Subject: Linux-Development Digest #899
From: Digestifier <Linux-Development-Request@senator-bedfellow.MIT.EDU>
To: Linux-Development@senator-bedfellow.MIT.EDU
Reply-To: Linux-Development@senator-bedfellow.MIT.EDU
Date:     Fri, 8 Jul 94 15:13:13 EDT

Linux-Development Digest #899, Volume #1          Fri, 8 Jul 94 15:13:13 EDT

Contents:
  Re: Fatal Signal 11 - reproduceable ! (Rob Janssen)
  Re: TCP/IP networking for DOSEMU (Rob Janssen)
  Re: tcsh bug: more information (Drew Eckhardt)
  Re: dual mon support in 1.0.9? (todd j. derr)
  Re: TCP/IP networking for DOSEMU - Why it should be there. (James B. MacLean)
  Re: Help: Modules in Linux kernel (Alan Cox)
  Howto make shared lib (Andrej Gabara)
  Re: Help: Modules in Linux kernel (Mitchum DSouza)
  Re: dual mon support in 1.0.9? (Luke Howard)
  Re: dual mon support in 1.0.9? (Luke Howard)
  Re: Howto make shared lib (Naresh Sharma)
  Re: Linux seems to perform terribly for large directories (Chris Bitmead)
  Re: Mosaic World Icon gone crazy (Chris Bitmead)
  Re: to the kernel patch writers (Rainer Zimmermann)
  mmap() bug in 1.1.23 (Rainer Zimmermann)
  description of linux syscalls? (Rainer Zimmermann)
  Re: Where are kernel versions kept? (Yasuo Ohgaki)

----------------------------------------------------------------------------

From: rob@pe1chl.ampr.org (Rob Janssen)
Subject: Re: Fatal Signal 11 - reproduceable !
Reply-To: pe1chl@rabo.nl
Date: Fri, 8 Jul 1994 07:14:27 GMT

In <1994Jul7.193105.20509@kbbs.kiel.sub.org> hp@kbbs.kiel.sub.org (Holger Petersen) writes:


>The following small C-program gives the Message "Fatal signal 11"
>on _four_ different PC's with 3 different versions of Linux 
>_AND_ 
>on _one_ PC with "Interaktive Unix", but only with Gnu-C. 

>I found it in a 4-lines .sig; I think it comes from the "obfuscated C"-
>contest. I edited it slightly :-) to get it into 72 chars/line...

[...]

>as well as substituting "Dollar" or "DM" or "Yen" for "$" :-)


>Happy Bug-Hunting,  Holger  (dg3lp)

1. $ is not a valid variable name in standard C.
   maybe it is on some dialects on systems that use $ in names (VMS)

2. This sounds more like a bug in GNU C, so you better ask it in a related
   newgroup.  Be prepared, however, to be flamed about sending a bug report
   without even mentioning the version number of the compiler...

Rob
-- 
=========================================================================
| Rob Janssen                | AMPRnet:   rob@pe1chl.ampr.org           |
| e-mail: pe1chl@rabo.nl     | AX.25 BBS: PE1CHL@PI8UTR.#UTR.NLD.EU     |
=========================================================================

------------------------------

From: rob@pe1chl.ampr.org (Rob Janssen)
Subject: Re: TCP/IP networking for DOSEMU
Reply-To: pe1chl@rabo.nl
Date: Fri, 8 Jul 1994 07:19:41 GMT

In <rick.112.773619238@sjsumcs.sjsu.edu> rick@sjsumcs.sjsu.edu (Richard M. Warner) writes:

>The correct answer is that the higher level manager (ODI in Netware's
>case, NDIS for others) has the ability to manage multiple sessions/
>protocols/framings on a single card.  I am not sure about the internals of 
>NDIS, but the ODI drivers make the single board look like multiple 
>virtual boards. The functionality missing in Linux is this higher level 
>network manager - someone creates one for Linux and then the NIC will be 
>able to handle multiple concurrent network sessions over one, or many, 
>protocol stacks.

Fortunately, that is also incorrect :-)

This functionality *is* available in the Linux kernel.  It is in fact what
the dosemu packet driver uses to get access to the card that Linux also
uses for its networking.  In fact, you can even get access for the same
protocols as Linux uses and each gets a copy of all received packets.

The trouble is that Linux networking will be making responses to some of
the packets that are really destined for the dosemu box, because the TCP/IP
protocol specifications tell it to.  This is mostly solved by running a
different IP address in the dosemu box than the Linux networking uses, but
subtle problems remain.  (e.g. forwarding has to be turned off in both
the Linux networking and the software running in the dosemu box)

Rob
-- 
=========================================================================
| Rob Janssen                | AMPRnet:   rob@pe1chl.ampr.org           |
| e-mail: pe1chl@rabo.nl     | AX.25 BBS: PE1CHL@PI8UTR.#UTR.NLD.EU     |
=========================================================================

------------------------------

From: drew@kinglear.cs.colorado.edu (Drew Eckhardt)
Subject: Re: tcsh bug: more information
Date: 7 Jul 1994 03:47:46 GMT

In article <DHOLLAND.94Jul6184724@husc7.harvard.edu>,
David Holland <dholland@husc7.harvard.edu> wrote:

Did you leave yourself logged in, is this flame bait, or are you
really as ignorant as your post would imply?

>
>vassili@cs.sunysb.edu's message of 6 Jul 1994 17:06:00 GMT said:
>
> > These days - there is absolutely no reason to use anything but Perl
> > for anything you might want to write in shell. On the other hand there is
> > no reason to use anything but Perl to write something that you
> > might want to write in C (except Kernel code :-)
> > ( yeah - you have .login .cshrc .profile and whatever to mess things up..)
>

>On the contrary, there is absolutely no reason to use Perl for
>anything whatsoever. 

>It has all the drawbacks of both C and shell
>scripts, and none of the advantages of either. 

Advantages common with shell programming : rapid prototyping, relatively 
        seamless integration of external programs, relaxed type 
        restrictions, etc.

Advantages common with 'C' programming : access to standard UNIX system
        calls, data structures with PERL5, availability of 
        debugging facilities, etc.

>A perl script is as >slow, or slower, than a shell script, 

Usually, I don't bother to implement scripts in both 
PERL and /bin/sh since PERL is usually faster, but the last
Bourne shell script (specifically, the Configure script from the 
Linux source ) I rewrote in Perl ran over an order of magnitude
faster, with run time dropping from 30 seconds to 2 on the 386-33
I used at the time.

In other cases, the improvement gained may be less, although the
separate compilation and execution of PERL scripts tend to make them
faster than scripts written in purely interpreted shells.

>and it's as hard to deal with
>and write in as C. Maybe more so. 

There are certain things that PERL does well, ie text manipulations
which would be significantly more complicated and difficult to implement
in 'C', just as there are certain things which can be implemented 
more cleanly in 'C'.

If you were ignorant enough to use the wrong tool for a job, leaving
yourself with an impression like this, you got what you deserved.

-- 
Drew Eckhardt drew@Colorado.EDU
1970 Landcruiser FJ40 w/350 Chevy power
1982 Yamaha XV920J Virago

------------------------------

From: infidel+@pitt.edu (todd j. derr)
Subject: Re: dual mon support in 1.0.9?
Date: 8 Jul 1994 07:48:43 GMT

In article <2vi60k$7v@zola.apana.org.au>,
Luke Howard <lukeh@zola.apana.org.au> wrote:

>OK, well I installed the patches for kernel 1.0(.9) (I'm still interested if 
>anyone has some for 1.1.x). 

hrm.  I had worked on the dual-mon patches way back when....  Jeff
Grills ended up taking them over from whomever was doing them before,
and my mono monitor blew up, so I haven't touched them in a while.

however, Jeff no longer runs Linux, and I can get a mono monitor cheap,
so... I'll get in touch with Jeff, work the patches into 1.1.x, and
become the active maintainer of them.  Sound good to everyone?

todd.

------------------------------

From: jmaclean@fox.nstn.ns.ca (James B. MacLean)
Subject: Re: TCP/IP networking for DOSEMU - Why it should be there.
Date: 8 Jul 1994 09:20:10 -0300

In article <1994Jul6.004325.9705@titan.westfalen.de> johannes@titan.westfalen.de (Johannes Stille) writes:
>From: johannes@titan.westfalen.de (Johannes Stille)
>Subject: Re: TCP/IP networking for DOSEMU
>Date: Wed, 6 Jul 1994 00:43:25 GMT

>I think that there is hardly any need for a TCP/IP connection to DOSEMU.
>Usually you can get TCP/IP software for Linux that is both cheaper and
>better.
>If I'm wrong, please tell me so. If there is suffcient need, I'd
>probably write the drivers.

  If I may interject here :-). I imagine the same could be said about much 
of the software that DOSEMU is being used for. From my point of view, I've 
always wanted to see DOSEMU become as compatible with DOS programs as 
possible. For me, this will mean running Mosaic for Windows, Minuete, SOSS, 
and anything else that current DOS users would appreciate not HAVING to give 
up to enjoy all the benefits of Linux. I get a good percentage of E-mail 
that usually ends with something to the effect of 'Now if I could only run 
program XYZ, I'd never have to boot MS-DOZE again'. This drives me, as I 
believe it drives quite a few on the DOSEMU development team, to add all 
the functionality that they can :-).
  Again, personally, I've already used DOSEMU to test XFS/NFS packages for 
DOS over the pty's... because I can, and I have no need to set up an extra 
box. I've also been able to trace down many DOS buglets, just by being able 
to run them on DOSEMU. So as another case, it's a great plus to have this 
support for the development crew.
  I know I've been doing a poor job of tantalizing anyone into taking 
anything on with this :-(, but Johannes, I'd really appreciate the 
interface, even just to say that YES DOSEMU supports TCP/IP over the 
pktdrvr. Jason, Rob and Tim Bird have blown the useablity of DOSEMU wide 
open with an interface to NetWare. Now I'm interested in getting full-true 
pktdriver compatibility.

>        Johannes

Later,
JES
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
James B. MacLean                    jmaclean@fox.nstn.ns.ca
Department of Education
Nova Scotia, Canada (902) 424-8438

------------------------------

From: iialan@iifeak (Alan Cox)
Subject: Re: Help: Modules in Linux kernel
Date: Fri, 8 Jul 1994 11:50:28 GMT

In article <2vhd79$6s1@smurf.noris.de> urlichs@smurf.noris.de (Matthias Urlichs) writes:
>Fixed major numbers aren't necessary any more anyway, except for the
>disk you're booting from, and the console.

The prospect of a file system coming up read only and MAKEDEV not being able
to run to number your devices properly so fsck can recover disks to say
the least worries me. There is a lot of scope for getting variable numbering
wrong. 

Alan

-- 
Alan Cox: gw4pts@gw4pts.ampr.org      \\  //          GW4PTS@GB7SWN
=======================================\\//===================================
<<<<<<     Toolkits are for WIMPS :::: //\\Lib :::: the only way to fly >>>>>>
======================================//==\\==================================

------------------------------

From: gabara@Informatik.Uni-Tuebingen.DE (Andrej Gabara)
Subject: Howto make shared lib
Date: 8 Jul 1994 01:46:22 GMT
Reply-To: gabara@peanuts.Informatik.Uni-Tuebingen.DE

Sorry if this is not the appropriate newsgroup. How do I create a shared
library, such as libDuh.sa for linux? 

Thank's for all hints,

-Andrej



------------------------------

From: Mitchum DSouza <m.dsouza@mrc-apu.cam.ac.uk>
Subject: Re: Help: Modules in Linux kernel
Date: 8 Jul 1994 11:52:16 -0400
Reply-To: m.dsouza@mrc-apu.cam.ac.uk

Matthias Urlichs writes:
| In comp.os.linux.development, article <2v8ovo$n1v@senator-bedfellow.mit.edu>,
|   m.dsouza@mrc-apu.cam.ac.uk writes:
|
| > or with the newer kernel (1.1.23 and above) modules code
| >       nic.funet.fi /incoming/lo.3.3.tar.gz
| > 
| Good idea except that /pub/OS/Linux/incoming is not readable.

Unfortunately my mind was on vacation. I meant

        tsx-11.mit.edu:/pub/linux/BETA/loop/lo.3.3.tar.gz

| In fact, I assume you mean tsx-11.mit.edu, nit ftp.funet.fi, which _does_
| have an /incoming (unreadable, and the file has already been moved to
| /pub/linux/BETA/loop, but still...)

Not actually the file is readable (if you know the name), but cannot be
stat()'ed - i.e. no "x" flag on the directory. You can still get the file if
you know the name.

| > Version 3.3 also shows the ability to change MAJOR device numbers dynamically
| > as the loop device is not oficially registered.
| > 
| Fixed major numbers aren't necessary any more anyway, except for the
| disk you're booting from, and the console.

They are if some other device decides 28 (for example) is good major, or Linus
allocates it to someone else. The presetting of exported symbols make a
convinent means of changing major numbers eaisly. I could parse /proc/devices
and allocate an unused major for the loop however.

Mitch

------------------------------

From: lukeh@zola.apana.org.au (Luke Howard)
Subject: Re: dual mon support in 1.0.9?
Date: 8 Jul 1994 10:18:28 +1000

Luke Howard (lukeh@zola.apana.org.au) wrote:

: If the patches won't work, does anyone know whether it's possible to 
: modify them, or to at least get some support for a secondary (monochrome) 
: display adaptor with the >1.0 kernels?

OK, well I installed the patches for kernel 1.0(.9) (I'm still interested if 
anyone has some for 1.1.x). 

One thing though - and I assume this is related for it's the first time 
it has happened - I'm getting the following message in my messages file. 
Is it something I can safely ignore?

zola kernel: gfp called nonatomically from interupt 00119556

and on one occasion, from interrupt 001192db.


TIA,

luke
-- 

                      Luke Howard, Luke.Howard@apana.org.au
                   URL http://zola.apana.org.au/0/zola/people
                                Utilisez Linux!!!

------------------------------

From: lukeh@zola.apana.org.au (Luke Howard)
Subject: Re: dual mon support in 1.0.9?
Date: 8 Jul 1994 10:22:28 +1000

Luke Howard (lukeh@zola.apana.org.au) wrote:
: Luke Howard (lukeh@zola.apana.org.au) wrote:

: zola kernel: gfp called nonatomically from interupt 00119556

zSystem.map says that it's in between _do_no_page and _do_page_fault. 
(including the interrupt mentioned in the last post)



-- 

                      Luke Howard, Luke.Howard@apana.org.au
                   URL http://zola.apana.org.au/0/zola/people
                                Utilisez Linux!!!

------------------------------

From: nash@dutllu4.gmd.de (Naresh Sharma)
Subject: Re: Howto make shared lib
Reply-To: Naresh.Sharma@LR.TUDelft.NL
Date: Fri, 8 Jul 1994 07:31:49 GMT

Andrej Gabara (gabara@Informatik.Uni-Tuebingen.DE) wrote:
: Sorry if this is not the appropriate newsgroup. How do I create a shared
: library, such as libDuh.sa for linux? 

: Thank's for all hints,

: -Andrej

You need the package tools-2.15.tar.gz from sunsite. It contains all you
need to have to build shared libs. libSharedDuh.so etc.

Have fun.

Naresh

--
_______________________________________________________________________________
Naresh Sharma [N.Sharma@LR.TUDelft.NL]  Herenpad 28            __|__
Faculty of Aerospace Engineering        2628 AG Delft   \_______(_)_______/
T U Delft               Optimists designed the aeroplane,     !  !  !  
Ph(Work) (+31)15-783992 pessimists designed the parachute!
Ph(Home) (+31)15-569636 Plan:Design Airplanes on Linux the best OS on Earth!
==============================PGP=KEY=AVAILABLE================================

------------------------------

From: chrisb@cssc-syd.tansu.com.au (Chris Bitmead)
Subject: Re: Linux seems to perform terribly for large directories
Date: 7 Jul 1994 13:54:18 +1000

herbert@greathan.apana.org.au (Herbert Xu) writes:

>Here are some facts on a lightly loaded 386SX-20 with 5Mb RAM:

>$ ls -l test
>total 61
>drwx------   2 herbert  greathan    60416 Jul  6 17:05 dir1
>drwx------   2 herbert  greathan     1024 Jul  6 17:07 dir2

>dir1 contains 5000 files, their names are 0, 1, ..., 4999
>dir2 contains 1 file called 0
>All files are created by '> file'

>$ time ls -f1 dir1 > /dev/null
>real   0:05.94
>user   1.13
>sys    2.69

>$ time ls -f1 dir2 > /dev/null
>real   0:00.53
>user   0.01
>sys    0.23

>$ time ls -l dir1/0 > /dev/null
>real   0:00.66
>user   0.05
>sys    0.27

>$ time ls -l dir2/0 > /dev/null
>real   0:00.42
>user   0.04
>sys    0.29

These tests don't prove much, assuming you created the files in numerical
order. dir1/0 will  be the first entry and no searching will be done. How
about trying "time ls -l dir1/4999"

------------------------------

From: chrisb@cssc-syd.tansu.com.au (Chris Bitmead)
Subject: Re: Mosaic World Icon gone crazy
Date: 7 Jul 1994 13:56:57 +1000

staferne@risc.uni-linz.ac.at (Stefan Taferner) writes:

>I had these problems too. I took the source of Mosaic and removed the
>function that pastes the world picture into the window. But don't ask
>me which file it was. It was something similar to pixmap, picture, ...
>or so.

I heard it was because select system call returns the time left. (Bsd
never got round to implementing it, so many programs make wrong
assumptions). Try saving the time value before passing it to select() and
restoring it afterwards. I think this is fixed in a later version.


------------------------------

From: zimmerm@Informatik.Uni-Marburg.de (Rainer Zimmermann)
Subject: Re: to the kernel patch writers
Date: 8 Jul 1994 15:01:21 GMT

Thomas Graichen (graichen@sirius.physik.fu-berlin.de) wrote:
: - is'nt it possible to include an patch of ChangeLog into every new (1.1.x)
: patch - it is a bit frustrating to "read" about 300k patch-file to find out
: what has changed since the last patch (some weeks ago somebody wrote some-
I can only agree very much :-)

: - is it ok that i see in a kernel without tcp/ip networking support the
: "Swansea ... NET 3.016" or so at boot-time (i think there are some forgotten
: #ifdef CONFIG_NET)
Probably it's ok. Actually, I thought of the same thing and grepped it in
the kernel source-- the code that produces it has something to do with
sockets, wich are there even w/o net support (X needs them, for instance).
Though I still don't like it very much ;)

--rainer





:         thomas graichen, freie universitaet berlin, fachbereich physik

:                  email: graichen@sirius.physik.fu-berlin.de

:  ------------------------------------------------------------------------------



------------------------------

From: zimmerm@Informatik.Uni-Marburg.de (Rainer Zimmermann)
Subject: mmap() bug in 1.1.23
Date: 8 Jul 1994 13:11:21 GMT


I played a little with mmap()-ing on on regular files and it seems 
to have a bug (kernel 1.1.23):  
If you try to map a 'busy' (i.e. currently running) executable file
with the MAP_FIXED flag set, the mmap() call returns no error (as it 
probably should for readonly access), but the mapped pages contain 
complete garbage. Without MAP_FIXED it works fine, and MAP_SHARED/
MAP_PRIVATE doesn't matter.

The mapped data seems to be the same for the same file and different
for different files, but has nothing to do with the actual contents
of the file.
could someone with more understanding of kernel internals have a look ? :)

Question: What does MAP_FILE (defined as 0 in <sys/mman.h>) do? nothing? 
If I pass it as the 'flags' parameter alone, I just get an error.

Also, I realized that mmap() is not supported on msdos filesystems,
the mmap entry in the msdos_file_operations struct (fs/msdos/file.c)
says NULL rather than generic_mmap. Is there some reason for this that 
I'm missing?

--rainer





------------------------------

From: zimmerm@Informatik.Uni-Marburg.de (Rainer Zimmermann)
Subject: description of linux syscalls?
Date: 8 Jul 1994 13:15:48 GMT

hi lx'ers,

i wonder whether there is another way but guessing to get information
about what all the nice linux system calls do, what their special flags
mean, what can expected to work and what not :), etc...

Is there any sort-of-documentation lying around on the net?

please email or post in this newsgroup.

thanx in advance,
--rainer



------------------------------

From: yasuo@via.term.none (Yasuo Ohgaki)
Subject: Re: Where are kernel versions kept?
Date: Wed, 6 Jul 1994 22:26:38 GMT

Pete Kruckenberg (kruckenb@sal.cs.utah.edu) wrote:
: Quick question: is there anyplace where I can pick up specific
: versions of the Linux kernel source without having to apply each patch
: level (for example, I could ftp version 1.1.14, rather than getting
: 1.1.0 and applying patches 1-14)?

: Thanks.
: Pete.

:   ------------------------------------------------------------------------
:   Pete Kruckenberg                       School: kruckenb@sal.cs.utah.edu
:   University of Utah                       Work: pete@dswi.com
:   Computer Engineering    For even more addresses, "finger pete@dswi.com"

linuxftp.caltech.edu:/pub/Linux/pached-kernels

--
Yasuo Ohgaki
e-mail: yohgaki@diana.cair.du.edu


------------------------------


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