* Re: [9fans] Re: Solaris thread scheaduling
@ 2000-08-18 15:34 rob pike
[not found] ` <rob@plan9.bell-labs.com>
0 siblings, 1 reply; 187+ messages in thread
From: rob pike @ 2000-08-18 15:34 UTC (permalink / raw)
To: 9fans
What, we should use uncooperative threads?
Adversarial threads? Anarchic threads?
I guess I don't know the terminology. If POSIX threads
are a good thing, perhaps I don't want to know what they're
better than.
-rob
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] new versions of graphics programs?
@ 2000-09-07 21:57 rob pike
2000-09-07 22:50 ` Jim Choate
0 siblings, 1 reply; 187+ messages in thread
From: rob pike @ 2000-09-07 21:57 UTC (permalink / raw)
To: 9fans
I started on a couple of the tools. Since the PIC format is
now largely irrelevant - the standard image format captures
much of its capabilities - it seemed worth retiring the fb
software. Retiring it also helped keep the distribution smaller
and easier to assemble. But clearly, some of the tools in
fb/ are worth having.
I worked on a couple of the tools and stumbled into original
bugs that I didn't see how to fix, so that project has stalled.
The shipped gif and jpg tools and the iconv program should
address some of the lower-level needs. Higher-level
image processing is a project for a dedicated soul; it's a big
job.
-rob
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] could those of you who have students check this out for
@ 2001-06-09 17:22 forsyth
2001-06-09 18:50 ` [9fans] Re: the 'science' in computer science andrey mirtchovski
0 siblings, 1 reply; 187+ messages in thread
From: forsyth @ 2001-06-09 17:22 UTC (permalink / raw)
To: 9fans
>>our computer science department has strong roots in algorithmics.
that might be true, but do the students, in the main, write programs
except those they are required to do for assessments and projects?
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] Re: the 'science' in computer science
2001-06-09 17:22 [9fans] could those of you who have students check this out for forsyth
@ 2001-06-09 18:50 ` andrey mirtchovski
2001-06-09 17:56 ` Boyd Roberts
` (3 more replies)
0 siblings, 4 replies; 187+ messages in thread
From: andrey mirtchovski @ 2001-06-09 18:50 UTC (permalink / raw)
To: 9fans
unfortunately dan cross is very right in his analysis -- most of the
students care not for algorithmics. the three classes i listed are the most
hated ones (together with the "Systems Programming and Introduction to
Operating Systems", the UNIX class) simply because they actually make the
students think...
there are the occasional bad apples who explore the field, write code
and are interested in the 'science' part of 'computer science'.. the others
are happy to get their 3 year degrees and drone off to the job market.
andrey
On Sat, 9 Jun 2001 forsyth@caldo.demon.co.uk wrote:
> >>our computer science department has strong roots in algorithmics.
>
> that might be true, but do the students, in the main, write programs
> except those they are required to do for assessments and projects?
>
>
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-09 18:50 ` [9fans] Re: the 'science' in computer science andrey mirtchovski
@ 2001-06-09 17:56 ` Boyd Roberts
2001-06-11 8:27 ` pac
2001-06-11 15:19 ` Dan Cross
2001-06-12 0:09 ` Scott Merrilees
` (2 subsequent siblings)
3 siblings, 2 replies; 187+ messages in thread
From: Boyd Roberts @ 2001-06-09 17:56 UTC (permalink / raw)
To: 9fans
i don't think i'd go so far to call it a science -- more like an art.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-09 17:56 ` Boyd Roberts
@ 2001-06-11 8:27 ` pac
2001-06-11 15:19 ` Dan Cross
1 sibling, 0 replies; 187+ messages in thread
From: pac @ 2001-06-11 8:27 UTC (permalink / raw)
To: 9fans
IMHO, CS is to mathematics, as medicine is to biology; personally, I call them both "technology" :-(
Peter
--
Peter A. Cejchan
Dept. Paleobiology, Inst. Geology Acad. Sci.,
Rozvojova 135, Prague 6
CZ-16502 Czech Republic
<cej@cejchan.gli.cas.cz>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A plea:
Please, consider your support to the Public Library of Science initiative at
http://www.publiclibraryofscience.org
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-09 17:56 ` Boyd Roberts
2001-06-11 8:27 ` pac
@ 2001-06-11 15:19 ` Dan Cross
2001-06-11 21:43 ` Boyd Roberts
[not found] ` <0cb501c0f2bf$97cacea0$e8b7c6d4@SOMA>
1 sibling, 2 replies; 187+ messages in thread
From: Dan Cross @ 2001-06-11 15:19 UTC (permalink / raw)
To: 9fans
In article <041601c0f10d$72dabaa0$e8b7c6d4@SOMA> you write:
>i don't think i'd go so far to call it a science -- more like an art.
Okay, this is getting way off topic for 9fans, but, let me ask
this: at the real abstract, pure level, is science any different
at all from art? I contend that they're one and the same.
- Dan C.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-11 15:19 ` Dan Cross
@ 2001-06-11 21:43 ` Boyd Roberts
[not found] ` <0cb501c0f2bf$97cacea0$e8b7c6d4@SOMA>
1 sibling, 0 replies; 187+ messages in thread
From: Boyd Roberts @ 2001-06-11 21:43 UTC (permalink / raw)
To: 9fans
From: "Dan Cross" <cross@math.psu.edu>
> Okay, this is getting way off topic for 9fans, but, let me ask
> this: at the real abstract, pure level, is science any different
> at all from art? I contend that they're one and the same.
nonsense. physics is a science. i can predict things with it.
does computer science predict anything for me? i'll give you that
it does have an axiom that states:
you will be plagued by bugs in any development effort
but that doesn't really predict anything in anything that vaguely
approaches a _law_ of physics -- pick one. eg. the prohibition
of speeds greater than the of speed of light.
comp sci is more like an engineering discipline with very few
fundamentals.
