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?
- 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.
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