc/smc_ism.c | 100 +++++++---
> net/smc/smc_ism.h | 24 ++-
> net/smc/smc_loopback.c | 483 +++++++++++++++++++++++++++++++++++++++++++++
> net/smc/smc_loopback.h | 52 +++++
> net/smc/smc_pnet.c | 4 +-
> 18 files changed, 946 insertions(+), 99 deletions(-)
> create mode 100644 net/smc/smc_loopback.c
> create mode 100644 net/smc/smc_loopback.h
>

Hi Wen,

Thank you for the effort!
You can find my comments in the respective patches. One general question
from our team, could you please add a Kconfig option to turn off/on
loopback-ism?

BTW, I'm in vacation next week, my colleagues will follow on the answer
and update.

Thanks,
Wenjia


2023-09-22 12:24:43

by Wen Gu

[permalink] [raw]
Subject: Re: [PATCH net-next v3 00/18] net/smc: implement virtual ISM extension and loopback-ism



On 2023/9/22 07:31, Wenjia Zhang wrote:

>
> Hi Wen,
>
> Thank you for the effort!

Thank you very much for review, Wenjia.

> You can find my comments in the respective patches. One general question from our team, could you please add a Kconfig
> option to turn off/on loopback-ism?

Sure, I will add an option to turn off/on loopback-ism.

>
> BTW, I'm in vacation next week, my colleagues will follow on the answer and update.

Thank you. Enjoy the vacation!

Regards,
Wen Gu

>
> Thanks,
> Wenjia
>