Linux-Development-Sys Digest #850, Volume #6 Sun, 20 Jun 99 19:14:09 EDT
Contents:
Re: WHAT ARE THESE TERMS SUPPOSE TO MEAN (Kevin Burton)
Re: using C++ for linux device drivers (Frank Sweetser)
Re: using C++ for linux device drivers (Frank Sweetser)
Re: WHAT ARE THESE TERMS SUPPOSE TO MEAN (Gianni Mariani)
Re: how to get pathname from process ID (Konrad Mieredorff)
Re: TAO: the ultimate OS (Alexander Viro)
Re: TAO: the ultimate OS (void)
Ultimate OS (RaiX)
Re: using C++ for linux device drivers (Gianni Mariani)
Re: WHAT ARE THESE TERMS SUPPOSE TO MEAN (Jerry Lapham)
Re: Needed: Driver for Motorola V.90 PCI modem (Jerry Lapham)
Re: Embedded Linux Question ("Sarlock T.")
Re: WHAT ARE THESE TERMS SUPPOSE TO MEAN (John Hiser)
Re: Pinning a thread to a processor (Tor Arntsen)
USR OEM Alana DFV PCI V.90 modem (cookies)
Re: WHAT ARE THESE TERMS SUPPOSE TO MEAN (Peter Mardahl)
Re: TAO: the ultimate OS (Stefaan A Eeckels)
----------------------------------------------------------------------------
From: Kevin Burton <[EMAIL PROTECTED]>
Subject: Re: WHAT ARE THESE TERMS SUPPOSE TO MEAN
Date: Sun, 20 Jun 1999 13:16:49 -0700
"hz" is cycles per second. I am not sure if HZ is used in the same
context.
"Santosh H." wrote:
>
> Hi,
> Sorry for shouting.But i'm really fed up with trying to find out what
> this means
> 1] jiffy
> 2] HZ
>
> I'd be really grateful for some help.
>
> pls reply to [EMAIL PROTECTED]
>
> thanx in advance
>
> Santosh
------------------------------
From: Frank Sweetser <[EMAIL PROTECTED]>
Subject: Re: using C++ for linux device drivers
Date: 20 Jun 1999 15:51:41 -0400
[EMAIL PROTECTED] (Don Baccus) writes:
> In article <[EMAIL PROTECTED]>,
> Frank Sweetser <[EMAIL PROTECTED]> wrote:
> >Justin Vallon <[EMAIL PROTECTED]> writes:
>
> >> void *operator new(size_t s) { return malloc(s); /* kmalloc, etc */ }
> >> void operator delete(void *p) { free(p); }
>
> >...which is a higher-overhead version of
>
> >#define new((x)) malloc((x))
> >#define delete((x)) free((x))
>
> Any decent compiler will generate the proper definition
> in-line, giving exactly the same code as the #define
> hack.
in a normal program, yes, with sufficient optimization enabled. however,
the kernel is *not* a normal program (note that the subject is writing
linux device drivers). as such, the optmization level of gcc is left at
-O2, which does not enable automatic inlining of functions. any
functions deemed worthy of inlining are then manually declared to be
inlined by extra gcc-specific declarations.
--
Frank Sweetser rasmusin at wpi.edu fsweetser at blee.net | PGP key available
paramount.ind.wpi.edu RedHat 5.2 kernel 2.2.5 i586 | at public servers
It is my job in life to travel all roads, so that some may take the road
less travelled, and others the road more travelled, and all have a
pleasant day.
-- Larry Wall in <[EMAIL PROTECTED]>
------------------------------
From: Frank Sweetser <[EMAIL PROTECTED]>
Subject: Re: using C++ for linux device drivers
Date: 20 Jun 1999 16:02:43 -0400
[EMAIL PROTECTED] (Nathan Myers) writes:
> Frank Sweetser <[EMAIL PROTECTED]> wrote:
> >Justin Vallon <[EMAIL PROTECTED]> writes:
> >> [EMAIL PROTECTED] (Alexander Viro) writes:
> >> > In article <7kdqj9$l1o$[EMAIL PROTECTED]>, <[EMAIL PROTECTED]> wrote:
> >> > > I am working a sound driver for linux (I will probably use OSS).I
> >> > >am planning to use C++, instead of C.
> >>
> >> void *operator new(size_t s) { return malloc(s); /* kmalloc, etc */ }
> >> void operator delete(void *p) { free(p); }
> >
> >...which is a higher-overhead version of
> >
> >#define new((x)) malloc((x))
> >#define delete((x)) free((x))
>
> Frank, you are confused beyond salvation on this point.
