On Fri, Feb 16, 2018 at 8:33 AM, Neal Cardwell [off-list ref] wrote:
Oleksandr,
Thanks for the detailed report! Yes, this sounds like an issue in BBR. We
have not run into this one in our team, but we will try to work with you to
fix this.
Would you be able to take a sender-side tcpdump trace of the slow BBR
transfer ("v4.13 + BBR + fq_codel == Not OK")? Packet headers only would be
fine. Maybe something like:
tcpdump -w /tmp/test.pcap -c1000000 -s 100 -i eth0 port $PORT
Thanks!
neal
On baremetal and using latest net tree, I get pretty normal results at
least, on 40Gbit NIC,
with pfifo_fast, fq and fq_codel.
# tc qd replace dev eth0 root fq
# ./super_netperf 1 -H lpaa24 -- -K cubic
25627
# ./super_netperf 1 -H lpaa24 -- -K bbr
25897
# tc qd replace dev eth0 root fq_codel
# ./super_netperf 1 -H lpaa24 -- -K cubic
22246
# ./super_netperf 1 -H lpaa24 -- -K bbr
25228
# tc qd replace dev eth0 root pfifo_fast
# ./super_netperf 1 -H lpaa24 -- -K cubic
25454
# ./super_netperf 1 -H lpaa24 -- -K bbr
25508
On Fri, Feb 16, 2018 at 11:43 AM, Eric Dumazet [off-list ref] wrote:
On Fri, Feb 16, 2018 at 8:33 AM, Neal Cardwell [off-list ref] wrote:
quoted
Oleksandr,
Thanks for the detailed report! Yes, this sounds like an issue in BBR. We
have not run into this one in our team, but we will try to work with you to
fix this.
Would you be able to take a sender-side tcpdump trace of the slow BBR
transfer ("v4.13 + BBR + fq_codel == Not OK")? Packet headers only would be
fine. Maybe something like:
tcpdump -w /tmp/test.pcap -c1000000 -s 100 -i eth0 port $PORT
Thanks!
neal
On baremetal and using latest net tree, I get pretty normal results at
least, on 40Gbit NIC,
Eric raises a good question: bare metal vs VMs.
Oleksandr, your first email mentioned KVM VMs and virtio NICs. Your
second e-mail did not seem to mention if those results were for bare
metal or a VM scenario: can you please clarify the details on your
second set of tests?
Thanks!
Hi!
On pátek 16. února 2018 17:45:56 CET Neal Cardwell wrote:
Eric raises a good question: bare metal vs VMs.
Oleksandr, your first email mentioned KVM VMs and virtio NICs. Your
second e-mail did not seem to mention if those results were for bare
metal or a VM scenario: can you please clarify the details on your
second set of tests?
Ugh, so many letters simultaneously… I'll answer them one by one if you don't
mind :).
Both the first and the second set of tests were performed on 2 KVM VMs, but
from now I'll test everything using real HW only to exclude potential
influence of virtualisation. Also, as I've already pointed out, on the real HW
the difference is even bigger (~10 times).
Now, I'm going to answer other emails of yours, including the actual results
from the real HW and tcpdump output as requested.
Thanks!
Regards,
Oleksandr