Date: Sat, 4 Apr 2015 17:12:31 +0200 From: Rainer Duffner <rainer@ultra-secure.de> To: Andrew Daugherity <adaugherity@tamu.edu> Cc: "freebsd-xen@freebsd.org" <freebsd-xen@freebsd.org> Subject: Re: Poor performance with FreeBSD 10.1 under Xen 4.2 Message-ID: <C7E1602C-DAB4-4612-9D16-5CE5385AED92@ultra-secure.de> In-Reply-To: <5CC2ABAB-AE46-4C9F-A610-D4EAD735ECA0@tamu.edu> References: <115BE54D-078A-4C45-8904-861DAB316C03@tamu.edu> <5516A998.10206@citrix.com> <57429F3F-8CC9-4C4F-86DF-3E63C5853B01@tamu.edu> <5CC2ABAB-AE46-4C9F-A610-D4EAD735ECA0@tamu.edu>
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> Am 02.04.2015 um 19:58 schrieb Andrew Daugherity = <adaugherity@tamu.edu>: >=20 > On Mar 30, 2015, at 6:52 PM, Andrew Daugherity <adaugherity@tamu.edu> = wrote: >> On Mar 28, 2015, at 8:16 AM, Roger Pau Monn=E9 <roger.pau@citrix.com> = wrote: >>> I'm Ccing feld because IIRC he found something similar on one of his >>> boxes, that also had VTx but no EPT (just like yours). Would it be >>> possible for you to try the same set of tests on a different = hardware? >>=20 >> I think you're on to something. I copied this FreeBSD 10.1 VM to a = system running the same version of Xen (and same SLES in the Dom0), but = with an Opteron 2360SE CPU (which has both SVM and NPT), and it is = *much* faster (and feels more responsive too): >> [snip] >>> Also, if even FreeBSD 10.1 compiled without XENHVM shows this issue = it >>> means there's something in the generic code that doesn't work well = when >>> running virtualized on this specific hardware, but I'm afraid = figuring >>> it out is not trivial. One place to start would be asking on >>> freebsd-hackers and freebsd-virt. >>=20 >> I suppose this performance delta with presence of EPT/NPT vs. lack = thereof means it's time to take it to those lists? My next step will be = to test 10.1 under KVM on the Xeon to confirm whether it's a Xen issue = or strictly EPT. >=20 > It seems I spoke too soon. I booted into the "default" (non-Xen) = Linux kernel on the Xeon E5420 box and launched the same FreeBSD 10.1 VM = under KVM, and performance is much, much better: >=20 Hi, I have access to Xen at work (and will continue to do so - we intend to = use and offer FreeBSD in our =84Cloud=93-platform (Apache CloudStack). AFAIK, we have no KVM. Just Xen. Unfortunately, I=92ve got little time currently, but I will try to get a = VM where I can run this during the next week. I will also collect the hardware-details of the host (AFAIK, we=92ve got = HP DL380G8 servers with lots of RAM and two CPUs). Rainer
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