[Qemu-devel] Math/FP problems in 0.5.0?

[Qemu-devel] Math/FP problems in 0.5.0?

[Leigh Dyer]

Hi,

I've been playing with both CVS and the 0.5.0 release of qemu today,
using a debian system that I installed under bochs. The system boots and
seems to run quite well, but I noticed some numerical problems showing
up - e2fsck's percentage meter switched between 0.0% and nan%, and
running nbench produced similar results, with either 0 or nan for all
reported values in the output.

I thought that it might be a problem with my toolchain (gcc 3.3 in
Debian unstable messes things up, so I use unstable's gcc 3.2), so I
grabbed the qemu binary and linux test image from the website. Running
df seems to show the problem as well: the Capacity of the filesystem is
shown as 0%, and if you use df -h, Size, Used and Avail all show as 0G.

Apart from that, I have to say that 0.5.0 is very impressive - keep up
the good work :)

Thanks
Leigh

Re: [Qemu-devel] Math/FP problems in 0.5.0?

[Fabrice Bellard]

Leigh Dyer wrote:
> Hi,
> 
> I've been playing with both CVS and the 0.5.0 release of qemu today,
> using a debian system that I installed under bochs. The system boots and
> seems to run quite well, but I noticed some numerical problems showing
> up - e2fsck's percentage meter switched between 0.0% and nan%, and
> running nbench produced similar results, with either 0 or nan for all
> reported values in the output.
> 
> I thought that it might be a problem with my toolchain (gcc 3.3 in
> Debian unstable messes things up, so I use unstable's gcc 3.2), so I
> grabbed the qemu binary and linux test image from the website. Running
> df seems to show the problem as well: the Capacity of the filesystem is
> shown as 0%, and if you use df -h, Size, Used and Avail all show as 0G.

I am going to try to reproduce the problem. Maybe the memory macros for 
floating point access are incorrect.

Fabrice.

Re: [Qemu-devel] Math/FP problems in 0.5.0?

[Fabrice Bellard]

My last commits should fix the issue.

Fabrice.

Leigh Dyer wrote:
> Hi,
> 
> I've been playing with both CVS and the 0.5.0 release of qemu today,
> using a debian system that I installed under bochs. The system boots and
> seems to run quite well, but I noticed some numerical problems showing
> up - e2fsck's percentage meter switched between 0.0% and nan%, and
> running nbench produced similar results, with either 0 or nan for all
> reported values in the output.
> 
> I thought that it might be a problem with my toolchain (gcc 3.3 in
> Debian unstable messes things up, so I use unstable's gcc 3.2), so I
> grabbed the qemu binary and linux test image from the website. Running
> df seems to show the problem as well: the Capacity of the filesystem is
> shown as 0%, and if you use df -h, Size, Used and Avail all show as 0G.
> 
> Apart from that, I have to say that 0.5.0 is very impressive - keep up
> the good work :)
> 
> Thanks
> Leigh

Re: [Qemu-devel] Math/FP problems in 0.5.0?

[Leigh Dyer]

On Wed, 2003-10-29 at 10:12, Fabrice Bellard wrote:
> My last commits should fix the issue.
> 

I've just tested current CVS, and the fix works like a charm.

Thanks
Leigh

> Fabrice.
> 
> Leigh Dyer wrote:
> > Hi,
> > 
> > I've been playing with both CVS and the 0.5.0 release of qemu today,
> > using a debian system that I installed under bochs. The system boots and
> > seems to run quite well, but I noticed some numerical problems showing
> > up - e2fsck's percentage meter switched between 0.0% and nan%, and
> > running nbench produced similar results, with either 0 or nan for all
> > reported values in the output.
> > 
> > I thought that it might be a problem with my toolchain (gcc 3.3 in
> > Debian unstable messes things up, so I use unstable's gcc 3.2), so I
> > grabbed the qemu binary and linux test image from the website. Running
> > df seems to show the problem as well: the Capacity of the filesystem is
> > shown as 0%, and if you use df -h, Size, Used and Avail all show as 0G.
> > 
> > Apart from that, I have to say that 0.5.0 is very impressive - keep up
> > the good work :)
> > 
> > Thanks
> > Leigh
> 
> 
> 
> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://mail.nongnu.org/mailman/listinfo/qemu-devel
> 

Re: [Qemu-devel] Math/FP problems in 0.5.0?

[Stefano Marinelli]

On Tue, Oct 28, 2003 at 04:46:40PM +1100, Leigh Dyer wrote:
> up - e2fsck's percentage meter switched between 0.0% and nan%, and
> running nbench produced similar results, with either 0 or nan for all
> reported values in the output.

...and, sometimes, it hangs in a "segmentation fault", during the
fsck (but also in other situations).

Stefano