On Mon, Nov 18, 2019 at 02:38:19PM +0800, wangqi wrote: > On 2019/11/16 上午12:07, Leon Romanovsky wrote: > > > On Fri, Nov 15, 2019 at 09:26:41PM +0800, QWang wrote: > >> Dear experts on RDMA, > >> We are sorry to disturb you. Because of a project, we need to > >> integrate soft-RoCE in our system. However ,we are very confused by our > >> soft-RoCE throughput results, which are quite low compared with TCP > >> throughput. The throughput of soft-RoCE in our tests measured by ib_send_bw > >> and ib_read_bw is only 2 Gbps (the net link bandwidth is 100 Gbps and the > >> two Xeon E5 servers with Mellanox ConnectX-4 cards are connected via > >> back-to-back, the OS is ubuntu16.04 with kernel 4.15.0-041500-generic). The > >> throughput of hard-RoCE and TCP are normal, which are 100 Gbps and 20 Gbps, > >> respectively. But in the figure 6 in the attached paper "A Performance > >> Comparison of Container Networking Alternatives", the throughput of > >> soft-RoCE can be up to 23 Gbps. In our tests, we get the open-source > >> soft-RoCE from github in https://github.com/linux-rdma. Do you know how can > >> we get such high bandwidth? Do we need to configure some OS system settings? > >> We find that in 2017, someone finds the same problem and he posts all > >> his detailed results on https://bugzilla.kernel.org/show_bug.cgi?id=190951 ; > >> . But it remains unsolved. His results are nearly the same with our's. For > >> simplicity, we do not post our results in this email. You can get very > >> detailed information in the web page listed above. > >> We are very confused by our results. We will very appreciate it if we > >> can receive your early reply. Best wishes, > >> Wang Qi > > Can you please fix your email client? > > The email text looks like one big sentence. > > > > From the perf report attached to this bugzilla, looks like RXE does a > > lot of CRC32 calculations and it is consistent with what Matan said > > a long time ago, RXE "stuck" in ICRC calculations required by spec. > > > > I'm curios what are your CONFIG_CRYPTO_* configs? > > > > ThanksCONFIG_CRYPTO_* configs > > > > > > > I'm sorry for the editor problem in my last email. Now I use another editor. Now your email has extra line between lines. > > We get our rdma-core and perftest from > > https://github.com/linux-rdma/rdma-core/archive/v25.0.tar.gz > and https://github.com/linux-rdma/perftest/archive/4.4-0.8.tar.gz, respectively. > > We attach five files to clarify our problem. > > * The first file "server_tcp_vs_softroce_performance.txt" is the results of TCP > > and softroce throughput in our two servers (connected via back to back). > > * The second file "server_CONFIG_CRYPTO_result.txt" is the > > CONFIG_CRYPTO_* config results in the two servers.. > > * The third file "server_perf.txt" is the "ib_send_bw - n 10000 192.168.0.20 > > & perf record -ags sleep 10 & wait" results in our two servers (we use > > "perf report --header >perf" to make the file). > > * The fourth file "vm_tcp_vs_softroce_performance.txt" is the results of TCP > > and softroce throughput in two virtual machines with the latest linux kernel > > 5.4.0-rc7 > > (we get the kernel from https://github.com/torvalds/linux/archive/v5.4-rc7.zip). > > * The fifth file "vm_CONFIG_CRYPTO_result.txt" is the result in two virtual > > machines. > > * The sixth file "vm_perf.txt" is the "ib_send_bw - n 10000 192.168.122.228 > > & perf record -ags sleep 10 & wait " result in the two virtual machines. > > On the other side, we tried to use the rxe command "rxe_cfg crc disable" I don't see any parsing of "crc disable" in upstream variant of rxe_cfg and there is no such module parameter in the kernel. Thanks
