Performance issue running quest image on qemu compiled for Win32 platform

[Jacob Kroon]

I'm seeing performance issues when booting a guest image on qemu 1.4.0 compiled for the Win32 platform.
The same image boots a lot faster on the same computer running qemu/linux on Fedora via VmWare, and even running the Win32 exectuable via Wine performs better than running qemu natively on Win32.

Although I'm not the author of the image, it is located here:
http://people.freebsd.org/~wpaul/qemu/vxworks.img

All testing has been done on QEMU 1.4.0.

I'm also attaching a couple of gprof logs. For these I have disabled ssp in qemu by removing "-fstack-protector-all" and "-D_FORTIFY_SOURCE=2" from the qemu configure script.

qemu-perf-linux.txt
================
Machine - Windows XP - VmWare - Fedora - QEMU

qemu-perf-win32.txt
=================
Machine - Windows XP - QEMU

qemu-perf-wine.txt
================
Machine - Windows XP - VmWare - Fedora - Wine - QEMU

[Jacob Kroon (jacob-kroon)]

For linux, the build is done by the native Fedora 18 gcc, 4.7.2
For Win32, the build is done by Fedora 18's mingw compiler, 4.7.2

Configuration for Win32 (from config.log):
# Configured with: './configure' '--disable-guest-agent' '--disable-vnc' '--disable-werror' '--extra-cflags=-pg' '--extra-ldflags=-pg' '--target-list=i386-softmmu' '--cross-prefix=i686-w64-mingw32-'

NOTE: debug is not enabled, since it breaks current QEMU build (undefined references to 'ffs')

Configuration for Linux (from config.log):
# Configured with: './configure' '--disable-guest-agent' '--disable-vnc' '--disable-werror' '--extra-cflags=-pg' '--extra-ldflags=-pg' '--target-list=i386-softmmu' '--enable-debug' '--enable-kvm'

NOTE: although I pass --enable-kvm to configure, I haven't passed it to qemu when running the executables

Commandline for running on Win32 (started from a Cygwin terminal) and also with Fedora+Wine:
./qemu/i386-softmmu/qemu-system-i386w.exe -L qemu/pc-bios/ vxworks.img

Commandline for running on Fedora:
./qemu/i386-softmmu/qemu-system-i386 -L qemu/pc-bios/ vxworks.img

[Thomas Huth (th-huth)]

Triaging old bug tickets... can you still reproduce this issue with the latest version of QEMU and the latest version of MinGW? Do you also see the problem with the builds from https://qemu.weilnetz.de/ ? Or could we close this ticket nowadays?

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]