nfe taskq performance issues
psteele at webmail.maxiscale.com
Thu Jul 23 16:27:20 UTC 2009
We've been hitting serious nfe taskq performance issues during stress
tests and in doing some research on the problem we came across this old
From: Ivan Voras <ivoras at freebsd.org>
Date: April 28, 2009 3:53:14 AM PDT
To: freebsd-threads at freebsd.org
Cc: freebsd-net at freebsd.org, freebsd-performance at freebsd.org
Subject: Re: FreeBSD 7.1 taskq em performance
> I have been hitting some barrier with FreeBSD 7.1 network performance.
> have written an application which contains two kernel threads that
> mbufs directly from a network interface and forwards to another
> interface. This idea is to simulate different network environment.
> I have been using FreeBSD 6.4 amd64 and tested with an Ixia box
> (specialised hardware firing very high packet rate). The PC was a
> GHz with dual ports Intel PCIE Gigabit network card. It can manage up
> million pps.
> I have a higher spec PC with FreeBSD 7.1 amd64 and Quadcore 2.3 GHz
> PCIE Gigabit network card. The performance can only achieve up to 600k
> I notice the 'taskq em0' and 'taskq em1' is solid 100% CPU but it is
> FreeBSD 6.4.
In our case we are running FreeBSD 7.0, but we are seeing our boxes
experience serious thread starvation issues as the nfe0 cpu percentage
climbs steadily while cpu idle time drops at times to 0 percent. This
email thread mentioned a patch for the em driver here:
Does anyone know if this patch will work with the nfe driver?
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