> Best drop it.
exactly how am i confused? (honest question, i'm not trying to flame...)
the only overhead to which i was referring is the overhead of calling a
function that does nothing but call the function you really want. and yes,
you do want to worry about that kind of optimization in the kernel code at
times. note that this will not simply be inlined by the compiler in the
case of the kernel unless you tell it to.
> >> Compile with -nostdinc++ -fno-exceptions.
> >>
> >> Static constructors may need a C++ link phase, or you could warn that
> >> C++ static constructors will not be executed.
> >
> >don't forget about name mangling, call by reference, the whole
> >private/public/protected mess...
>
> Name mangling is dealt with by 'extern "C"'.
hrm... IIRC, there were some issues that came up with the last time this
matter got hashed out regarding exporting symbols from C++ code - ie, going
the other way. i may be misremembering, though...
> Call-by-reference is a non-issue; no kernel function or callback uses it.
another feature of C++ that can't be used.
> There is no such thing as a "private/public/protected" mess.
> Those keywords have no effect on the emitted object code.
another feature of C++ that can't be used.
> That they are keywords at all might break some kernel headers.
i guess my biggest point here is - once you take away all of the extra
feautures that won't work or don't make sense in the kernel context, what
advantages does C++ realy have for writing a kernel module?
--
Frank Sweetser rasmusin at wpi.edu fsweetser at blee.net | PGP key available
paramount.ind.wpi.edu RedHat 5.2 kernel 2.2.5 i586 | at public servers
It is my job in life to travel all roads, so that some may take the road
less travelled, and others the road more travelled, and all have a
pleasant day.
-- Larry Wall in <[EMAIL PROTECTED]>
------------------------------
From: Gianni Mariani <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
Subject: Re: WHAT ARE THESE TERMS SUPPOSE TO MEAN
Date: Sun, 20 Jun 1999 20:19:52 GMT
jiffy is a colloquialism for the adjective briskly
Santosh H. wrote:
> Hi,
> Sorry for shouting.But i'm really fed up with trying to find out what
> this means
> 1] jiffy
> 2] HZ
>
> I'd be really grateful for some help.
>
> pls reply to [EMAIL PROTECTED]
>
> thanx in advance
>
> Santosh
------------------------------
From: Konrad Mieredorff <[EMAIL PROTECTED]>
Subject: Re: how to get pathname from process ID
Date: Sun, 20 Jun 1999 22:37:48 +0200
Soohyung Lee wrote:
>
> How can I get the full pathname of a process from its pid ?
>
> Can you please help me ?
> I really need your help .
> Thanks in advance .
>
> - Lee -
Due to hard links more than one path to a file can exists.
Besides from that there is an entry in the proc-filesystem that looks
like what you want: /proc/PID/exe
------------------------------
From: [EMAIL PROTECTED] (Alexander Viro)
Crossposted-To: alt.os.linux,comp.os.linux.advocacy,comp.os.misc,comp.unix.advocacy
Subject: Re: TAO: the ultimate OS
Date: 20 Jun 1999 16:25:29 -0400
In article <[EMAIL PROTECTED]>,
Konstantin Koll <[EMAIL PROTECTED]> wrote:
>Each user gets it's own home directory with NO subdirs. You can dump 41^8 files
>in there (8 characters allowed for DOS files with 41 different symbols allowed).
>Sorry, I don't have much experience with automatic file generation (screenshot
>program ?) However, it's no problem to keep track and find your files back !
>I've
>about 700 files in my home dir and have any of them at hand in some seconds.
>Remember, you hardly work with a list that shows ALL files at the same time, but
>you only get a limited selection (show me all images, show me all sounds, show
>me the texts that have been modified the last days).
Ouch... That's fine until the moment when you got several projects and have to
scratch your head - WTF did FOOBAR.FOR come from? Or, better yet, you are going
to print the parts of this friggin' expert system that are responsible for
processing the results of gas chromatography and have to recall which 5 (or
was it 6?) files of LISP code are relevant. Happy, happy, joy, joy... (I'm
not making that up - been there, done that, got a title "Flaming Death" from
chemists who stood behind and kept whining about deadlines).
--
"You're one of those condescending Unix computer users!"
"Here's a nickel, kid. Get yourself a better computer" - Dilbert.
