Re: strange guest slowness after some time

[Tomasz Chmielewski <mangoo@wpkg.org>]

Avi Kivity schrieb:

> I'm guessing there's a problem with timers or timer interrupts.
> 
> What is the host cpu?

4 entries like this in /proc/cpuinfo:

processor       : 3
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 65
model name      : Dual-Core AMD Opteron(tm) Processor 2212
stepping        : 2
cpu MHz         : 2000.000
cache size      : 1024 KB
physical id     : 1
siblings        : 2
core id         : 1
cpu cores       : 2
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
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 rdtscp lm3dnowext 3dnow rep_good pni cx16 lahf_lm cmp_legacy 
svm extapic cr8_legacy
bogomips        : 3993.03
TLB size        : 1024 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management: ts fid vid ttp tm stc


> Does the problem occur if you pin a guest to a cpu with taskset?

Like this?

# taskset -p 01 22906

(doesn't help)


# taskset -p 02 22906

(doesn't help)


But if I do:

# taskset -p 03 22906

or

# taskset -p 04 22906

it fixes it _rarely_ for the first few seconds, then it's broken again, 
until I switch the CPUs again (look at ping 9 and 10; other pings are 
also slow, unaffected guests are around 1 ms):

# ping -c 10 192.168.113.85
PING 192.168.113.85 (192.168.113.85) 56(84) bytes of data.
64 bytes from 192.168.113.85: icmp_seq=1 ttl=64 time=22.0 ms
64 bytes from 192.168.113.85: icmp_seq=2 ttl=64 time=23.7 ms
64 bytes from 192.168.113.85: icmp_seq=3 ttl=64 time=2.96 ms
64 bytes from 192.168.113.85: icmp_seq=4 ttl=64 time=51.3 ms
64 bytes from 192.168.113.85: icmp_seq=5 ttl=64 time=22.2 ms
64 bytes from 192.168.113.85: icmp_seq=6 ttl=64 time=1.60 ms
64 bytes from 192.168.113.85: icmp_seq=7 ttl=64 time=49.8 ms
64 bytes from 192.168.113.85: icmp_seq=8 ttl=64 time=23.3 ms
64 bytes from 192.168.113.85: icmp_seq=9 ttl=64 time=999 ms
64 bytes from 192.168.113.85: icmp_seq=10 ttl=64 time=822 ms


-- 
Tomasz Chmielewski
http://wpkg.org