Re: devfs breakage in 2.4.0 release

[Andris Pavenis]

On Friday 12 January 2001 13:35, Andris Pavenis wrote:
> On Saturday 06 January 2001 15:28, Andris Pavenis wrote:
> > Noticed following devfs related problems with kernel version 2.4.0 on one
> > Pentium 200MMX box (the same problem with 2.4.0-ac2, but earlier
> > 2.4.0-test10 doesn't have this problem)
> >
> > I was able to reproduce it reliably by following steps:
> >          - booted machine in runlevel 3
> >          - logged in as user and started MC (on first console)
> >          - logged out
> >          - logged in as different user (in this case root) and tried to
> > start MC again
> >
> > This time it hangs. The source of problem appears to be devfs related as
> > devfsd exited with error message that it cannot state vcc/1 as there is
> > no such file or directory. Related parts of log files (boot parameter
> > devfs=dall) and other related information (I hope...) is in attachment.
> > Of course MC is not behaving nicely, but the primary source of problem
> > seems to be devfs
>
> As I tested devfsd dies after I'm logging out (very often on P200MMX,
> much more seldom on P3 700). I suspect some devfs related race
>
> > On this machine kernel was compiled for Pentium CPUs. I tried to
> > reproduce the same on a different machine with Pentium III 700 using
> > kernel 2.4.0. It took more relogging as on Pentium 200, but I got the
> > same problem once (on slower machine I was able to reproduce it more
> > reliably).
>
> I tries 2.4.1-pre3 and got the same. Modifying devfsd.c to retry stating
> some times before giving up workarounds the problem (As far as I tested
> I'm getting only one retry ...)
>
> Perhaps it's kernel's bug anyway, but I think it's doesn't harm to make
> devfsd slightly more errorproof. I'm including patch for devfsd (I had also
> to define __USE_GNU to get devfsd compile with glibc-2.2 at all ...)
>
> Of course best solution would be to fix the race itself (it appeared
> sometimes between 2.4.0-test10 and 2.4.0-test12, first one is OK) ....
>

I spent some time building various kernels on P200MMX box I have this problem
to happen more often. It looks that problem appears in 2.4.0-test12-pre8
but is not present in 2.4.0-test12-pre7

Andris