Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 13 Feb 2020 18:58:53 -0800
From:      Brian Buhrow <buhrow@nfbcal.org>
To:        freebsd-xen@freebsd.org
Subject:   Slow networking speeds with Freebsd 12.0 and Xen-4.12.1, freebsd-12.0 as dom0
Message-ID:  <202002140258.01E2wrpj018654@lothlorien.nfbcal.org>

next in thread | raw e-mail | index | archive | help
	Hello.  I'm noticing that network performance on guest VN's whether
they're pv or hvm is very slow when using FreeBSD-12.0 as dom0 as compared
with older versions of Xen and NetBSD as dom0.  For example, 
I have the following two comparisons, both with the same domu running:

FreeBSD-12.0/Xen 4.12.1, 60 mbits/sec from the vm in question.

NetBSD-5.2/xen 3.3, 781 mbits/sec with the same vm as above.

The NetBSD installation is running single CPU for the dom0, with 4GB of
RAM, as opposed to FreeBSD, which is running 8GB of RAM and 4 CPU's.
By contrast, disk performance under FreeBSD using zfs zvols' as virtual
disks is quite fast.  

	As a work around, I tried turning on msi interrupt handling on dom0 on
FreeBSD, using msi=false on the xen command line at boot time, but that
only resulted in a panic from FreeBSD because it couldn't get enough disk
interrupts to mount the root filesystem.

	Has anyone else noticed this abysmal network performance with
FreeBSD-12 as dom0?
If so, has anyone come up with fixes?
-thanks
-Brian




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202002140258.01E2wrpj018654>