------------------------------
From: [EMAIL PROTECTED] (void)
Crossposted-To: alt.os.linux,comp.os.linux.advocacy,comp.os.misc,comp.unix.advocacy
Subject: Re: TAO: the ultimate OS
Date: 20 Jun 1999 20:50:17 GMT
On 20 Jun 1999 17:04:10 GMT, Terry Murphy <[EMAIL PROTECTED]> wrote:
>
>If the OS provides optimized record services, then they should be good
>for most tasks. I think that is a much cleaner solution than the Unix way,
>where everybody who needs a database implements it on their own. Each
>program has its own data, and the code to read that data is unique to
>the program, which IMHO, is very sloppy.
That's what libraries are for.
--
Ben
"The world is conspiring in your favor." -- de la Vega
------------------------------
From: RaiX <[EMAIL PROTECTED]>
Subject: Ultimate OS
Date: Sun, 20 Jun 1999 22:59:28 +0200
Linux with netscape as GUI.
That's it..
Regs RaiX
------------------------------
From: Gianni Mariani <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
Subject: Re: using C++ for linux device drivers
Date: Sun, 20 Jun 1999 20:35:44 GMT
I agree that it's time to support a limited level of C++ functionality
in the kernel.
It seems that the C++ compilers have matured so that there is very good
portability and that the base C++ knowledge has reached a level that many
people can be very productive.
Until recently I was adament that C was all you needed but I have
recently
done some projects that showed me I was wrong. The C++ compiler is
just as effective as a regular C compiler in creating excellent code and
it's much easier to design complex objects and re-using code efficiently.
It's time to use C++ for kernel code !
Flame away ...
[EMAIL PROTECTED] wrote:
> Hi all,
>
> I am working a sound driver for linux (I will probably use OSS).I
> am planning to use C++, instead of C. Has anyone used C++ before for
> kernel/device driver programming for linux. If so what are the
> complications with using C++. I heard that C++ needs some OS support,
> especially for calls like "new", "delete" and stuff like that.
>
> Thanks in advance
>
> Ram
>
> Sent via Deja.com http://www.deja.com/
> Share what you know. Learn what you don't.
------------------------------
From: [EMAIL PROTECTED] (Jerry Lapham)
Subject: Re: WHAT ARE THESE TERMS SUPPOSE TO MEAN
Date: Sun, 20 Jun 1999 16:53:20 -0400
In <Pine.SOL.3.96.990620233631.14423B-100000@giasbga>, on 06/20/99
at 11:41 PM, "Santosh H." <[EMAIL PROTECTED]> said:
> Sorry for shouting.But i'm really fed up with trying to find out what
> this means
> 1] jiffy
> 2] HZ
I can't be sure without seeing the terms in context, but in common
American English vernacular, "jiffy" is a small amount of time, as in
"I'll be with you in a jiffy." "HZ" is the abbreviation for "Hertz",
which in electronics used to be called a "cycle" before they decided to
name it after someone.
-Jerry
--
============================================================
Jerry Lapham, Monroe, OH
E-Mail: [EMAIL PROTECTED]
Written Sunday, June 20, 1999 - 04:52 PM (EDT)
============================================================
MR/2 Ice tag: Dyslexics untie!
------------------------------
From: [EMAIL PROTECTED] (Jerry Lapham)
Subject: Re: Needed: Driver for Motorola V.90 PCI modem
Date: Sun, 20 Jun 1999 16:44:37 -0400
In <vBYa3.3795$[EMAIL PROTECTED]>, on 06/20/99
at 02:45 AM, "SweetGear" <[EMAIL PROTECTED]> said:
> Needed: Driver for Motorola V.90 PCI modem
> Does it exist?
Probably not. Only software modems require "drivers" and software modems
are usually only supported in Windows. Does it say "HCF" or "HSF"
anywhere on the box? If so, it's a software modem and won't work in DOS,
OS/2, Linux, BeOS, etc. BTW, most PCI modems are software modems.
-Jerry
--
============================================================
Jerry Lapham, Monroe, OH
E-Mail: [EMAIL PROTECTED]
Written Sunday, June 20, 1999 - 04:44 PM (EDT)
============================================================
MR/2 Ice tag: Dyslexics untie!
------------------------------
From: "Sarlock T." <sarlock@no!spam.twcny.rr.com>
Crossposted-To: comp.os.linux.m68k,sci.electronics.design,sci.electronics.misc
Subject: Re: Embedded Linux Question
Date: Sun, 20 Jun 1999 17:57:05 -0400
Any idea where I can find good information on this particular product?
