Re: [User-mode-linux-user] 2.3.48_devfs

[William S. <wst...@po...>]

On Wed, 1 Mar 2000, Jeff Dike wrote:

> > it's perfect for my hardware.
> 
> Blazing fast processors and tons of everything :-) ?

	*smile*  P90, 40M maxed out laptop, and tons 'o nothing!

> > 	- 2.3.48_devfs-uml is more stable than 2.3.46-uml; the latter crashed
> > within a few minutes and sometimes before it finished booting.
> > 2.3.48_devfs stays up longer.
> 
> I don't remember fixing any bugs like that between .46 and .48.  Maybe bugs 
> were fixed in the rest of the kernel.  One thing that will help stability when 

	Very likely.

> I put the packages out is that virtual consoles are turned off.  My forking 
> and execing of xterm is causing memory corruption.  I have a fix in mind, and 
> that will be added pretty quickly.

	Awwww, and I _liked_ the xterms.  That's a really cool feature.  
Could they at least be an option?

> > 	- For those without a devfs capable root_fs, the quick and easy
> > workaround is to add devfs=nomount to the command line, ala ./linux
> > devfs=nomount 
> 
> So you're one of the ones that grabbed the devfs kernel.  My release notes 
> said not to do that :-)  I put it out for completeness, and for the masochists 
> out there.

	*hand raised*  Me, Teach, me!  I'm a software masochist!
	I'm playing for the moment, and the only precompiled one you had
was w/ devfs.  Luckily, the "devfs=nomount" basically returns the kernel
to it's normal behavior for backwards compatibility.
	I'll mail you my devfsd rpm I just finished preparing under
separate cover; it's available on request for anyone else.

> > 	- I'm sure it doesn't surprise you that I'm getting occasional errors
> > on the uml console.  The latest (on 2.3.48_devfs w/ debian root_fs):
> > Unimplemented syscall : 163
> >                            Untested (16019) [0x10154c68]:
> > syscall_kern.c line 662 
> 
> Something did a mremap.  Not all of the system calls are hooked up yet.  If 
> you see that again, attach gdb to the tracing thread, and look at 
> current_task.comm, and tell me what the command line was for it.  I like to 

	And here's where I get to publicly admit that I'm a complete
novice at debugging.  I don't know how to use gdb.  Oh well, dive in and
learn:

[root@sparrow uml]# gdb linux-2.3.48_devfs 18245
[snip]
Attaching to program: /home/wstearns/uml/linux-2.3.48_devfs, Pid 18245
0x10085529 in __wait4 ()
(gdb) c
Continuing.

... run "cd /", then "ls -alR" on an xterm... crash with
Unimplemented syscall : 163
                           Untested (18468) [0x10154c68]: syscall_kern.c line 662
on the console... press Ctrl-C on gdb:

Program received signal SIGINT, Interrupt.
0x10085529 in __wait4 ()
(gdb) print current_task.comm
$1 = "ls\000h\000\000r\000\000\000\000\000\000\000\000"

	Any closer?
	Just for reference, this is 2.3.48_devfs with the debian root_fs
from SourceForge.

> > I'll try putting together my own root_fs at some point, but need a
> > working loop device in my host kernel first; 2.3.48-i386 doesn't quite
> > seem to have it yet.
> 
> Where do you get your kernels from?  My RH kernels have always had the loop 
> device.

	My apologies.  The kernel itself _has_ the loop device, but I'm
spending time in the 2.3.4x kernels (see "software masochist",
above).  The loop mount is _there_ but seems unstable at this time.
	Thanks again for all your work.
	Cheers,
	- Bill

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	"As a computer I find your faith in technology amusing."
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William Stearns (wst...@po...).  Mason, Buildkernel, named2hosts, 
and ipfwadm2ipchains are at: http://www.pobox.com/~wstearns/
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