Re: [Qemu-devel] chroot to ARM Gentoo install.

[Paul Brook]

On Wednesday 25 August 2004 23:36, Fabrice Bellard wrote:
> I am curious to know what speed you get in user mode emulation.

I did some benchmarking on on a 2GHz amd64 machine running in 32-bit mode.
I don't have a real arm machine for comparison. 

I did two runs. One native (i486), the other soft-float armv4 using qemu. 

First I ran the SPECint benchmarks. These mainly stress integer CPU and memory 
performance. I'm not sure if I'm allowed to give actual results, so I'll just 
give a summary for now.

Five tests fail to execute properly. I haven't tried the executables on real 
arm hardware, so these may be compiler/libc bugs.

One test runs a mere 60% slower. The other six tests take between 3 and 7 
times as long to run.

I also ran the bonnie++ disk IO benchmark. The machine was under intermittent 
light load while the tests were run, so there's probably some variation in 
the numbers.

Native:
 1.03       ------Sequential Output------ --Sequential Input- --Random-
            -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
       Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
         4G 30667  75 31279  12 14788   5 21951  60 34922   5 161.0   0
            ------Sequential Create------ --------Random Create--------
            -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
      files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
         16  2296  98 +++++ +++ +++++ +++  2267  97 +++++ +++ 10236  99

qemu-arm:
 1.03       ------Sequential Output------ --Sequential Input- --Random-
            -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
       Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
         4G     0   0 31734  10     0   0 +++++ +++ 36888   5 167.8   0
            ------Sequential Create------ --------Random Create--------
            -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
      files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
         16  2733  97 +++++ +++ +++++ +++  2863  98 +++++ +++  9947  93

Strangely the qemu results are showing zero for per-char IO. I guess this is a 
bug somewhere. The per-char write results should be ~6000K/s

Paul