Re: [PATCH net 0/4] Revert "tun/tap & vhost-net: apply qdisc backpressure on full ptr_ring to reduce TX drops"
From: patchwork-bot+netdevbpf
Date: Wed Jul 29 2026 - 20:21:26 EST
Hello:
This series was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@xxxxxxxxxx>:
On Tue, 28 Jul 2026 11:22:36 +0200 you wrote:
> Commit 1d6e569b7d0c ("tun/tap & vhost-net: avoid ptr_ring tail-drop when
> a qdisc is present") did not show a relevant performance regression in my
> testing, but on Brett Sheffield's librecast testbed it causes a
> significant throughput drop in an IPv6 multicast testcase. The regression
> can be pinpointed to multiple iperf3 TCP threads sending: for 8 threads
> the throughput dropped from 13.5 Gbit/s to 9.13 Gbit/s.
>
> [...]
Here is the summary with links:
- [net,1/4] Revert "tun/tap & vhost-net: avoid ptr_ring tail-drop when a qdisc is present"
https://git.kernel.org/netdev/net/c/f11b48aa674b
- [net,2/4] Revert "ptr_ring: move free-space check into separate helper"
https://git.kernel.org/netdev/net/c/6bc85579c3bb
- [net,3/4] Revert "vhost-net: wake queue of tun/tap after ptr_ring consume"
https://git.kernel.org/netdev/net/c/8f83be72d9f5
- [net,4/4] Revert "tun/tap: add ptr_ring consume helper with netdev queue wakeup"
https://git.kernel.org/netdev/net/c/c3da92af07ea
You are awesome, thank you!
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