Re: slow guest performance with build load, looking for ideas

[Erik Jacobson <erikj@sgi.com>]

> What is the host cpu type?  On pre-Nehalem/Barcelona processors kvm has  
> poor scalability in mmu intensive workloads like kernel builds.

Thanks for getting back to me.

Today is pretty booked but I'm going to go find a Nehalem system and try to
run similar tests to compare.  I'll post my results to this thread.

So if I understand what you're saying: best not to use kvm guests for build
servers with pre-Nehalem processors.

Both systems I used were pre-Nehalem.  Here is a cpuinfo snip from both
systems I tested on:

processor	: 7
vendor_id	: GenuineIntel
cpu family	: 6
model		: 15
model name	: Intel(R) Xeon(R) CPU           E5345  @ 2.33GHz
stepping	: 7
cpu MHz		: 2327.500
cache size	: 4096 KB
physical id	: 1
siblings	: 4
core id		: 3
cpu cores	: 4
fpu		: yes
fpu_exception	: yes
cpuid level	: 10
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 syscall nx lm constant_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr dca lahf_lm
bogomips	: 4655.14
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:


and


processor	: 7
vendor_id	: GenuineIntel
cpu family	: 6
model		: 23
model name	: Intel(R) Xeon(R) CPU           X5460  @ 3.16GHz
stepping	: 6
cpu MHz		: 3158.307
cache size	: 6144 KB
physical id	: 1
siblings	: 4
core id		: 3
cpu cores	: 4
apicid		: 7
initial apicid	: 7
fpu		: yes
fpu_exception	: yes
cpuid level	: 10
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 lahf_lm tpr_shadow vnmi flexpriority
bogomips	: 6317.51
clflush size	: 64
cache_alignment	: 64
address sizes	: 38 bits physical, 48 bits virtual
power management: