Linux-Development-Sys Digest #863, Volume #7 Tue, 16 May 00 18:13:20 EDT
Contents:
BIOS Int 15-E820, memory holes, and high_memory (Timur Tabi)
G++ (egcs) problems with pow() under optimisation (Jeffrey Ng)
Re: Weird behavior of dual-boot Tyan S1854 (Jerry Natowitz)
Re: G++ (egcs) problems with pow() under optimisation (Paul Kimoto)
Re: What's with PCMCIA and pre[68]? (Paul Kimoto)
Webmin (Mongoose)
Re: Can't boot 2.3.99pre8 on Pentium (Christian Winter)
Re: Apply the dvd-cd Patch. (Matt Lesko)
Re: Webmin (H.Bruijn)
Finding the status of a process (Doug Schulz)
Re: Windows98 IDE driver screwed up Linux UDMA disk access? (Stefaan A Eeckels)
Re: ANSI C & void main() (David Wragg)
----------------------------------------------------------------------------
From: Timur Tabi <[EMAIL PROTECTED]>
Subject: BIOS Int 15-E820, memory holes, and high_memory
Date: Tue, 16 May 2000 20:09:53 GMT
The new setup.S in the 2.3 kernel uses the E820 function of INT 15 to
obtain a memory map. This memory map not only tells you how much
memory is in the system, but it also tells you where the ACPI tables
are and whether there are any memory holes.
My knowledge of the Linux kernel is limited, and I don't have any
hardware that appears to have "memory holes" in it, so I need someone
to answer this question for me.
If a system has 16MB (for example), and it reports a 64KB memory hole,
does the 64KB count as part of the 16MB? In other words, without the
hole, the highest physical memory location is 0xFFFFFF (16M - 1). With
the hole, is the highest address still 0xFFFFFF or is it now 0x100FFFF
(16M - 1 + 64K)? I guess my questions is, what exactly is a "memory
hole"? Is it just reserved memory, or does it physically not exist?
--
Timur Tabi
Interactive Silicon - http://www.interactivesi.com
Remove "nospam_" from my email address when replying
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
From: Jeffrey Ng <[EMAIL PROTECTED]>
Subject: G++ (egcs) problems with pow() under optimisation
Date: Tue, 16 May 2000 21:25:00 +0100
Has anyone had any problems when they enable compiler optimisations for
programs using the pow() math function call?
I have a huge scientific program that uses a lot of power calls in lots
of places and used to wonder why it would seg fault when I enabled
optimisations. Just recently, I have narrowed it down to the culprit.
The following little piece of code can trigger the fault on two
different machines that I've tried (Pentium II and K7 Athlon).
Compil is standard: g++ -O -o powtest powtest.cc
I've got egcs-2.90.29 980515.
Can anybody reproduce the error on their g++ compilers?
Cheers,
Jeffrey Ng.
============
#include <math.h>
#include <stdio.h>
void main(int argc, char **argv){
char modelFileName[254], classFileName[254], saveFileName[254];
printf("%f\n", pow(1.2,2.5)); fflush(stdout);
}
------------------------------
Crossposted-To: alt.comp.periphs.mainboard.tyan
Subject: Re: Weird behavior of dual-boot Tyan S1854
Reply-To: [EMAIL PROTECTED]
From: [EMAIL PROTECTED] (Jerry Natowitz)
Date: Tue, 16 May 2000 20:38:49 GMT
In article <[EMAIL PROTECTED]>,
<[EMAIL PROTECTED]> wrote:
>In comp.os.linux.development.system Jerry Natowitz <[EMAIL PROTECTED]> wrote:
>| In article <[EMAIL PROTECTED]>,
>| <[EMAIL PROTECTED]> wrote:
>|>In comp.os.linux.development.system Jerry Natowitz <[EMAIL PROTECTED]> wrote:
>|>
>|>| I just diagnosed a really strange behavior I found on my dual (Linux and
>|>| Win98SE) boot Tyan S1854. I found that if I booted Linux first and then
>|>| tried to boot Windoze, the syetem just sat there doing nothing. Hitting the
>|>| reset didn't change thing, the system still hung right after the message
>|>| about verifying the configuration. A power-cycle would fix things.
>|>|
>|>| After some investigation I found out that my use of modules in Linux for
>|>| the CD-ROMs and Zip drive were the cause. Change:
>|>| CONFIG_BLK_DEV_IDECD=m
>|>| CONFIG_BLK_DEV_IDEFLOPPY=m
>|>| to
>|>| CONFIG_BLK_DEV_IDECD=y
>|>| CONFIG_BLK_DEV_IDEFLOPPY=y
>|>| and all is well. Kernel versions, BTW, are both 2.2.15 and 2.3.99pre9-1
>|>
>|>In the case where you had modules, did the hang result when you actually did
>|>load the modules, or when you actually did not load them? Did you try it
>|>both ways? If it fails both ways vs. fails only if loaded or only if not
>|>loaded, that could mean something (although I don't know what that would be).
>|
>| I just tried and found that the hang only occurs when the modules are not
>| loaded. As you say, not sure what that means ...
>
>I'll guess and suggest that the base kernel probing still touches those
>devices, but does so incompletely, leaving them or related devices in a
>state that they are looking for something special to happen, and when
>Windows comes along accesses them, it gets an error, but doesn't try to
>clear the device. Sadly, most devices do NOT really reset when a system
>reset is performed during a soft boot. The reset button may not be doing
>any better than that. The BIOS should attempt to clear devices it knows
>about, but if you have them disabled in BIOS (if you load them as modules
>perhaps your BIOS is set to ignore them as well). But even if they are
>known, the BIOS may not (I've seen nearly as many fault BIOS designs as I
>have seem computer models).
>
>Are you so tight on RAM that you need to have these as modules?
No, I have plenty of RAM. This started with a couple of needs for modules:
1) The emu10k1 driver, which now works fine when non-modular.
2) The scsi-emulation driver for IDE CD-Rs.
I got carried away and turned almost everything into a module.
--
Jerry Natowitz - jin at spdcc dot com
------------------------------
From: [EMAIL PROTECTED] (Paul Kimoto)
Subject: Re: G++ (egcs) problems with pow() under optimisation
Date: 16 May 2000 16:44:20 -0500
Reply-To: [EMAIL PROTECTED]
In article <[EMAIL PROTECTED]>, Jeffrey Ng wrote:
This is off-topic for c.o.l.d.system, but anyway ...
> Has anyone had any problems when they enable compiler optimisations for
> programs using the pow() math function call?
> Compil is standard: g++ -O -o powtest powtest.cc
> I've got egcs-2.90.29 980515.
That's one of the egcs-1.0.* versions, and this is probably
a manifestation of a known problem. See the glibc FAQ at
<http://sourceware.cygnus.com/glibc/glibc-faq.html>
and look at item 3.14 (~M_PI!).
--
Paul Kimoto <[EMAIL PROTECTED]>
------------------------------
From: [EMAIL PROTECTED] (Paul Kimoto)
Subject: Re: What's with PCMCIA and pre[68]?
Date: 16 May 2000 16:48:47 -0500
Reply-To: [EMAIL PROTECTED]
In article <8fpdb9$lmc$[EMAIL PROTECTED]>, bill davidsen wrote:
> Is this believed to work? Is there a later version of the utilities?
> I've made it work in 2.2.14 and 2.3.48, so the process seems to have
> changed if it is in fact operational.
>
> Pulled the latest copy of the pcmcia package May 14th, built and
> installed running a pre6 kernel, retried on pre8.
So far it's working for me, using the 3.1.8 userspace utilities and the
kernel support from the standard source tree (instead of David Hinds's
PCMCIA distribution).
$ egrep '^CONFIG.*PCMCIA' /usr/src/linux-2.3.99-pre8/.config
CONFIG_PCMCIA=y
CONFIG_NET_PCMCIA=y
CONFIG_PCMCIA_3C589=m
CONFIG_PCMCIA_3C574=m
CONFIG_PCMCIA_PCNET=m
CONFIG_PCMCIA_SMC91C92=y
CONFIG_PCMCIA_XIRC2PS=m
CONFIG_PCMCIA_NETCARD=y
CONFIG_PCMCIA_SERIAL=y
CONFIG_PCMCIA_SERIAL_CS=m
--
Paul Kimoto <[EMAIL PROTECTED]>
------------------------------
From: Mongoose <[EMAIL PROTECTED]>
Crossposted-To:
comp.os.linux,comp.os.linux.development,comp.os.linux.development.apps,comp.os.linux.misc,comp.os.linux.setup
Subject: Webmin
Reply-To: [EMAIL PROTECTED]
Date: Tue, 16 May 2000 21:08:54 GMT
Has anyone used the system administration program Webmin?
http://www.webmin.com/webmin/
I got this and thought it was a pretty good project. This was along
the lines of the same project I was going to start, but decided not to
since this was pretty much the same program I was going to do. But the
thing is, I havn't seen many people use this. I've asked around about
these types of programs but no one has ever mentioned it. Does anyone
have any opinions on it?
------------------------------
From: Christian Winter <[EMAIL PROTECTED]>
Subject: Re: Can't boot 2.3.99pre8 on Pentium
Date: Tue, 16 May 2000 21:17:07 +0200
bill davidsen <[EMAIL PROTECTED]> schrob:
> I built pre8 on an old Pentium 100, currently running pre6 just fine. On
> boot it dumps registers and locks. Since it isn't working after that I
> can't scroll back to see what it was trying to do at the point it
> failed. Worked perfectly on pre6.
Did you _really_ use the same configuration for kernel build?
Look if you have e.g. forgotten to aktivate "vga mode select"
in 'make config' but a 'vga=xxx' line in lilo.conf.
(It was this reason here).
HTH
Christian
------------------------------
From: Matt Lesko <[EMAIL PROTECTED]>
Subject: Re: Apply the dvd-cd Patch.
Date: Tue, 16 May 2000 17:11:07 -0400
You will want to go to your /usr/src directory. Make sure your linux source
is contained in the sub-directory linux. If not, do a ln -s linux-2.2.15
linux. Then make sure you're *.diff file is in the directory below the linux
directory (/usr/src). At the command line type: patch -p0 < filename.diff
and hopefully everything should work out right. A diff file is the same as a
patch file, so if that doesn't work, find a howto/man/info file on patching
the kernel to fix that problem. Hope to have been of some help
-- Matt Lesko
The Golden Rule: Those with gold rule!
jesper wrote:
> I'm having kernel 2.2.15, and i want to be able to play DVD. Then I found
> out that i should patch my kernel, the file patch for the 2.2.15 kernel
> that i downloaded was in bz2 format by uncompressing it is a *.diff file.
> How should i apply this patch.
> I have already read the kernel-howto, but that did not helped me
>
> Thanks for any help
> Jesper
>
> --
> Posted via CNET Help.com
> http://www.help.com/
------------------------------
From: [EMAIL PROTECTED] (H.Bruijn)
Crossposted-To:
comp.os.linux,comp.os.linux.development,comp.os.linux.development.apps,comp.os.linux.misc,comp.os.linux.setup
Subject: Re: Webmin
Date: 16 May 2000 21:15:12 GMT
Reply-To: [EMAIL PROTECTED]
On Tue, 16 May 2000 21:08:54 GMT, Mongoose allegedly wrote:
> Has anyone used the system administration program Webmin?
>http://www.webmin.com/webmin/
>I got this and thought it was a pretty good project. This was along
>the lines of the same project I was going to start, but decided not to
>since this was pretty much the same program I was going to do. But the
>thing is, I havn't seen many people use this. I've asked around about
>these types of programs but no one has ever mentioned it. Does anyone
>have any opinions on it?
It's pretty good for the newbie, buty to be honoust I only used it to
configure samba when I was experimenting with that. I prefer to edit the
config files myself in most cases, since that 's quicker and allows for
more fine grained control.
Let me rephrase that, it's pretty good, period. The thing is most people
are already sitting either behind the the console, or have root acces
anyway and can then use the native sysadmin tools for their favourite
distribution.
--
Herman
========================================================================
If a trainstation is the place where trains stop, what is a workstation?
========================================================================
Herman Bruijn mail: [EMAIL PROTECTED]
The Netherlands GnuPG key: http://www.bruyn.org/gpgkey
------------------------------
Crossposted-To: comp.os.linux.development.apps,comp.os.linux,comp.os.linux.misc
Date: Tue, 16 May 2000 14:28:17 -0700
From: Doug Schulz <[EMAIL PROTECTED]>
Subject: Finding the status of a process
I have a program that forks a process. I would like the process that
did the forking to be able to get the status of the forked process.
The parent process has the process ID of the forked process. How do I
find what the exit status of the forked process is (if it has exited),
or some piece of information that would allow me to conclude that the
process is still running? Any help is appreciated.
I am using the execvp( ) call after the fork in the child process.
Thanks,
Doug
------------------------------
From: [EMAIL PROTECTED] (Stefaan A Eeckels)
Subject: Re: Windows98 IDE driver screwed up Linux UDMA disk access?
Date: Tue, 16 May 2000 23:41:21 +0200
In article <[EMAIL PROTECTED]>,
[EMAIL PROTECTED] (Paul D. Smith) writes:
> %% Stefan Taferner <[EMAIL PROTECTED]> writes:
>
> st> Windows hardware profile does not change your bios or hardware.
>
> I didn't think that disabling the IDE controller in the hardware profile
> was what gave Linux fits. Indeed, as I said, the problem appeared long
> before I did that.
>
> What appeared to cause Linux to choke was installing the different
> Windows IDE controller driver in the first place. Once I did that and
> rebooted, _neither_ Linux nor Windows would start up anymore.
Did you reboot, or did you power-cycle?
>
> I was able to get Windows to start up by disabling the controller in
> the hardware profile, but that didn't help Linux at all (obviously).
>
> st> tail /var/log/messages
> st> There you should find some tips why it fell back into read-only.
> st> Probably because the filesystem is corrupted.
>
> Hmm. I looked but didn't see anything untoward. I'm not at my system
> now but I'll double-check tonight.
Is the /c partition _really_ read-only, or does it give you
error messages after a write operation whilst still performing it?
>
> st> You can install dosfsck and fsck the windows partition, or do
> st> a file system check of the partition in Windows.
>
> Well, Windows doesn't seem to be complaining about anything, but I'll
> try dosfsck.
It's unlikely that a mount would "fall back" to read-only because of
file system damage.
> I still suspect that whatever installing the Windows controller driver
> did is the same thing that caused Linux to not be able to access the
> disk correctly (or, maybe my disabling UDMA did it somehow--I certainly
> know very little about UDMA--but since I had to do that to get Linux to
> boot it amounts to the same thing).
>
> The question is: what did the Windows driver do to the controller or the
> disk such that when Linux tries to boot it gives that UDMA timeout
> message, then hangs forever? It didn't used to do that. That seems to
> be the real crux of the issue and if I could solve that problem I could
> re-enable UDMA in the BIOS and maybe the drive would work correctly
> again.
You could try to boot from a rescue floppy (something
like tomsrtbt) and see if the problem persists.
There are a couple of IDE settings that can be made persistent.
Seening that you're running a recent kernel, go to the
/proc/ide/ide0/hda directory, and cat settings:
ebola ide0/hda# cat settings
name value min max mode
---- ----- --- --- ----
bios_cyl 1232 0 65535 rw
bios_head 255 0 255 rw
bios_sect 63 0 63 rw
breada_readahead 4 0 127 rw
bswap 0 0 1 r
file_readahead 124 0 2097151 rw
io_32bit 1 0 3 rw
keepsettings 1 0 1 rw
max_kb_per_request 64 1 127 rw
multcount 8 0 8 rw
nice1 1 0 1 rw
nowerr 0 0 1 rw
pio_mode write-only 0 255 w
slow 0 0 1 rw
unmaskirq 1 0 1 rw
using_dma 1 0 1 rw
Use "hdparm" to get a more readable display of the settings:
ebola:~ # hdparm -v /dev/hda
/dev/hda:
multcount = 16 (on)
I/O support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 1 (on)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 1232/255/63, sectors = 19807200, start = 0
Do the same for hdb, and post the output here.
Did you notice the "keepsettings"? It's quite possible that
the new driver enabled DMA, and that your motherboard/drive
combination can't handle it. I'm puzzled that you have UDMA/66
capabilities in a year-old system (AFAIK, one needed to buy
a separate controller card, as all chipsets were UDMA/33 only
in those days --that might explain the 3 IDE controllers).
BTW, put the CD-ROM as slave, and the Linux disk as master on the
second IDE channel, especially if you tend to work a lot with
/c whilst in Linux.
Take care,
--
Stefaan
--
--PGP key available from PGP key servers (http://www.pgp.net/pgpnet/)--
Ninety-Ninety Rule of Project Schedules:
The first ninety percent of the task takes ninety percent of
the time, and the last ten percent takes the other ninety percent.
------------------------------
From: David Wragg <[EMAIL PROTECTED]>
Subject: Re: ANSI C & void main()
Date: 16 May 2000 20:05:44 +0000
"Mark Graybill" <[EMAIL PROTECTED]> writes:
> David Wragg wrote in message ...
> > [snip]
> >
> >That isn't what linkage means in "the standard" (ISO C++ 98). How can
> >you expect to interpret any document correctly when you don't known
> >what the words it uses mean?
>
> [snip]
>
> It seems to be common practice to make such statements as you did above (I
> had one poster attack my English, citing I shouldn't be trusted around
> computers because of it.)
I have no basis to judge your competency in any field. But in this
thread you have made statements that are absolutely typical of a C and
C++ standards newbie. Mentioning K&R is a classic. So is discussing
what typical compilers would do with a piece of code. Somehow
sections of C++98 got quoted rather than the more relevant C90 or C99.
I don't think you started that, but you certainly ran with it without
being explicit about which standard you were referring to.
> My purpose is not to win an argument, but rather
> explore and report.
>
> There is a flora of interpretations given so far, and although we each
> believe our own to be true, I am waiting to get the official interpretation
> from ANSI. When I receive my response from ANSI, I will post it.
Good luck. ANSI have taken six months so far to ratify ISO C99 due to
a silly procedural complication.
Whether or not you get a satisfactory response from ANSI, you might
like to take your case to comp.std.c++ or comp.std.c as appropriate.
Experts on the standards, including several members of the relevant
committees, read those groups.
David Wragg
------------------------------
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End of Linux-Development-System Digest
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