[Qemu-devel] Performance difference between QEMU 2.2.0 and 2.6.0

[Wenwen Wang]

Hello all,

I just found that there is a significant performance difference between
QEMU version 2.2.0 and 2.6.0.

Here are the execution times of the benchmark 458.sjeng from SPEC CINT2006
with test workload using user only emulation from ARM guest to x86-32 host:

qemu-2.2.0: 29 seconds
qemu-2.6.0: 38 seconds

I am sure that the evaluation environments are the same in the two
executions.

I also evaluated other benchmarks, it seems that they also have some
performance differences.

Could anyone tell me what this difference comes from or give me any hint?

Many thanks in advance!

Wenwen