^ permalink raw reply [flat|nested] 187+ messages in thread
[parent not found: <0cb501c0f2bf$97cacea0$e8b7c6d4@SOMA>]
* Re: [9fans] Re: the 'science' in computer science
[not found] ` <0cb501c0f2bf$97cacea0$e8b7c6d4@SOMA>
@ 2001-06-11 22:43 ` paurea
2001-06-12 14:18 ` Dan Cross
0 siblings, 1 reply; 187+ messages in thread
From: paurea @ 2001-06-11 22:43 UTC (permalink / raw)
To: 9fans
Boyd Roberts writes:
> From: "Boyd Roberts" <boyd@fr.inter.net>
> Subject: Re: [9fans] Re: the 'science' in computer science
> Date: Mon, 11 Jun 2001 23:43:45 +0200
>
> From: "Dan Cross" <cross@math.psu.edu>
> > Okay, this is getting way off topic for 9fans, but, let me ask
> > this: at the real abstract, pure level, is science any different
> > at all from art? I contend that they're one and the same.
>
> nonsense. physics is a science. i can predict things with it.
>
> does computer science predict anything for me? i'll give you that
> it does have an axiom that states:
>
> you will be plagued by bugs in any development effort
>
> but that doesn't really predict anything in anything that vaguely
> approaches a _law_ of physics -- pick one. eg. the prohibition
> of speeds greater than the of speed of light.
>
> comp sci is more like an engineering discipline with very few
> fundamentals.
¿Would you say Math is a science?.
Its theoretical foundations are based on turing machines...
(I believe all physics are written in math simbols...)
--
Saludos,
Gorka
"Curiosity sKilled the cat"
--
/"\
\ / ascii ribbon campaign - against html mail
X - against ms attachments
/ \
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-11 22:43 ` paurea
@ 2001-06-12 14:18 ` Dan Cross
2001-06-12 15:50 ` Boyd Roberts
0 siblings, 1 reply; 187+ messages in thread
From: Dan Cross @ 2001-06-12 14:18 UTC (permalink / raw)
To: 9fans
In article <15141.18819.7956.967025@nido.hilbert.space> you write:
>Would you say Math is a science?.
>Its theoretical foundations are based on turing machines...
Woah, they are? Mathematics, and many of its theoretical foundations,
existed for a really long time before Alan Turing was born....
>(I believe all physics are written in math simbols...)
Basically, but each discipline seems to invent its own psuedo-
mathematical notation. Not necessarily a bad thing, but it can
get really confusing (cf. i in mathematics vs. j in engineering).
- Dan C.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-09 18:50 ` [9fans] Re: the 'science' in computer science andrey mirtchovski
2001-06-09 17:56 ` Boyd Roberts
@ 2001-06-12 0:09 ` Scott Merrilees
2001-06-12 0:16 ` Boyd Roberts
[not found] ` <0cc301c0f2c0$78949560$e8b7c6d4@SOMA>
2001-06-16 23:34 ` Matt
3 siblings, 1 reply; 187+ messages in thread
From: Scott Merrilees @ 2001-06-12 0:09 UTC (permalink / raw)
To: 9fans
>unfortunately dan cross is very right in his analysis -- most of the
>students care not for algorithmics. the three classes i listed are the most
>hated ones (together with the "Systems Programming and Introduction to
>Operating Systems", the UNIX class) simply because they actually make the
>students think...
>
>there are the occasional bad apples who explore the field, write code
>and are interested in the 'science' part of 'computer science'.. the others
>are happy to get their 3 year degrees and drone off to the job market.
>
>andrey
Then you have the occasional CS dept / Computer Centre with a computer
usage policy that probihits all use of the univerity computer systems
except for specific course work.
Sm
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-12 0:09 ` Scott Merrilees
@ 2001-06-12 0:16 ` Boyd Roberts
2001-06-12 0:42 ` Scott Merrilees
0 siblings, 1 reply; 187+ messages in thread
From: Boyd Roberts @ 2001-06-12 0:16 UTC (permalink / raw)
To: 9fans
> Then you have the occasional CS dept / Computer Centre with a computer
> usage policy that probihits all use of the univerity computer systems
> except for specific course work.
yeah, but some of us got around that and the more you got around
it the more you learned -- the useful stuff.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-12 0:16 ` Boyd Roberts
@ 2001-06-12 0:42 ` Scott Merrilees
2001-06-12 1:08 ` Boyd Roberts
0 siblings, 1 reply; 187+ messages in thread
From: Scott Merrilees @ 2001-06-12 0:42 UTC (permalink / raw)
To: 9fans
>> Then you have the occasional CS dept / Computer Centre with a computer
>> usage policy that probihits all use of the univerity computer systems
>> except for specific course work.
>boyd:
>yeah, but some of us got around that and the more you got around
>it the more you learned -- the useful stuff.
Very true, but the above CS attitude encourages the production of
drones, while discouraging and even punishing those with the audacity
to try and do some self directed learning.
Sm
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-12 0:42 ` Scott Merrilees
@ 2001-06-12 1:08 ` Boyd Roberts
0 siblings, 0 replies; 187+ messages in thread
From: Boyd Roberts @ 2001-06-12 1:08 UTC (permalink / raw)
To: 9fans
> Very true, but the above CS attitude encourages the production of
> drones, while discouraging and even punishing those with the audacity
> to try and do some self directed learning.
i don't disagree, but when you had 2000 students and one 11/780 for
all of them (even with share/hacks giving you a maximum of 128
simultaneous student logins) i guess something had to be done.
more resources would have been nice.
on the other hand, it was always a nice clause to use on password
crackers and others nuisances.
^ permalink raw reply [flat|nested] 187+ messages in thread
[parent not found: <0cc301c0f2c0$78949560$e8b7c6d4@SOMA>]
* Re: [9fans] Re: the 'science' in computer science
[not found] ` <0cc301c0f2c0$78949560$e8b7c6d4@SOMA>
@ 2001-06-12 14:12 ` Dan Cross
0 siblings, 0 replies; 187+ messages in thread
From: Dan Cross @ 2001-06-12 14:12 UTC (permalink / raw)
To: 9fans
In article <0cc301c0f2c0$78949560$e8b7c6d4@SOMA> you write:
>nonsense. physics is a science. i can predict things with it.
I can predict things with computer science as well: the average
and worst-case running times of an algorithm, for instance, or
the amount of memory used by activation records in a recursive
algorithm.
>does computer science predict anything for me? i'll give you that
>it does have an axiom that states:
>
> you will be plagued by bugs in any development effort
This is a software engineering maxim. Speaking of which.... There
are ``laws'' of software engineering that are kind of like laws of
physics. Add more programmers to a late project, and it gets later;
etc.
>but that doesn't really predict anything in anything that vaguely
>approaches a _law_ of physics -- pick one. eg. the prohibition
>of speeds greater than the of speed of light.
The Church-Turing thesis; NP-complete problems; the halting problem,
just to name a few.
>comp sci is more like an engineering discipline with very few
>fundamentals.
Maybe, but that wasn't even my point.
- Dan C.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-09 18:50 ` [9fans] Re: the 'science' in computer science andrey mirtchovski
` (2 preceding siblings ...)
[not found] ` <0cc301c0f2c0$78949560$e8b7c6d4@SOMA>
@ 2001-06-16 23:34 ` Matt
2001-06-28 21:29 ` Boyd Roberts
3 siblings, 1 reply; 187+ messages in thread
From: Matt @ 2001-06-16 23:34 UTC (permalink / raw)
To: 9fans
My friend is on his third year (of 4) of his Computer Science Degree.
I know they've covered Assembler, Java, C++ and Databases.
I mentioned to him that Dennis Ritchie posted to 9fans thinking he might be
interested.
"Who?"
I didn't bother saying
"Those who do not understand Unix are doomed to reinvent it - poorly..."
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-16 23:34 ` Matt
@ 2001-06-28 21:29 ` Boyd Roberts
2001-06-28 22:03 ` Matt
0 siblings, 1 reply; 187+ messages in thread
From: Boyd Roberts @ 2001-06-28 21:29 UTC (permalink / raw)
To: 9fans
> I know they've covered Assembler, Java, C++ and Databases.
surely s/he could have picked a 5th worthless subject...
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-28 21:29 ` Boyd Roberts
@ 2001-06-28 22:03 ` Matt
2001-06-28 23:20 ` George Michaelson
2001-06-29 4:30 ` Lucio De Re
0 siblings, 2 replies; 187+ messages in thread
From: Matt @ 2001-06-28 22:03 UTC (permalink / raw)
To: 9fans
----- Original Message -----
From: "Boyd Roberts" <boyd@fr.inter.net>
To: <9fans@cse.psu.edu>
Sent: Thursday, June 28, 2001 10:29 PM
Subject: Re: [9fans] Re: the 'science' in computer science
> > I know they've covered Assembler, Java, C++ and Databases.
>
> surely s/he could have picked a 5th worthless subject...
i think that's saved up for the final year
He constantly amazes us (his friends) with his computer cluelessness.
Like finding it difficult to persuade him that his overclocked celeron might
be struggling to execute the tcp/ip stack while he was trying to play
high-end games.
Or helping him install a windows based web proxy (literally double clicking
on setup.exe)
I remember they used MS Access for their database.
We had a CS graduate come for an interview. He was clearly a bit clueless.
The questions were scaled down to make him feel a bit better when he left.
"What is a hexadecimal number?"
"A combination of numbers and letters"
He had a nice suit on though.
M
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-28 22:03 ` Matt
@ 2001-06-28 23:20 ` George Michaelson
2001-06-29 21:27 ` Boyd Roberts
2001-07-18 15:49 ` Ralph Corderoy
2001-06-29 4:30 ` Lucio De Re
1 sibling, 2 replies; 187+ messages in thread
From: George Michaelson @ 2001-06-28 23:20 UTC (permalink / raw)
To: 9fans
> We had a CS graduate come for an interview. He was clearly a bit clueless.
> The questions were scaled down to make him feel a bit better when he left.
> "What is a hexadecimal number?"
> "A combination of numbers and letters"
>
You know, there are contexts where this is the right answer. Like, if you
manipulate them as input/output objects and need to check the datastream
to see if the tokenising input should end.
And, the difference between Hex 0F and Decimal 15 is that both have exactly
the same bit-pattern in memory. Strangely, if you add 2 apples in hex
and 2 oranges in decimal OR octal, you still have 4 bits of fruit. So, you
can do mixed-base sums after all. Why don't they teach you that at
school any more?
I had a chum who'd had a 6th finger cut off early. If they'd left it on, would
he have had any advantages doing finger arithmetic?
> He had a nice suit on though.
>
Should'a employed him then. Anybody slavish enough to dress up to get a job
is probably going to work hard for the first 7 months until disallusionment
sets in.
I still writhe with embarrassment recalling an interview for the UK N.E.R.C
to get a junior progroid job onboard the antarctic ships, when asked to
write a solution to pythagoras in pascal, there, in front of the panel. Flop
sweat and memory loss and nicotine withdrawal and sheer fright combined to
make it both humiliating for me, and revealing for them. I think they made
the right decision to quietly let me go. Still, I got to see the steam loco
graveyard at barry island so it wasn't all wasted.
cheers
-George
PS I suspect that in this niche, people aren't working as a result of a
successful interview. I think they probably know people who know people
who trust people who let them on board. If there is an interview, its
more like dogs sniffing each other, or 'do you wanna be in my gang?' than
joining the army.
--
George Michaelson | APNIC
Email: ggm@apnic.net | PO Box 2131 Milton QLD 4064
Phone: +61 7 3367 0490 | Australia
Fax: +61 7 3367 0482 | http://www.apnic.net
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: the 'science' in computer science
2001-06-28 22:03 ` Matt
2001-06-28 23:20 ` George Michaelson
@ 2001-06-29 4:30 ` Lucio De Re
1 sibling, 0 replies; 187+ messages in thread
From: Lucio De Re @ 2001-06-29 4:30 UTC (permalink / raw)
To: 9fans
On Thu, Jun 28, 2001 at 11:03:57PM +0100, Matt wrote:
>
> He had a nice suit on though.
>
You don't get, it then :-) It's the shoes, what shoes was he
wearing? Were they well polished?
