From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Venefax" Subject: RE: Windows SMP Date: Mon, 5 Jan 2009 15:11:06 -0500 Message-ID: <03e801c96f71$bec1a880$3c44f980$@com> References: <069e01c96b55$3c834d80$b589e880$@com> <4962588D.7080204@virtualiron.com> <03d101c96f68$eec4da10$cc4e8e30$@com> <496267EF.5070508@virtualiron.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <496267EF.5070508@virtualiron.com> Content-Language: en-us List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: 'Steve Ofsthun' Cc: xen-devel@lists.xensource.com, 'Andrew Lyon' , 'Dirk Utterback' , 'Keir Fraser' , 'James Harper' List-Id: xen-devel@lists.xenproject.org I am using two version of the drivers, with identical limitations. = James' GPLPV and the Novell drivers. Federico -----Original Message----- From: Steve Ofsthun [mailto:sofsthun@virtualiron.com]=20 Sent: Monday, January 05, 2009 3:05 PM To: Venefax Cc: 'Keir Fraser'; 'Andrew Lyon'; 'James Harper'; 'Dirk Utterback'; = xen-devel@lists.xensource.com Subject: Re: [Xen-devel] Windows SMP Venefax wrote: > I use only Windows 2003 R2 SP2 fully patched. Therefore that patch = would not apply since it is for Vista (Novell shim (Vista/2008 guests). = But I will ask Novell. > I would love to try that second patch that would "force all guest = callback interrupts to VCPU 0". My setup is to use one core for xen, = only, and the rest 15 cores for virtual machines, as instructed by = Novell support. I am not over-committing CPU's. Even if I run one single = virtual machine with 8 CPU's, the performance is awful. It takes 10 = mins to load an application that loads in 1.5-2.0 mins with one single = CPU. I switched all my 16 virtual machines to Standard PC Hal and that = is the only way that the application works. However, it is an = administrative nightmare. Instead of managing 16 independent windows = machines via VNC, I should be able to manage two, maybe one. > Can you send me information regarding both patches mentioned? I'll have to check into the state of the PAUSE exit patch. We are doing = the work on an Intel Tylersburg machine. I don't think these are = generally available yet. I have attached the referenced callback IRQ routing patch. Whose Windows PV-on-HVM drivers are you running? Steve > Federico >=20 >=20 > -----Original Message----- > From: Steve Ofsthun [mailto:sofsthun@virtualiron.com] > Sent: Monday, January 05, 2009 1:59 PM > To: Venefax > Cc: 'Keir Fraser'; 'Andrew Lyon'; 'James Harper'; 'Dirk Utterback';=20 > xen-devel@lists.xensource.com > Subject: Re: [Xen-devel] Windows SMP >=20 > Venefax wrote: >> Dear Gentlemen >=20 >> I have a machine with Intel 7350, 4 quad core. I can test since I=20 >> have two virtual machines with 8 vcpus, showing a gross overhead that = >> makes them unsuited for business. I use SLES 10 SP2, and I don't know = >> how to apply the patch, but if somebody can log in and apply it, we=20 >> can see the results immediately. The issue is affecting me directly.=20 >> My two VM's have a VOIP application, very intensive in network and = CPU usage. >=20 > If your problem isn't the previously discussed TPR issues ... >=20 > What Windows version are you running in your guests? >=20 > Windows 2000 SMP has serious problems due to the CPU wasting idle = loop. We avoid this with a special idler daemon running in the guest. >=20 >=20 > Are you over-committing VCPUS at all (more than one active VCPU per = CPU)? >=20 > We have noticed significant performance degradation with SMP windows = once you over-commit VCPUS on the host. This seems to be due to = excessive guest spinlock overhead caused by the spinning VCPUS wasting = their entire quantum looping for the guest lock at the same time they = are preventing the guest lock holding VCPU from running. We have been = experimenting with new CPU features for exiting on PAUSE instructions. = This can possibly be used to detect the CPU wasting spinners. >=20 >=20 > Have you tried using the Novell shim (Vista/2008 guests)? >=20 > I'm not sure the shim provides locking enhancements, but we have seen = benefits for certain workloads. >=20 >=20 > Are you running PV on HVM drivers? >=20 > One last area of concern may be distributing callback interrupts to = all VCPUS. We still run Xen (SLES10 SP2 based) with a patch to force = all guest callback interrupts to VCPU 0. This has consistently improved = our SMP guest I/O performance while running PV-on-HVM drivers. >=20 >=20 > Steve >=20 >> Federico >> -----Original Message----- >> From: Keir Fraser [mailto:keir.fraser@eu.citrix.com] >> Sent: Wednesday, December 31, 2008 5:10 AM >> To: Andrew Lyon >> Cc: Venefax; James Harper; Dirk Utterback;=20 >> xen-devel@lists.xensource.com >> Subject: Re: [Xen-devel] Windows SMP >> >> On 31/12/2008 10:08, "Andrew Lyon" wrote: >> >>> Thanks Keir, I added a couple of printk's as you suggested and I can = >>> now see if the feature is supported: >>> >>> Intel(R) Xeon(R) CPU E5420 @ 2.50GHz =3D (XEN) APIC = Access >>> virtualized >>> Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz =3D (XEN) APIC = Access >> emulated >>> I didnt expect my Xeon system to support it, I've read some pdf's=20 >>> about Intel virtualizaton features and they seemed to suggest it was = >>> a new feature on 7xxx Xeons. >>> >>> The results fit the performance I've seen, a windows xp 32 bit hvm=20 >>> with 2 cpu's runs a lot faster on the Xeon 2.5 than on the Core 2.4. >> I think it is probably worth printing out. I'll add a patch to = xen-unstable. >> >> Thanks, >> Keir >> >> >> >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@lists.xensource.com >> http://lists.xensource.com/xen-devel >=20