Wolfgang Denk wrote in message ...
>Another option instead of an Intel x86 architecture is to go with a
>Motorola Embedded Controller, for instance one of the MPC8xx CPUs.
>
>The smallest "board" I could lay hands on so far is just 44 mm x 54
>mm (1.7" x 2.1"), a bit smaller than half a credit card. It has up to
>64 MB RAM, 8 MB FLASH, 2 x RS232, parallel port, TP ethernet.
>
>And yes, I have Linux (2.2.5) running on it...
>
>Software Engineering: Embedded and Realtime Systems, Embedded Linux
>Phone: (+49)-8142-4596-87 Fax: -88 Home: -86 Email: [EMAIL PROTECTED]
>panic: kernel trap (ignored)
------------------------------
From: John Hiser <[EMAIL PROTECTED]>
Subject: Re: WHAT ARE THESE TERMS SUPPOSE TO MEAN
Date: Sun, 20 Jun 1999 17:56:26 -0400
"Santosh H." wrote:
>
> 1] jiffy
If I recall properly, this is not only a colloquillism, but also a
set amount of time. Something like the time it takes light to
cross the lowest hydrogen orbital. The memory fades...
> 2] HZ
Cycles per second. (As per other posts.)
-John
------------------------------
From: [EMAIL PROTECTED] (Tor Arntsen)
Subject: Re: Pinning a thread to a processor
Date: Sat, 19 Jun 1999 21:22:04 GMT
In article <7kge61$[EMAIL PROTECTED]>,
[EMAIL PROTECTED] (Byron A Jeff) writes:
>Um not to be too totally obnoxious, but if you modified the Linux kernel and
>distributed the changes in any way, then your code must be GPL and you're
>obligated to release the source.
To those he distributed his changed version to only.
-Tor
------------------------------
From: cookies <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.hardware,redhat.hardware.arch.intel
Subject: USR OEM Alana DFV PCI V.90 modem
Date: 20 Jun 1999 22:30:51 GMT
Hi, all!
I got a USR OEM Alana DFV PCI V.90 modem, I didn't find it in the list of
Winmodem. But I am not sure it will work under Linux 5.2. is there anyone
who can help me?
Yours,
John
================== Posted via SearchLinux ==================
http://www.searchlinux.com
------------------------------
From: [EMAIL PROTECTED] (Peter Mardahl)
Subject: Re: WHAT ARE THESE TERMS SUPPOSE TO MEAN
Date: 20 Jun 1999 15:32:42 -0700
In article <Pine.SOL.3.96.990620233631.14423B-100000@giasbga>,
Santosh H. <[EMAIL PROTECTED]> wrote:
>Hi,
> Sorry for shouting.But i'm really fed up with trying to find out what
>this means
>1] jiffy
>2] HZ
A "jiffy" in Linux kernelspeak is a unit of time.
HZ is Hertz, and usually has to do with the clock tick.
Here's a def for jiffies I found:
to disk. The value is expressed in jiffies (clockticks), the
number of jiffies per second is 100. Age_buffer is the
maximum age for data blocks, while age_super is for
filesystems meta data.
It was in:
/usr/src/linux-2.2.6/Documentation/proc.txt
PeterM
------------------------------
From: [EMAIL PROTECTED] (Stefaan A Eeckels)
Crossposted-To: alt.os.linux,comp.os.linux.advocacy,comp.os.misc,comp.unix.advocacy
Subject: Re: TAO: the ultimate OS
Date: 20 Jun 1999 22:26:19 GMT
In article <7kj6ua$hjp$[EMAIL PROTECTED]>,
[EMAIL PROTECTED] (Terry Murphy) writes:
> In article <7kg38f$kbc$[EMAIL PROTECTED]>,
> Stefaan A Eeckels <[EMAIL PROTECTED]> wrote:
>
> The issue of whether an OS should be mainframe-like or Unix-like
> is actually pretty interesting. Mainframe OS'es had lots of features,
> but they were big and slow for their time.
Slow for their time --do you really mean that they were suboptimal
for the hardware they were running on? I've worked on mainframes,
and I can tell you that they were bloody fast, given the rather
feeble CPU and memory resources at their disposal.
> Unix came in and showed
> the world, that an OS did not have to be big, and stripped all
> "extraneous" functionality.
If you say OS, I gather you mean "kernel". The UNIX kernel might not
be big, but UNIX (the kernel and the commands) offers *a lot* more
functionality than any other OS. You might not like the idea of running
as much as possible in user space, but the comment above is just plain
wrong.