++L
^ permalink raw reply [flat|nested] 187+ messages in thread
[parent not found: <vikki@proweb.co.uk>]
* Re: [9fans] string to list?
@ 2001-06-10 17:32 ` vikki
2001-06-10 17:47 ` Boyd Roberts
` (2 more replies)
0 siblings, 3 replies; 187+ messages in thread
From: vikki @ 2001-06-10 17:32 UTC (permalink / raw)
To: 9fans
>rc irc client? sounds reasonable :)
>i wish i could find my 80-line C irc client i wrote last year for p9 (it
was
>my first project :).. come to think of it though, rc is a much better idea
>and a funnier one to implement :) wish i had a working p9 installation, i
>could've helped!
We're having a bit of a competition at work. They've got their monolithic
perl bot running. I'm trying to impress them with the plan9 version as a
learning exercise. I plan to have it do eval `{$msg} and do whatever it's
namespace will let it. They keep adding code to the perl bot and getting
deeper and deeper. Already they've had to split it in half (on my suggestion
:-) to separate information gathering and display.
>how about awk? daemonize an awk program if RC does not five you the
>utility to do it :)
yeah that's a good idea. I didn't fancy spawning awk for every line of irc.
I did wonder one day why plan9 has any command line utilities at all apart
from bind, mount, import, unmount , cd, echo and cat.
^ permalink raw reply [flat|nested] 187+ messages in thread
[parent not found: <matt@proweb.co.uk>]
* [9fans] help, i'm in a wet paper bag and I can't get out
@ 2001-06-12 0:39 ` Matt
2001-06-12 0:55 ` Scott Schwartz
2001-06-12 1:00 ` Boyd Roberts
0 siblings, 2 replies; 187+ messages in thread
From: Matt @ 2001-06-12 0:39 UTC (permalink / raw)
To: 9fans
Well it's not going too well.
I got this far but of course (I can say that now)
the `{..} doesn't return until $netdir/data sends an eof
and then prints each line
ifs='
'
for (k in `{ cat $netdir/data }) {
echo $k
}
so how do i read a line at a time before `{..} closes it's stdout?
once I've cracked that it's just about finished
M
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] help, i'm in a wet paper bag and I can't get out
2001-06-12 0:39 ` [9fans] help, i'm in a wet paper bag and I can't get out Matt
@ 2001-06-12 0:55 ` Scott Schwartz
2001-06-12 1:12 ` Boyd Roberts
2001-06-12 1:00 ` Boyd Roberts
1 sibling, 1 reply; 187+ messages in thread
From: Scott Schwartz @ 2001-06-12 0:55 UTC (permalink / raw)
To: 9fans
| I got this far but of course (I can say that now)
| the `{..} doesn't return until $netdir/data sends an eof
| and then prints each line
Instead of "for cat", don't you want "while read"?
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] help, i'm in a wet paper bag and I can't get out
2001-06-12 0:39 ` [9fans] help, i'm in a wet paper bag and I can't get out Matt
2001-06-12 0:55 ` Scott Schwartz
@ 2001-06-12 1:00 ` Boyd Roberts
2001-06-12 1:30 ` Jonathan Sergent
2001-06-15 8:27 ` Hermann Samso
1 sibling, 2 replies; 187+ messages in thread
From: Boyd Roberts @ 2001-06-12 1:00 UTC (permalink / raw)
To: 9fans
> I got this far but of course (I can say that now)
> the `{..} doesn't return until $netdir/data sends an eof
> and then prints each line
well, obviously. it's a file isn't it? <smirk>
> so how do i read a line at a time before `{..} closes it's stdout?
write some C program that that reads _unbuffered_ characters
and spits them until it sees 'end of line' (whatever that may be).
you should buffer the output, but _not_ the input.
can't be more than 20 lines of code.
btw: i hope you're dealing with 8 bit chars 'cos latin-1 will
really screw up utf encoded streams that the rest of the
system expects. years ago i wrote (on ultrix) riso [rune
to iso-latin-1] and isor (pronounced eye-sore) filters
so that the unix sam could deal with the few french docs
i had to deal with.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] help, i'm in a wet paper bag and I can't get out
2001-06-12 1:00 ` Boyd Roberts
@ 2001-06-12 1:30 ` Jonathan Sergent
2001-06-15 8:27 ` Hermann Samso
1 sibling, 0 replies; 187+ messages in thread
From: Jonathan Sergent @ 2001-06-12 1:30 UTC (permalink / raw)
To: 9fans
On Monday, June 11, 2001, at 06:00 PM, Boyd Roberts wrote:
> write some C program that that reads _unbuffered_ characters
> and spits them until it sees 'end of line' (whatever that may be).
> you should buffer the output, but _not_ the input.
You could just read the manual and use /bin/read, instead of rewriting
it.
So you get
{
while () {
line=`{read}
echo line: $line
}
} < filename
Somehow putting the < filename after the inner } makes rc reopen it for
each loop iteration. (Am I misinterpreting this?)
A more convoluted way to do to the same thing would be
{ echo 0 > /srv/something.$pid } < filename
while () {
line=`{read /srv/something.$pid}
echo line: $line
}
rm /srv/something.$pid
but that's probably better for showing off /srv to your friends than it
is for actually solving the problem.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] help, i'm in a wet paper bag and I can't get out
2001-06-12 1:00 ` Boyd Roberts
2001-06-12 1:30 ` Jonathan Sergent
@ 2001-06-15 8:27 ` Hermann Samso
2001-06-15 11:53 ` Boyd Roberts
1 sibling, 1 reply; 187+ messages in thread
From: Hermann Samso @ 2001-06-15 8:27 UTC (permalink / raw)
To: 9fans
Boyd Roberts <boyd@fr.inter.net> wrote:
>> I got this far but of course (I can say that now)
>> the `{..} doesn't return until $netdir/data sends an eof
>> and then prints each line
> well, obviously. it's a file isn't it? <smirk>
>> so how do i read a line at a time before `{..} closes it's stdout?
> write some C program that that reads _unbuffered_ characters
> and spits them until it sees 'end of line' (whatever that may be).
> you should buffer the output, but _not_ the input.
