Re: TCP and BBR: reproducibly low cwnd and bandwidth

Hi. On pátek 16. února 2018 17:25:58 CET Eric Dumazet wrote: > The way TCP pacing works, it defaults to internal pacing using a hint > stored in the socket. > > If you change the qdisc while flow is alive, result could be unexpected. I don't change a qdisc while flow is alive. Either the VM is

Re: TCP and BBR: reproducibly low cwnd and bandwidth

Hi. On pátek 16. února 2018 17:25:58 CET Eric Dumazet wrote: > The way TCP pacing works, it defaults to internal pacing using a hint > stored in the socket. > > If you change the qdisc while flow is alive, result could be unexpected. I don't change a qdisc while flow is alive. Either the VM is

Re: TCP and BBR: reproducibly low cwnd and bandwidth

Hi. On pátek 16. února 2018 17:26:11 CET Holger Hoffstätte wrote: > These are very odd configurations. :) > Non-preempt/100 might well be too slow, whereas PREEMPT/1000 might simply > have too much overhead. Since the pacing is based on hrtimers, should HZ matter at all? Even if so, poor 1 Gbps

Re: TCP and BBR: reproducibly low cwnd and bandwidth

Hi. On pátek 16. února 2018 17:26:11 CET Holger Hoffstätte wrote: > These are very odd configurations. :) > Non-preempt/100 might well be too slow, whereas PREEMPT/1000 might simply > have too much overhead. Since the pacing is based on hrtimers, should HZ matter at all? Even if so, poor 1 Gbps

Re: TCP and BBR: reproducibly low cwnd and bandwidth

On 02/16/18 17:56, Neal Cardwell wrote: > On Fri, Feb 16, 2018 at 11:26 AM, Holger Hoffstätte > wrote: >> >> BBR in general will run with lower cwnd than e.g. Cubic or others. >> That's a feature and necessary for WAN transfers. > > Please note that there's no

Re: TCP and BBR: reproducibly low cwnd and bandwidth

On 02/16/18 17:56, Neal Cardwell wrote: > On Fri, Feb 16, 2018 at 11:26 AM, Holger Hoffstätte > wrote: >> >> BBR in general will run with lower cwnd than e.g. Cubic or others. >> That's a feature and necessary for WAN transfers. > > Please note that there's no general rule about whether BBR will

Re: TCP and BBR: reproducibly low cwnd and bandwidth

On Fri, Feb 16, 2018 at 11:26 AM, Holger Hoffstätte wrote: > > BBR in general will run with lower cwnd than e.g. Cubic or others. > That's a feature and necessary for WAN transfers. Please note that there's no general rule about whether BBR will run with a lower or

Re: TCP and BBR: reproducibly low cwnd and bandwidth

On Fri, Feb 16, 2018 at 11:26 AM, Holger Hoffstätte wrote: > > BBR in general will run with lower cwnd than e.g. Cubic or others. > That's a feature and necessary for WAN transfers. Please note that there's no general rule about whether BBR will run with a lower or higher cwnd than CUBIC, Reno,

Re: TCP and BBR: reproducibly low cwnd and bandwidth

On 02/16/18 16:15, Oleksandr Natalenko wrote: > Hi, David, Eric, Neal et al. > > On čtvrtek 15. února 2018 21:42:26 CET Oleksandr Natalenko wrote: >> I've faced an issue with a limited TCP bandwidth between my laptop and a >> server in my 1 Gbps LAN while using BBR as a congestion control

Re: TCP and BBR: reproducibly low cwnd and bandwidth

On 02/16/18 16:15, Oleksandr Natalenko wrote: > Hi, David, Eric, Neal et al. > > On čtvrtek 15. února 2018 21:42:26 CET Oleksandr Natalenko wrote: >> I've faced an issue with a limited TCP bandwidth between my laptop and a >> server in my 1 Gbps LAN while using BBR as a congestion control

Re: TCP and BBR: reproducibly low cwnd and bandwidth

On Fri, Feb 16, 2018 at 7:15 AM, Oleksandr Natalenko wrote: > Hi, David, Eric, Neal et al. > > On čtvrtek 15. února 2018 21:42:26 CET Oleksandr Natalenko wrote: >> I've faced an issue with a limited TCP bandwidth between my laptop and a >> server in my 1 Gbps LAN while

Re: TCP and BBR: reproducibly low cwnd and bandwidth

On Fri, Feb 16, 2018 at 7:15 AM, Oleksandr Natalenko wrote: > Hi, David, Eric, Neal et al. > > On čtvrtek 15. února 2018 21:42:26 CET Oleksandr Natalenko wrote: >> I've faced an issue with a limited TCP bandwidth between my laptop and a >> server in my 1 Gbps LAN while using BBR as a congestion

Re: TCP and BBR: reproducibly low cwnd and bandwidth

Hi, David, Eric, Neal et al. On čtvrtek 15. února 2018 21:42:26 CET Oleksandr Natalenko wrote: > I've faced an issue with a limited TCP bandwidth between my laptop and a > server in my 1 Gbps LAN while using BBR as a congestion control mechanism. > To verify my observations, I've set up 2 KVM VMs

Re: TCP and BBR: reproducibly low cwnd and bandwidth

Hi, David, Eric, Neal et al. On čtvrtek 15. února 2018 21:42:26 CET Oleksandr Natalenko wrote: > I've faced an issue with a limited TCP bandwidth between my laptop and a > server in my 1 Gbps LAN while using BBR as a congestion control mechanism. > To verify my observations, I've set up 2 KVM VMs

TCP and BBR: reproducibly low cwnd and bandwidth

Hello. I've faced an issue with a limited TCP bandwidth between my laptop and a server in my 1 Gbps LAN while using BBR as a congestion control mechanism. To verify my observations, I've set up 2 KVM VMs with the following parameters: 1) Linux v4.15.3 2) virtio NICs 3) 128 MiB of RAM 4) 2

TCP and BBR: reproducibly low cwnd and bandwidth

Hello. I've faced an issue with a limited TCP bandwidth between my laptop and a server in my 1 Gbps LAN while using BBR as a congestion control mechanism. To verify my observations, I've set up 2 KVM VMs with the following parameters: 1) Linux v4.15.3 2) virtio NICs 3) 128 MiB of RAM 4) 2