> Meanwhile, hardware grew, big time. In
> hindsight, though, it can be argued that the mainframe OS'es, with their
> insistence of a sheer number of features rather just elegance of
> simplicity (i.e. Unix), were ahead of their time. It was not until
> recently that they could be implemented to perform well.
This is silly. Have you ever used a mainframe OS (MVS or MCP or George
or VME, or even TOPS)? MVS is *not* a mainframe OS, it's a mini OS.
> Windows NT is
> much more of a mainframe class OS than Unix is -- however, it has been
> very influenced by Unix (e.g. files are streams of bytes), so it ends
> up falling into a somewhat in-between class, which is probably why a lot
> of people do not like it.
So the defining quality of an OS is support for structured files?
That's risible.
>>It was easier to port UNIX than to write an OS from scratch. The
>>fact that the principals of comapnies such as Sun cut their teeth
>>on UNIX at Berkeley (and liked it, I guess) was also a significant
>>factor. BTW, the people who did BSD and SunOS *are* professional
>>software engineers (that's at least what their degree says).
>
>>Today, hardware companies do not even dream of developing an OS, and
>>no longer consider porting UNIX. They design their hardware to be
>>compatible with Windows, and write drivers.
>
> Perhaps in your Microsoft-dominated fantasy world. The fact is there are
> no less than five Unix's being slated to run on IA-64 (off the top of
> my head, I can think of Tru64, Solaris, IRIX, HP-UX, and SCO...plus
> Linux...I forget if AIX is in the works). I'm not even sure there
> are that many major architectures which do NOT run Unix, besides some
> of the mainframe systems.
You definitely have a problem grokking English. I said: "hardware companies
do not even dream of developing an OS", which is what they routinely did for
mainframes and minis in the sixties and seventies.
To wit:
Digital UNIX: a port of an existing code base.
Solaris: a port of an existing code base
IRIX: a port of an existing code base
HP-UX: a port of an existing code base
SCO: idem, and SCO is not even a hardware company
Windows: idem, and MS is not a hardware company.
Linux: a port of an existing code base.
Conclusion: for the first truly new processor Intel deigns to
launch in almost 20 years, *nobody* develops a new OS.
>>NFS is not a great protocol, granted. Pretending that SMB is any
>>better displays your profound lack of knowledge.
>
> I am not saying SMB is a great protocol. I am merely saying fundamental
> filesystem features such as mandatory file locking work in it (as well
> as DECnet), but not in NFS.
My comment stands. File locking in SMB is difficult, and many applications
(including MS ones) make a terrible hash of it. Not so much different from
NFS (the protocol provides for locking, but most implementations are rather
lousy).
>>So what? The basic UNIX file system is designed to store lots of small
>>files. When your average mainframe OS was designed, disk space was so
>>expensive small text files were stored on paper
>
> I understand that, but this was 30 years ago. Today, most users (whatever
> that means) work with large, structured files such as Word documents,
> Access databases, Excel Spreadsheets, etc. The era of the small file
> is over. And, as I noted above, we now have the hardware to support such
> use.
Who's living in an MS-centric world, now ;-)
You really want to build support for application-level data structures
into the OS? Since when is a library not good enough?
>>There's no guarantee that an OS provided index-sequential file will
>>be the best support for a relational DBMS (in fact, it isn't).
>>Similarly, the locking features of the OS might not be the best
>>choice for a DBMS (in fact, they aren't).
>
> If the OS provides optimized record services, then they should be good
> for most tasks.
Dream on. For one, they won't be good enough for MS Word.
> I think that is a much cleaner solution than the Unix way,
> where everybody who needs a database implements it on their own.
And where companies like Oracle, Informix and Sybase know a lot
more about DBMSes than the people designing the OS.
> Each
> program has its own data, and the code to read that data is unique to
> the program, which IMHO, is very sloppy.
That's a fairly accurate description of the latest fad in programming,
Object Orientation. And quite removed from the filter-based approach
typical for UNIX.
> The same is true of the Unix
> idea of config files (vs. various database configuration setups in most
> other OS'es).
Oh no, not YACRF (Yet Another Clueless Registry Fan).
--
Stefaan
--
PGP key available from PGP key servers (http://www.pgp.net/pgpnet/)
___________________________________________________________________
Perfection is reached, not when there is no longer anything to add,
but when there is no longer anything to take away. -- Saint-Exup�ry
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End of Linux-Development-System Digest
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