> can't be more than 20 lines of code.
> btw: i hope you're dealing with 8 bit chars 'cos latin-1 will
> really screw up utf encoded streams that the rest of the
> system expects. years ago i wrote (on ultrix) riso [rune
> to iso-latin-1] and isor (pronounced eye-sore) filters
> so that the unix sam could deal with the few french docs
> i had to deal with.
With so many snippets of code, everyone could make use
of, isn't there any common repository? Or will they
allget integrated in time for next release?
Ok, there is always Deja News, but...
saludos,
hermann samso
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] help, i'm in a wet paper bag and I can't get out
2001-06-15 8:27 ` Hermann Samso
@ 2001-06-15 11:53 ` Boyd Roberts
2001-06-15 12:18 ` Matt
2001-06-15 14:01 ` Matt
0 siblings, 2 replies; 187+ messages in thread
From: Boyd Roberts @ 2001-06-15 11:53 UTC (permalink / raw)
To: 9fans
From: "Hermann Samso" <samso@studserv.stud.uni-hannover.de>
> With so many snippets of code, everyone could make use
> of, isn't there any common repository? Or will they
> allget integrated in time for next release?
> Ok, there is always Deja News, but...
oh, but there is. you must have missed the 'why don't
we build a common repository' thread. i finally cracked
(in desperation) and did this:
http://mapage.noos.fr/~repo
but about the only thing it's done is to a) proove a
point and b) receive mail of the form 'nice page.
the first cut was done by hand, the second is automated
with a mash-mk mashfile on inferno.
the bitsy code should probably go back to 1127.
i don't mind adding it too.
matt's rc irc bot could be added if he so wishes.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] help, i'm in a wet paper bag and I can't get out
2001-06-15 11:53 ` Boyd Roberts
@ 2001-06-15 12:18 ` Matt
2001-06-15 14:01 ` Matt
1 sibling, 0 replies; 187+ messages in thread
From: Matt @ 2001-06-15 12:18 UTC (permalink / raw)
To: 9fans
----- Original Message -----
From: "Boyd Roberts" <boyd@fr.inter.net>
To: <9fans@cse.psu.edu>
Sent: Friday, June 15, 2001 12:53 PM
Subject: Re: [9fans] help, i'm in a wet paper bag and I can't get out
> From: "Hermann Samso" <samso@studserv.stud.uni-hannover.de>
> > With so many snippets of code, everyone could make use
> > of, isn't there any common repository? Or will they
> > allget integrated in time for next release?
> > Ok, there is always Deja News, but...
>
> oh, but there is. you must have missed the 'why don't
> we build a common repository' thread. i finally cracked
> (in desperation) and did this:
>
> http://mapage.noos.fr/~repo
>
> but about the only thing it's done is to a) proove a
> point and b) receive mail of the form 'nice page.
>
> the first cut was done by hand, the second is automated
> with a mash-mk mashfile on inferno.
>
> the bitsy code should probably go back to 1127.
> i don't mind adding it too.
>
> matt's rc irc bot could be added if he so wishes.
>
>
>
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] help, i'm in a wet paper bag and I can't get out
2001-06-15 11:53 ` Boyd Roberts
2001-06-15 12:18 ` Matt
@ 2001-06-15 14:01 ` Matt
2001-06-15 14:25 ` Boyd Roberts
1 sibling, 1 reply; 187+ messages in thread
From: Matt @ 2001-06-15 14:01 UTC (permalink / raw)
To: 9fans
bugger, sorry
>but about the only thing it's done is to a) proove a
>point and b) receive mail of the form 'nice page.
no news is good news?
>matt's rc irc bot could be added if he so wishes
A basic irc bot that evals commands it's given with
the permission & namespace of whoever started it.
http://www.proweb.co.uk/~matt/chugly.rc
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] help, i'm in a wet paper bag and I can't get out
2001-06-15 14:01 ` Matt
@ 2001-06-15 14:25 ` Boyd Roberts
0 siblings, 0 replies; 187+ messages in thread
From: Boyd Roberts @ 2001-06-15 14:25 UTC (permalink / raw)
To: 9fans
> no news is good news?
well, it's better than being the middle of a firefight...
err, flamewar.
> A basic irc bot that evals commands it's given with
> the permission & namespace of whoever started it.
> http://www.proweb.co.uk/~matt/chugly.rc
ok, will do.
i got it down to this as a mashfile:
for (i in contrib/*)
contrib.html : $i/li.html;
*/*/li.html :~ $1/$2/url { mash tools/c2li $1/$2 > $0 };
*/*/url :~ $1/$2/desc {};
*/*/desc :~ $1/$2/from {};
*/*/from :~ $1/$2/date {};
*.html :~ $1/0/url { cat $1/*/li.html > $0 };
default: index.html {};
index.html : head.html contrib.html tail.html { cat head.html contrib.html tail.html > index.html };
----
the contrib directory has directories, named 0...n, which have these files:
url
desc [description]
from
date [rfc822/std11 date. it's well known and can be parsed]
li.html [this is the html <li> made out of the above files]
brucee gave me a bit of a hand, 'cos mash-mk is not mk or make.
i think he has a much better and simpler solution to the problem.
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] bitsy question
@ 2001-06-26 16:33 John Packer
2001-06-26 17:10 ` [9fans] " Dan Cross
0 siblings, 1 reply; 187+ messages in thread
From: John Packer @ 2001-06-26 16:33 UTC (permalink / raw)
To: 9fans
I have Plan9 installed on my ipaq, but I don't have a pcmcia sleeve,
or wavelan on my network.
So I have been trying to link the bitsy to my terminal using ppp over
the
serial port. (I made a ramdisk with ip/ppp).
PPP tries to authenticate for 30 seconds (through chap, I think) then
times out.
I've tried running ppp a few different ways, but something like
ip/ppp -df -b 115200 -p /dev/eia0 -s $user:$secret 135.104.99.5
on the bitsy and something like
ip/ppp -dfS -b 115200 -p /dev/eia0 135.104.99.1
on the server.
Has anyone tried this? What am I doing wrong?
