Hi Timo On Sun, Nov 3, 2019 at 5:12 PM txfh2007 <txfh2...@aliyun.com> wrote:
> Hi Darrell: > Sorry for my late reply. Yes, the two VMs under test are on same > compute node , and pkts rx/tx via vhost user type port. Got it > Firstly if I don't configure meter table, then Iperf TCP bandwidth result > From VM1 to VM2 is around 5Gbps, then I set the meter entry and constraint > the rate, and the deviation is larger than I throught. > IIUC, pre-meter, you get 5 Gbps, then post-meter 0.5 Gpbs, which is less than you expected ? What did you expect the metered rate to be ? Note Ben pointed you to a meter related bug fix on the alias b4. > I guess the recalculation of l4 checksum during conntrack would impact > the actual rate? > are you applying the meter rule at end of the complete pipeline ? > > Thank you > Timo > > > > > txfh2007 <txfh2...@aliyun.com> > Ben Pfaff <b...@ovn.org>; ovs-discuss <ovs-discuss@openvswitch.org> > Re: [ovs-discuss] Re:Re: [HELP] Question about icmp pkt marked Invalid by > userspace conntrack > > > Hi Timo > > > I read thru this thread to get more context on what you are doing; you > have a base OVS-DPDK > use case and are measuring VM to VM performance across 2 compute nodes. > You are probably using > vhost-user-client ports ? Pls correct me if I am wrong. > In this case, "per direction" you have one rx virtual interface to handle > in OVS; there will be a tradeoff b/w > checksum validation security and performance. > JTBC, in terms of your measurements, how did you arrive at the 5Gbps - > instrumented code or otherwise ?. > (I can verify that later when I have a setup). > > > Darrell > > > > > > > > > > > On Thu, Oct 31, 2019 at 9:23 AM Darrell Ball <dlu...@gmail.com> wrote: > > > > > On Thu, Oct 31, 2019 at 3:04 AM txfh2007 via discuss < > ovs-discuss@openvswitch.org> wrote: > > Hi Ben && Darrell: > This patch works, but after merging this patch I have found the iperf > throughout decrease from 5Gbps+ to 500Mbps. > > what is the 5Gbps number ? Is that the number with marking all packets as > invalid in initial sanity checks ? > > > Typically one wants to offload checksum checks. The code checks whether > that has been done and skips > doing it in software; can you verify that you have the capability and are > using it ? > > > Skipping checksum checks reduces security, of course, but it can be added > if there is a common case of > not being able to offload checksumming. > > > > I guess maybe we should add a switch to turn off layer4 checksum > validation when doing userspace conntrack ? I have found for kernel > conntrack, there is a related button named "nf_conntrack_checksum" . > > Any advice? > > Thank you ! > > ------------------------------------------------------------------ > > :Ben Pfaff <b...@ovn.org> > :ovs-discuss <ovs-discuss@openvswitch.org> > :Re:Re:[ovs-discuss] [HELP] Question about icmp pkt marked Invalid by > userspace conntrack > > > Hi Ben && Darrell: > Thanks, this patch works! Now the issue seems fixed > > Timo > > > Re: Re:[ovs-discuss] [HELP] Question about icmp pkt marked Invalid by > userspace conntrack > > > I see. > > It sounds like Darrell pointed out the solution, but please let me know > if it did not help. > > On Fri, Oct 11, 2019 at 08:57:58AM +0800, txfh2007 wrote: > > Hi Ben: > > > > I just found the GCC_UNALIGNED_ACCESSORS error during gdb trace and > not sure this is a misaligned error or others. What I can confirm is > during "extract_l4" of this icmp reply packet, when we do "check_l4_icmp", > the unaligned error emits and the "extract_l4" returned false. So this > packet be marked as ct_state=invalid. > > > > Thank you for your help. > > > > Timo > > > > Topic:Re: [ovs-discuss] [HELP] Question about icmp pkt marked Invalid by > userspace conntrack > > > > > > It's very surprising. > > > > Are you using a RISC architecture that insists on aligned accesses? On > > the other hand, if you are using x86-64 or some other architecture that > > ordinarily does not care, are you sure that this is about a misaligned > > access (it is more likely to simply be a bad pointer)? > > > > On Thu, Oct 10, 2019 at 10:50:33PM +0800, txfh2007 via discuss wrote: > > > > > > Hi all: > > > I was using OVS-DPDK(version 2.10-1), and I have found pinging > between two VMs on different compute nodes failed. I have checked my env > and found there is one node's NIC cannot strip CRC of a frame, the other > node's NIC is normal(I mean it can strip CRC ). And the reason of ping fail > is the icmp reply pkt (from node whose NIC cannot strip CRC) is marked as > invalid . So the icmp request From Node A is 64 bytes, but the icmp reply > From Node B is 68 bytes(with 4 bytes CRC). And when doing "check_l4_icmp", > when we call csum task(in lib/csum.c). Gcc emits unaligned accessor error. > The backtrace is as below: > > > > > > I just want to confirm if this phenomenon is reasonable? > > > > > > Many thanks > > > > > > Timo > > > > > > > > > get_unaligned_be16 (p=0x7f2ad0b1ed5c) at lib/unaligned.h:89 > > > 89 GCC_UNALIGNED_ACCESSORS(ovs_be16, be16); > > > (gdb) bt > > > #0 get_unaligned_be16 (p=0x7f2ad0b1ed5c) at lib/unaligned.h:89 > > > #1 0x000000000075a584 in csum_continue (partial=0, > data_=0x7f2ad0b1ed5c, n=68) at lib/csum.c:46 > > > #2 0x000000000075a552 in csum (data=0x7f2ad0b1ed5c, n=68) at > lib/csum.c:33 > > > #3 0x00000000008ddf18 in check_l4_icmp (data=0x7f2ad0b1ed5c, size=68, > validate_checksum=true) at lib/conntrack.c:1638 > > > #4 0x00000000008de650 in extract_l4 (key=0x7f32a20df120, > data=0x7f2ad0b1ed5c, size=68, related=0x7f32a20df15d, l3=0x7f2ad0b1ed48, > > > validate_checksum=true) at lib/conntrack.c:1888 > > > #5 0x00000000008de90d in conn_key_extract (ct=0x7f32b42a2d98, > pkt=0x7f2ad0b1e9c0, dl_type=8, ctx=0x7f32a20df120, zone=4) > > > at lib/conntrack.c:1973 > > > #6 0x00000000008dd49c in conntrack_execute (ct=0x7f32b42a2d98, > pkt_batch=0x7f32a20e08b0, dl_type=8, force=false, commit=false, > > > zone=4, setmark=0x0, setlabel=0x0, tp_src=0, tp_dst=0, helper=0x0, > nat_action_info=0x0, now=5395897849) at lib/conntrack.c:1318 > > > #7 0x000000000076d651 in dp_execute_cb (aux_=0x7f32a20dfb00, > packets_=0x7f32a20e08b0, a=0x7f32a20e0ac8, should_steal=false) > > > at lib/dpif-netdev.c:6711 > > > #8 0x00000000007b2d49 in odp_execute_actions (dp=0x7f32a20dfb00, > batch=0x7f32a20e08b0, steal=true, actions=0x7f32a20e0ac8, > > > actions_len=20, dp_execute_action=0x76ca60 <dp_execute_cb>) at > lib/odp-execute.c:726 > > > #9 0x000000000076d71b in dp_netdev_execute_actions > (pmd=0x7f2a6e1ce010, packets=0x7f32a20e08b0, should_steal=true, > > > flow=0x7f32a20dfb60, actions=0x7f32a20e0ac8, actions_len=20) at > lib/dpif-netdev.c:6754 > > > #10 0x000000000076b900 in handle_packet_upcall (pmd=0x7f2a6e1ce010, > packet=0x7f2ad0b1e9c0, key=0x7f32a20e1100, > > > actions=0x7f32a20e0a40, put_actions=0x7f32a20e0a80) at > lib/dpif-netdev.c:6056 > > > #11 0x000000000076bdf0 in fast_path_processing (pmd=0x7f2a6e1ce010, > packets_=0x7f32a20e2b60, keys=0x7f32a20e10c0, > > > batches=0x7f32a20e0f90, n_batches=0x7f32a20e13c0, in_port=15) at > lib/dpif-netdev.c:6153 > > > #12 0x000000000076c3df in dp_netdev_input__ (pmd=0x7f2a6e1ce010, > packets=0x7f32a20e2b60, md_is_valid=true, port_no=0) > > > at lib/dpif-netdev.c:6230 > > > #13 0x000000000076c4d4 in dp_netdev_recirculate (pmd=0x7f2a6e1ce010, > packets=0x7f32a20e2b60) at lib/dpif-netdev.c:6265 > > > #14 0x000000000076ceae in dp_execute_cb (aux_=0x7f32a20e1db0, > packets_=0x7f32a20e2b60, a=0x7f32a20e2d78, should_steal=true) > > > > > > > > > _______________________________________________ > > > discuss mailing list > > > disc...@openvswitch.org > > > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss > > > > > > _______________________________________________ > discuss mailing list > disc...@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss > > > > > > >
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