[Qemu-devel] Re: qemu svn r5281 on FreeBSD - slow usb, vmwarevga, screen updates... (now updated to r5313)

[Matt <datahead4@gmail.com>]

On Wed, Sep 24, 2008 at 5:10 PM, Juergen Lock <nox@jelal.kn-bremen.de> wrote:
>
> In article <cd6b4a5b0809230639x27e94477k315796c2cfb650f2@mail.gmail.com> you write:
> >On Sun, Sep 21, 2008 at 3:40 PM, Juergen Lock <nox@jelal.kn-bremen.de> wrote:
> >> Hi!
> >>
> >>  I've been playing with qemu svn on FreeBSD again (new experimental
> >> emulators/qemu-devel port update here:
> >>        http://people.freebsd.org/~nox/qemu/qemu-devel-20080921.patch
> >> ), and want to note a few things:
> >
> >Hi.  I've built an updated port with your patch and it compiles fine
> >and runs my WinXP guests well.  But, the qemu process consumes 100% of
> >one CPU core on the host the whole time it is running, regardless of
> >what the guest is doing.  The host is a 7-STABLE box from 8/19.  The
> >guests run with bridged networking and full kernel kqemu accel
> >enabled.
> >
> Hmm.  And you didn't see this with the version in ports?  Have you
> checked if this is related to kqemu? (try without -kernel-kqemu and
> also with -no-kqemu.)  Also, which threading libs and scheduler are you
> using?  There seems to be an issue with kse, tho I doubt you are using
> that on 7-stable...

It does appear that this continual CPU-usage was kqemu-related.  When
booting the guest with the "-no-kqemu" option, the CPU usage on the
host was as expected and tracked with the usage in the guest.  Any
level (user or user + kernel) of kqemu accel seemed to trigger the
host to consume 100% CPU regardless of guest activity.

I use the ULE scheduler and libthr threading library.  See console output below.

]$ sysctl kern.sched.name
kern.sched.name: ULE

$ ldd /usr/local/bin/qemu
/usr/local/bin/qemu:
        libm.so.5 => /lib/libm.so.5 (0x101ad000)
        libz.so.4 => /lib/libz.so.4 (0x101c2000)
        libgnutls.so.26 => /usr/local/lib/libgnutls.so.26 (0x101d4000)
        libpcap.so.5 => /lib/libpcap.so.5 (0x1027b000)
        libutil.so.7 => /lib/libutil.so.7 (0x102a2000)
        libSDL-1.2.so.11 => /usr/local/lib/libSDL-1.2.so.11 (0x102b0000)
        libncurses.so.7 => /lib/libncurses.so.7 (0x10319000)
        libthr.so.3 => /lib/libthr.so.3 (0x10361000)
        libc.so.7 => /lib/libc.so.7 (0x10374000)
        libgcrypt.so.15 => /usr/local/lib/libgcrypt.so.15 (0x10473000)
        libgpg-error.so.0 => /usr/local/lib/libgpg-error.so.0 (0x104db000)
        libintl.so.8 => /usr/local/lib/libintl.so.8 (0x104df000)
        libiconv.so.3 => /usr/local/lib/libiconv.so.3 (0x104e8000)
        libvgl.so.5 => /usr/lib/libvgl.so.5 (0x105de000)
        libaa.so.1 => /usr/local/lib/libaa.so.1 (0x105e6000)
        libusbhid.so.3 => /usr/lib/libusbhid.so.3 (0x105fd000)
        libX11.so.6 => /usr/local/lib/libX11.so.6 (0x10601000)
        libXau.so.6 => /usr/local/lib/libXau.so.6 (0x106ed000)
        libXdmcp.so.6 => /usr/local/lib/libXdmcp.so.6 (0x106f0000)
        librpcsvc.so.4 => /usr/lib/librpcsvc.so.4 (0x106f5000)
>
>  Here is another experimental update that forces -lthr on 6.x, and
> also updates to qemu svn r5313:
>        http://people.freebsd.org/~nox/qemu/qemu-devel-20080924.patch

I just built this update and it seems to have fixed the issue.  Host
CPU usage again tracks with guest CPU usage and all seems well.  I'll
continue to use this build to see if anything else crops up.

Please let me know if there is anything other information I can provide.

Thanks again,
Matt
>
> >Thank you for the continued work on this port!
>
>  You're welcome! :)
>        Juergen