Hello, I have server platform S5520UR, 2x Intel Xeon E5520 with Debian Squeeze.
In kvm guest with debian, I execute gbuk for firebird and he working
quickly on 1 cpu guest, than 4.
vmstat show that with 1 cpu guest 300/s interrupts, but in 4 cpu guest
interrupts over 12000/s
If run gbuk in host than interrupts ~500/s
Why multiprocessor guest has slow performance and many "Rescheduling
interrupts"?
uname -a
Linux vm 2.6.32-5-amd64 #1 SMP Wed Jan 12 03:40:32 UTC 2011 x86_64 GNU/Linux
Hyper Threading off.
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU E5520 @ 2.27GHz
stepping : 5
cpu MHz : 2261.597
cache size : 8192 KB
physical id : 0
siblings : 4
core id : 0
cpu cores : 4
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe
syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good
xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2
ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm tpr_shadow vnmi
flexpriority ept vpid
bogomips : 4523.19
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management:
### GUEST 4 CPU & GBAK
LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
HOME=/ QEMU_AUDIO_DRV=none /usr/bin/kvm -S -M pc-0.12 -cpu
qemu64,+sse4.2,+sse4.1,+cx16,+ssse3,+ht,+ss,+acpi,-svm -enable-kvm -m
4096 -smp 4,sockets=4,cores=1,threads=1 -name firebird -uuid
e324d7cf-63e8-bece-da69-915f3b60cd4e -nodefaults -chardev
socket,id=monitor,path=/var/lib/libvirt/qemu/firebird.monitor,server,nowait
-mon chardev=monitor,mode=readline -rtc base=localtime -boot c -drive
file=/dev/mapper/infor-sys,if=none,id=drive-virtio-disk0,boot=on,format=raw,cache=none
-device virtio-blk-pci,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0
-drive file=/dev/vm3-vg0/firebird-backup,if=none,id=drive-virtio-disk1,format=raw,cache=none
-device virtio-blk-pci,bus=pci.0,addr=0x5,drive=drive-virtio-disk1,id=virtio-disk1
-drive if=none,media=cdrom,id=drive-ide0-1-0,readonly=on,format=raw
-device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0
-device rtl8139,vlan=0,id=net0,mac=00:00:00:00:00:00 -net
tap,vlan=0,name=hostnet0 -chardev pty,id=serial0 -device
isa-serial,chardev=serial0 -usb -device usb-tablet,id=input0 -vnc
127.0.0.1:0 -vga cirrus -device
virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6
vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
3 0 0 3936060 2808 50236 0 0 22 1 81 188 0 0 99 0
1 0 0 3932836 2816 52308 0 0 1024 12 10895 42583 12 12 76 0
2 0 0 3930092 2816 54200 0 0 768 0 12262 35393 9 8 83 0
1 0 0 3926992 2816 56104 0 0 896 0 12504 37866 8 16 76 0
1 0 0 3924248 2816 57896 0 0 768 0 12635 36196 11 18 71 0
2 0 0 3921488 2816 59672 0 0 768 0 12137 34850
9 13 78 0
cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3
0: 36 1 0 0 IO-APIC-edge timer
1: 0 2 3 2 IO-APIC-edge i8042
6: 0 1 0 1 IO-APIC-edge floppy
8: 0 0 0 1 IO-APIC-edge rtc0
9: 0 0 0 0 IO-APIC-fasteoi acpi
10: 6 5 5 7 IO-APIC-fasteoi
uhci_hcd:usb1
11: 0 0 0 0 IO-APIC-fasteoi virtio3
12: 30 33 30 33 IO-APIC-edge i8042
14: 0 0 0 0 IO-APIC-edge ata_piix
15: 21 20 22 21 IO-APIC-edge ata_piix
24: 0 0 0 0 PCI-MSI-edge
virtio0-config
25: 1932 1938 1946 1943 PCI-MSI-edge
virtio0-input
26: 0 0 0 1 PCI-MSI-edge
virtio0-output
27: 0 0 0 0 PCI-MSI-edge
virtio1-config
28: 598 602 614 590 PCI-MSI-edge
virtio1-requests
29: 0 0 0 0 PCI-MSI-edge
virtio2-config
30: 187 202 178 188 PCI-MSI-edge
virtio2-requests
NMI: 0 0 0 0 Non-maskable interrupts
LOC: 13408 17361 11917 10557 Local timer interrupts
SPU: 0 0 0 0 Spurious interrupts
PMI: 0 0 0 0 Performance
monitoring interrupts
PND: 0 0 0 0 Performance pending work
RES: 407852 316807 142502 53772 Rescheduling
interrupts <<<<<< quick increase
CAL: 36 32 40 42 Function call interrupts
TLB: 455 463 467 479 TLB shootdowns
TRM: 0 0 0 0 Thermal event interrupts
THR: 0 0 0 0 Threshold APIC interrupts
MCE: 0 0 0 0 Machine check exceptions
MCP: 2 2 2 2 Machine check polls
ERR: 0
MIS: 0
4xCPU
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 2
model name : QEMU Virtual CPU version 0.12.5
stepping : 3
cpu MHz : 2261.596
cache size : 4096 KB
fpu : yes
fpu_exception : yes
cpuid level : 4
wp : yes
flags : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pse36 clflush mmx fxsr sse sse2 syscall nx lm rep_good pni ssse3
cx16 popcnt hypervisor lahf_lm
bogomips : 4523.19
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management:
#### GUEST 1 CPU & GBAK
vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
2 0 0 3926912 2780 58440 0 0 529 14 96 3032 6 6 83 5
2 0 0 3922060 2780 61372 0 0 1408 0 277 30910 51 49 0 0
1 0 0 3916844 2788 64820 0 0 1408 12 281 30770 53 47 0 0
1 0 0 3912000 2788 67764 0 0 1408 0 277 30841 48 52 0 0
2 0 0 3907288 2796 70700 0 0 1408 24 285 30846 44 56 0 0
2 0 0 3902220 2796 74044 0 0 1280 0 276 30890 51 49 0 0
#### HOST 8 CPU & GBAK
vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
2 0 7168 14189732 302768 34404528 0 0 2432 24 621
107481 7 6 87 0
1 0 7168 14180556 302768 34410160 0 0 2560 6 617
110398 8 7 85 0
1 0 7168 14172124 302768 34415664 0 0 2432 2 593
111195 7 7 86 0
1 0 7168 14162452 302768 34421732 0 0 2688 0 617
116094 5 4 91 0
1 0 7168 14153524 302768 34427364 0 0 2560 0 607
116056 7 7 87 0
More stats here http://pastebin.com/vy5WtvU4
Thanks for any advice.
--
Konstantin
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