Thanks,
John
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] Re: bitsy question
2001-06-26 16:33 [9fans] bitsy question John Packer
@ 2001-06-26 17:10 ` Dan Cross
2001-06-26 19:51 ` John Packer
` (2 more replies)
0 siblings, 3 replies; 187+ messages in thread
From: Dan Cross @ 2001-06-26 17:10 UTC (permalink / raw)
To: packer; +Cc: 9fans
In article <3B38BA06.E55B62AC@bway.net> you write:
>I have Plan9 installed on my ipaq, but I don't have a pcmcia sleeve,
>or wavelan on my network.
Ouch; that makes it much more difficult to use, as you have discovered.
>So I have been trying to link the bitsy to my terminal using ppp over
>the serial port. (I made a ramdisk with ip/ppp).
>
>PPP tries to authenticate for 30 seconds (through chap, I think) then
>times out.
>
>I've tried running ppp a few different ways, but something like
>
> ip/ppp -df -b 115200 -p /dev/eia0 -s $user:$secret 135.104.99.5
>
>on the bitsy and something like
>
> ip/ppp -dfS -b 115200 -p /dev/eia0 135.104.99.1
>
>on the server.
>
>Has anyone tried this? What am I doing wrong?
Well, at least one thing that you're probably encountering is that the
bitsy tries to use the serial port as a console device, and is
hardwired in the kernel to do so. In order to fix that, you have to
edit the kernel sources in /sys/src/9/bitsy/ and recompile; I managed
to turn it off by changing the argument to sa1110_uartsetup() to zero
in main.c. However, if you do ONLY that, the machine panics when it
comes up because the keyboard input queue for the console device is
nil. Whoops! You have to change sa1110_uartsetup() in sa1110uart.c
(the last routine in the file) to assign a valid Queue pointer to
kbdq. I just changed the relevant section to be:
if(console) {
uartspecial(p, 115200, &kbdq, &printq, kbdcr2nl);
} else {
kbdq = qopen(4*1024, 0, 0, 0);
}
That is, adding the ``else'' clause which calls qopen. I'm not sure
that this is the best method; if there's a better one, I'd be
interested to know.
btw- the serial console mode can be really handy at times; it's nice to
be able to put the bitsy on it's cradle, start up con, and then type
into bitsy windows without using bitsy/keyboard. The hand becomes much
less cramped.
Anyway, I'm assuming this is something you haven't messed with yet;
it'd most definately mess with ip/ppp, since every other character gets
redirected to /dev/cons!
Another problem you may have is that the bitsy uart driver doesn't
really do modem control; actually, it might be more accurate to say
that the StrongARM SA1100 doesn't do modem control signaling directly.
Instead, it simulates it using the GPIO pins on the 1100. I'm not sure
what exactly, if anything, the bitsy does differently in this regard
(the driver has a comment about the RTS/CTS stuff being h3600 specific,
but nothing more); my attempts to add DTR and RTS/CTS modem control to
the serial driver didn't work the way I had expected them to (I was
trying to hack them in in order to get my Targus stowaway keyboard
working; I did get it to mostly ``do the right thing,'' but it wasn't
perfect and I got busy with other stuff. I'll get back to it
eventually.)
I've been meaning to try out ppp on the bitsy, using my ricochet modem,
but I haven't round a serial cable for it yet (well, I haven't exactly
been looking that hard). I definately thing it'd be pretty cool to use
my bitsy to send email from the train.
bway.net, huh? You in New York? Anyone else on the list in NYC? We
ought to start a New York Plan 9 Club or something.
- Dan C.
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] Re: bitsy question
2001-06-26 17:10 ` [9fans] " Dan Cross
@ 2001-06-26 19:51 ` John Packer
2001-06-26 20:34 ` Dan Cross
2001-06-27 1:15 ` [9fans] Two cpu servers? Ish Rattan
2001-06-26 20:09 ` [9fans] Re: bitsy question John Packer
2001-06-26 20:18 ` Latchesar Ionkov
2 siblings, 2 replies; 187+ messages in thread
From: John Packer @ 2001-06-26 19:51 UTC (permalink / raw)
To: Dan Cross, 9fans
Dan Cross wrote:
> You have to change sa1110_uartsetup() in sa1110uart.c
> (the last routine in the file) to assign a valid Queue pointer to
> kbdq. I just changed the relevant section to be:
>
> if(console) {
> uartspecial(p, 115200, &kbdq, &printq, kbdcr2nl);
> } else {
> kbdq = qopen(4*1024, 0, 0, 0);
> }
>
This is an interesting clue. I'll try this out tonight.
> btw- the serial console mode can be really handy at times; it's nice to
> be able to put the bitsy on it's cradle, start up con, and then type
> into bitsy windows without using bitsy/keyboard.
I've noticed this - very useful.
> Another problem you may have is that the bitsy uart driver doesn't
> really do modem control
I don't think I need modem control, I'm not using a modem: just a
PPP server and client over the serial cable to my PC.
This is, I'm guessing, how ActiveSync works, and how Linux users connect
to their Ipaqs.
It just doesn't seem to authenticate.
This may be the wrong approach, I don't know.
> I've been meaning to try out ppp on the bitsy, using my ricochet modem,
> but I haven't round a serial cable for it yet (well, I haven't exactly
> been looking that hard). I definately thing it'd be pretty cool to use
> my bitsy to send email from the train.
Very.
>
> bway.net, huh? You in New York? Anyone else on the list in NYC? We
> ought to start a New York Plan 9 Club or something.
Yep.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: bitsy question
2001-06-26 19:51 ` John Packer
@ 2001-06-26 20:34 ` Dan Cross
2001-06-29 22:32 ` Boyd Roberts
2001-06-27 1:15 ` [9fans] Two cpu servers? Ish Rattan
1 sibling, 1 reply; 187+ messages in thread
From: Dan Cross @ 2001-06-26 20:34 UTC (permalink / raw)
To: 9fans; +Cc: packer
In article <3B38E7BE.D4C22541@bway.net> you write:
>
> [...]
