Dear All,
I've been using the GTP-U kernel module to communicate with a P-GW.
Running Fedora 29, kernel 4.18.16-300.fc29.x86_64.
At high traffic levels through the GTP-U tunnel I see the performance
degrade as 100% CPU is consumed by a single ksoftirqd process.
It is running on a multi-cpu machine and as far as I can tell the load is
evenly spread across the cpus (ie either manually via smp_affinity, or even
irqbalance, checking /proc/interrupts so forth.).
Has anyone else experienced this?
Is there any particular area you could recommend I investigate to find the
root cause of this bottleneck, as i'm starting to scratch my head where to
look next...
Thanks in advance
Tony
---- FYI
modinfo gtp
filename:
/lib/modules/4.18.16-300.fc29.x86_64/kernel/drivers/net/gtp.ko.xz
alias: net-pf-16-proto-16-family-gtp
alias: rtnl-link-gtp
description: Interface driver for GTP encapsulated traffic
author: Harald Welte <hwelte(a)sysmocom.de>
license: GPL
depends: udp_tunnel
retpoline: Y
intree: Y
name: gtp
vermagic: 4.18.16-300.fc29.x86_64 SMP mod_unload
modinfo udp_tunnel
filename:
/lib/modules/4.18.16-300.fc29.x86_64/kernel/net/ipv4/udp_tunnel.ko.xz
license: GPL
depends:
retpoline: Y
intree: Y
name: udp_tunnel
vermagic: 4.18.16-300.fc29.x86_64 SMP mod_unload
