On Thu, Jul 11, 2013 at 02:52:40PM +0200, Victor fernandez wrote: > Hi Gleb, > > you were right, we update the qemu-kvm to 1.0 and now > the S.L. instance start with new cpu flags (for instance: > 3dnowext,3dnow). > > But we have bad performance still, around 17% of lost in > our AMD processors. Let me explain better, we are running > three different hight energy physic softwares. And in 2 of them > we don't have any problem with the performances, 4-5% of lost. > But in the other one (GAUSS, LHCb software), and only in > AMD-V virtualization we have arount 17%-33% lost performance > depending on the processor number. But Gauss software in > Intel processor are running with an acceptable performance. > > And we suspected that could be due to cpu flags, but now we are not > sure about that because now 3dnowext,3dnow are included > and the performances are still bad. But these flags are not yet > included > with qemu-kvm_1.0. > > > ht > rdtscp > constant_tsc > nopl > nonstop_tsc > amd_dcm > > monitor > extapic > ibs > skinit > wdt > nodeid_msr > hw_pstate > > lbrv > svm_lock > pausefilter > > - Do you think that these flags could be the problem? Non of them are related to an instruction set relevant for performance. amd_dcm is a synthetic flag (meaning that it does not correspond to any real cpuid) that says that your machine is NUMA. Can you bind you VM to single numa node with taskset/numactl? I see that you assign only 2G to your VM, may be this is not enough? How much memory host has? > - Do you have any idea what could it be? > > Thanks in advance Gleb, > Víctor Fdez. > > > El 09/07/13 18:08, Gleb Natapov escribió: > >On Tue, Jul 09, 2013 at 05:30:26PM +0200, Victor fernandez wrote: > >>Hi Gleb, > >> > >> root@vfalbor-desktop:~# uname -a > >>*Linux vfalbor-desktop 2.6.32-24-generic *#43-Ubuntu SMP Thu Sep 16 > >>14:58:24 UTC 2010 x86_64 GNU/Linux > >> > >> root@vfalbor-desktop:~# dpkg --list | grep qemu > >> ii qemu-common *0.12.3+noroms-0ubuntu9.21 * qemu common > >>functionality (bios, documentati > >> ri qemu-kvm *0.12.3+noroms-0ubuntu9.21* > >>Full virtualization on i386 and amd64 hardwa > >> > >Ugh, those are ancient and vendor packages. I thought you were running > >Scientific Linux 6 as a host too which also has vendor specific > >packages, but at least something that I can easily look into :) > >Can you reproduce with upstream kernel/qemu? If it works on upstream you > >can open bug in Ubuntu. > > > >> One of the things that we did, we try to update libvirt to the > >>last versions > >> because we are using for our cloud the version of ubuntu 10.04 and the > >> last stable version of libvirt was 0.7.5-5ubuntu27.23, but when > >>we try to > >> get the capabilities, we get the following: > >This is definitely not libvirt fault. This is either kernel or qemu. > >Looking into git history 3dnow/3dnowext support was introduce into the > >kernel kvm component before 2.6.32 though. > > > >> root@vfalbor-desktop:~/# virsh capabilities | grep 3dnow > >> <feature name='*3dnowprefetch*'/> > >> root@vfalbor-desktop:~/# > >> > >> but in the cpu_map.xml file we find the 3dnow and 3dnowext for > >>our architecture: > >> > >> root@vfalbor-desktop:~/# cat /usr/share/libvirt/cpu_map.xml | > >>grep 3dnow > >> <feature name='*3dnowext*'> <!-- CPUID_EXT2_3DNOWEXT --> > >> <feature name='3dnow'> <!-- CPUID_EXT2_3DNOW --> > >> <feature name='3dnowprefetch'> <!-- > >>CPUID_EXT3_3DNOWPREFETCH --> > >> > >> Thanks Gleb, > >> Víctor Fdez. > >> > >>El 09/07/13 17:16, Gleb Natapov escribió: > >>>On Tue, Jul 09, 2013 at 05:07:57PM +0200, Victor fernandez wrote: > >>>>Yep, > >>>> > >>>> -> this is for the host: > >>>> > >>>> root@vfalbor-desktop:~# cat /proc/cpuinfo | grep flags | uniq > >>>> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr > >>>>pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx > >>>>mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc > >>>>rep_good nonstop_tsc extd_apicid amd_dcm pni monitor cx16 popcnt > >>>>lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse > >>>>3dnowprefetch osvw ibs skinit wdt nodeid_msr > >>>> > >>>> -> this is for the VM: > >>>> [root@sl6 ~]# cat /proc/cpuinfo | grep flags | uniq > >>>> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr > >>>>pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext > >>>>fxsr_opt pdpe1gb lm rep_good extd_apicid pni cx16 popcnt lahf_lm > >>>>cmp_legacy cr8_legacy abm sse4a misalignsse 3dnowprefetch > >>>> > >>>Hmm, what is your kernel and qemu versions? > >>> > >>>>El 09/07/13 17:00, Gleb Natapov escribió: > >>>>>On Tue, Jul 09, 2013 at 04:57:13PM +0200, Victor fernandez wrote: > >>>>>> 2.- with the "-cpu host" parameter: > >>>>>> > >>>>>>/usr/bin/kvm *-cpu host* -m 2048 -smp 1 -name i-2-11-VM -monitor > >>>>>>telnet:127.0.0.1:9941,server,nowait -boot c /mnt/b07f7f29-7b9b-3d4b-b170-77876d10e7b1/134bc689-1207-487c-ae95-6c0dc2e0f285 > >>>>>>-parallel none -usb -usbdevice tablet -vnc :0 -vga cirrus -net > >>>>>>nic,macaddr=06:00:90:00:00:08,vlan=0,model=e1000,name=e1000.0 -net > >>>>>>tap,script=/usr/bin/qemu-ifup,vlan=0,name=tap.0 > >>>>>> > >>>>>With this command line can you provide output of /proc/cpuinfo on the > >>>>>host and the guest? > >>>>> > >>>>>-- > >>>>> Gleb. > >>>>>-- > >>>>>To unsubscribe from this list: send the line "unsubscribe kvm" in > >>>>>the body of a message to majordomo@xxxxxxxxxxxxxxx > >>>>>More majordomo info at http://vger.kernel.org/majordomo-info.html > >>>-- > >>> Gleb. > >-- > > Gleb. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
