Comment 23 for bug 1100843

C Cormier (ccormier) wrote :

I did some tests using Raring Server Beta 2. There are some interesting results for this test the results are mixing. Using different machine types produces different results. At this time i've only ran these simple "lat_syscall" tests from lmbench and haven't run some of the more exhaustive benchmarks or compilations.

Summary of the "lat_syscall" results using different machine types of qemu-kvm:
pc-1.0 - affected
pc-1.1 - normal
pc-1.2 - affected
pc-1.3 - affected
pc-i440fx-1.4 - normal

Test Setup

Hypervisor
OS: Raring Beta2
qemu: 1.4.0+dfsg-1expubuntu4
Kernel: 3.8.0-16-generic

Guest:
OS: Ubuntu 12.04.02 Minimal install using ubuntu-vmbuilder

LMBench results for lat syscall tests
---machine type pc-1.0---
-PRESAVE-
Simple read: 0.1301 microseconds
Simple write: 0.1052 microseconds
Simple open/close: 1.3819 microseconds
-POSTRESTORE-
Simple read: 0.2699 microseconds
Simple write: 0.2401 microseconds
Simple open/close: 1.4112 microseconds

---machine type pc-1.1---
-PRESAVE-
Simple read: 0.1265 microseconds
Simple write: 0.1033 microseconds
Simple open/close: 1.2974 microseconds
-POSTRESTORE-
Simple read: 0.1266 microseconds
Simple write: 0.1042 microseconds
Simple open/close: 1.2093 microseconds

---machine type pc-1.2---
-PRESAVE-
Simple syscall: 0.0484 microseconds
Simple read: 0.1291 microseconds
Simple write: 0.1042 microseconds
Simple open/close: 1.2501 microseconds
-POSTRESTORE-
Simple syscall: 0.0485 microseconds
Simple read: 0.2737 microseconds
Simple write: 0.2414 microseconds
Simple open/close: 1.3953 microseconds

---machine type pc-1.3---
-PRESAVE-
Simple read: 0.1276 microseconds
Simple write: 0.1101 microseconds
Simple open/close: 1.1501 microseconds
-POSTRESTORE-
Simple read: 0.2717 microseconds
Simple write: 0.2415 microseconds
Simple open/close: 1.3997 microseconds

---machine type pc-i440fx-1.4---
-PRESAVE-
Simple read: 0.1291 microseconds
Simple write: 0.1039 microseconds
Simple open/close: 1.2344 microseconds
-POSTRESTORE-
Simple read: 0.1335 microseconds
Simple write: 0.1080 microseconds
Simple open/close: 1.0453 microseconds