>
>> Another problem you may have is that the bitsy uart driver doesn't
>> really do modem control
>
>I don't think I need modem control, I'm not using a modem: just a
>PPP server and client over the serial cable to my PC.
Oh duh; of course you said that earlier and I was too slow to catch
on. Yes, you're right; if you're not using a modem, you don't need
modem control. For that matter, you might not need modem control
even if you have a modem.
>This is, I'm guessing, how ActiveSync works, and how Linux users connect
>to their Ipaqs.
Well, I think they mostly use ``normal'' serial line protocols; either
just raw text passed over the serial line, or using a data transfer
protocol like xmodem. I'm not sure they'd bother with the overhead of
PPP in the general case (where they just wanted to sync data, or copy
a file; for making TCP connections and the like, yeah, you'd need PPP
or SLIP or a real network interface).
>It just doesn't seem to authenticate.
That's almost certainly the keyboard input queue messing you up.
>This may be the wrong approach, I don't know.
Well, if you've got an extra thousand bucks just laying around, definately
invest in the Wavelan route. If not, then it's a reasonable approach; it
won't zoom, though, and I've found ip/ppp pretty unreliable (using a wireless
modem, though; still, it seems to work reasonably well under FreeBSD. I
haven't been motivated enough to track down what's wrong, though).
> [...]
>
>> bway.net, huh? You in New York? Anyone else on the list in NYC? We
>> ought to start a New York Plan 9 Club or something.
>
>Yep.
Cool. Any other New Yorker's?
- Dan C.
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] Two cpu servers?
2001-06-26 19:51 ` John Packer
2001-06-26 20:34 ` Dan Cross
@ 2001-06-27 1:15 ` Ish Rattan
1 sibling, 0 replies; 187+ messages in thread
From: Ish Rattan @ 2001-06-27 1:15 UTC (permalink / raw)
To: 9fans
Does it make sense to have two cpu-servers?
I have a standalone spu/auth server running. How can I add another cpu
server to have two of these?
Any pointers will be appreciated.
-ishwar
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] Re: bitsy question
2001-06-26 17:10 ` [9fans] " Dan Cross
2001-06-26 19:51 ` John Packer
@ 2001-06-26 20:09 ` John Packer
2001-06-26 20:36 ` Dan Cross
2001-06-26 20:18 ` Latchesar Ionkov
2 siblings, 1 reply; 187+ messages in thread
From: John Packer @ 2001-06-26 20:09 UTC (permalink / raw)
To: 9fans
> Do you also use that serial line as the console? You'll get garbage
> in your packets that way.
>
> Sape
Hmm. I'm not running a con window when I try this.
The debugging output appears to indicate a lack of response to a CHAP
request.
Maybe it is not picking up the '-s $user:$secret' option from the client.
John
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Re: bitsy question
2001-06-26 17:10 ` [9fans] " Dan Cross
2001-06-26 19:51 ` John Packer
2001-06-26 20:09 ` [9fans] Re: bitsy question John Packer
@ 2001-06-26 20:18 ` Latchesar Ionkov
2001-06-26 20:28 ` Matt
2 siblings, 1 reply; 187+ messages in thread
From: Latchesar Ionkov @ 2001-06-26 20:18 UTC (permalink / raw)
To: 9fans
On Tue, Jun 26, 2001 at 01:10:45PM -0400, Dan Cross said:
>
> bway.net, huh? You in New York? Anyone else on the list in NYC? We
> ought to start a New York Plan 9 Club or something.
I am in New York too.
Lucho
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] architectures
@ 2001-07-12 8:42 forsyth
2001-07-12 13:56 ` Laura Creighton
2001-07-12 16:13 ` Ozan Yigit
0 siblings, 2 replies; 187+ messages in thread
From: forsyth @ 2001-07-12 8:42 UTC (permalink / raw)
To: 9fans
>>i'm particularly fond of the acme interface, and i really
>>like the chording (okay, maybe it's not for everyone, but _i_
>>really like it). i'm asking about non-techie folks. for them,
>>wouldn't a single-button interface be simpler to understand?
not necessarily, since the functionality of the extra buttons
must be provided somehow, whether by menus, pop-up menus,
key-mouse combinations, keys alone, or some other way. much might
depend on the choice of conventions for using more than one button.
that in acme all three buttons select text is a big simplification.
i usually introduce it as follows: ``button 1 selects text, button 2
selects text, and button 3 ...'' and during the following pause
nearly everyone says ``selects text?''. i then explain
that `of course' each button does different things with
the text selected. that seems fine. the chording for cut/paste/copy
takes a little practice, but since it has a `feel' much like grabbing
text from the screen, that also seems fine. outside acme,
the Blit convention (perhaps adopted from Smalltalk, i don't know)
was something like: button 1 generally selected things, button 2 provided local
operations (usually on the thing selected), and button 3 provided global operations
for the application, with a few exceptions such as paint programs.
most menus were kept fairly small.
i know at least one non- technical user of acme who sends and receives
mail, plumbing photos and other things, and editing quite happily.
other non-technical people i've shown it to wanted to use acme on
their machines for document preparation and email because the
organisation into columns and frames and the use of the buttons was
just so much more effective than their `desktop' or a clutter of
windows. (they also like the soft use of colour.)
contrary to Tog's advice on this point: with care i suspect
you can make abstractions simple and effective enough without insisting on
drawing a tenuous likeness to something in the `real world'.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] architectures
2001-07-12 8:42 [9fans] architectures forsyth
@ 2001-07-12 13:56 ` Laura Creighton
2001-07-12 16:13 ` Ozan Yigit
1 sibling, 0 replies; 187+ messages in thread
From: Laura Creighton @ 2001-07-12 13:56 UTC (permalink / raw)
To: 9fans; +Cc: lac
re: drawing tenuous likenesses to the real world.
It is possible in the days before everybody knew what a computer was,
and a computer program was, that there was some value in giving a user
a metaphor with something else on the real world. These days it is a
major problem because quite frequently the metaphor is lousier than
what we could write if we focused on _how efficiently can we do what
we want to do_ rather than _what is something, anything, that somebody
is likely to have done before which is sort of like what we want to do_.
My favourite example is the desktop metaphor. Now neat people can
have the experience of a messed up and cluttered desk. You too can
lose important work and documents because you can't find them!
Laura
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] architectures
2001-07-12 8:42 [9fans] architectures forsyth
2001-07-12 13:56 ` Laura Creighton
@ 2001-07-12 16:13 ` Ozan Yigit
2001-07-12 16:33 ` Matt
1 sibling, 1 reply; 187+ messages in thread
From: Ozan Yigit @ 2001-07-12 16:13 UTC (permalink / raw)
To: 9fans
forsyth@caldo.demon.co.uk writes:
> contrary to Tog's advice on this point: with care i suspect
> you can make abstractions simple and effective enough without insisting on
> drawing a tenuous likeness to something in the `real world'.
An interesting related bit of work is "The Anti-Mac Interface" by Don
Gentner and Jakob Nielson, Communications of the ACM, 29(8), pp. 70-82
August 1996, but also found online. i wish we could have more of this kind
of de/re-construction; attempting to break all the interface design rules
and see what comes out. the results of this particular attempt are more
along the lines of raisin-bran cereal than waldorf salad but thought
provoking nevertheless.
oz
--
www.cs.yorku.ca/~oz | if you couldn't find any weirdness, maybe
york u. computer science | we'll just have to make some! -- hobbes
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] architectures
2001-07-12 16:13 ` Ozan Yigit
@ 2001-07-12 16:33 ` Matt
2001-07-12 18:12 ` Scott Schwartz
0 siblings, 1 reply; 187+ messages in thread
From: Matt @ 2001-07-12 16:33 UTC (permalink / raw)
To: 9fans
> An interesting related bit of work is "The Anti-Mac Interface" by Don
> Gentner and Jakob Nielson, Communications of the ACM, 29(8), pp. 70-82
> August 1996, but also found online.
http://www.acm.org/cacm/AUG96/antimac.htm
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] architectures
2001-07-12 16:33 ` Matt
@ 2001-07-12 18:12 ` Scott Schwartz
2001-07-12 18:16 ` Martin Harriss
2001-07-12 18:43 ` Dan Cross
0 siblings, 2 replies; 187+ messages in thread
From: Scott Schwartz @ 2001-07-12 18:12 UTC (permalink / raw)
To: 9fans
> http://www.acm.org/cacm/AUG96/antimac.htm
``...in designing Sun's home page we decided we needed to change it drastically
every month to keep the users' interest...''
No wonder it's so totally impossible to find anything in there! That one
statement makes me doubt every other thing they said. Sun's web site
has to be the worst I've ever used, especially taking into account
the obviously huge amount of effort that goes into it. It's clearly
all about entertaining suits, and not at all about making information
available to users who don't want to waste their time.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] architectures
2001-07-12 18:12 ` Scott Schwartz
@ 2001-07-12 18:16 ` Martin Harriss
2001-07-12 18:43 ` Dan Cross
1 sibling, 0 replies; 187+ messages in thread
From: Martin Harriss @ 2001-07-12 18:16 UTC (permalink / raw)
To: 9fans
Scott Schwartz wrote:
>
> > http://www.acm.org/cacm/AUG96/antimac.htm
>
> ``...in designing Sun's home page we decided we needed to change it drastically
> every month to keep the users' interest...''
>
> No wonder it's so totally impossible to find anything in there! That one
> statement makes me doubt every other thing they said. Sun's web site
> has to be the worst I've ever used, especially taking into account
> the obviously huge amount of effort that goes into it. It's clearly
> all about entertaining suits, and not at all about making information
> available to users who don't want to waste their time.
It's also one of the slowest web sites around. I hate to think of the
amount of time that I've had to wait wating for their pages to load.
They used to *boast* that their web services were provided by a pair of
Ultra 1's. Looks like they still are.
</gripe>
Martin
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] architectures
2001-07-12 18:12 ` Scott Schwartz
2001-07-12 18:16 ` Martin Harriss
@ 2001-07-12 18:43 ` Dan Cross
2001-07-13 14:52 ` Douglas A. Gwyn
1 sibling, 1 reply; 187+ messages in thread
From: Dan Cross @ 2001-07-12 18:43 UTC (permalink / raw)
To: 9fans
In article <20010712181225.17835.qmail@g.bio.cse.psu.edu> you write:
>``...in designing Sun's home page we decided we needed to change it drastically
>every month to keep the users' interest...''
Hmm, I predict that Sun will be the DEC of the 2000's; they'll stick
to an obsolete and overburdened product line until it's too late, and
then get bought out by Dell and ultimately squashed under foot.
- Dan ``I saw a Solarian Light'' C.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Virtual memory in BSD and Plan9
@ 2001-10-25 17:55 Russ Cox
2001-10-25 18:29 ` William Josephson
0 siblings, 1 reply; 187+ messages in thread
From: Russ Cox @ 2001-10-25 17:55 UTC (permalink / raw)
To: 9fans
Could you please recommend me a reading on both architectures to
understand differences between them. I read here that BSD paging has
some drawbacks to AT&T one (used in Plan9). And I want to make this
clear for myself.
The discussions here were talking about many-years-old
systems. I don't think anyone even mentioned Plan 9's VM system,
which is just about the simplest thing you could imagine.
The BSDs have oodles more ``features.'' I'd look in
www.researchindex.com for the latest stuff, and in McKusick et al.
(Design and Implementation of the 4.4BSD OS) for older stuff.
You can decide for yourself whether Plan 9 needs any of it.
Russ
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Virtual memory in BSD and Plan9
2001-10-25 17:55 [9fans] Virtual memory in BSD and Plan9 Russ Cox
@ 2001-10-25 18:29 ` William Josephson
2001-10-26 8:09 ` [9fans] acme bug/annoyance? Matt
2001-10-29 10:16 ` [9fans] Virtual memory in BSD and Plan9 John S. Dyson
0 siblings, 2 replies; 187+ messages in thread
From: William Josephson @ 2001-10-25 18:29 UTC (permalink / raw)
To: 9fans
On Thu, Oct 25, 2001 at 01:55:25PM -0400, Russ Cox wrote:
> The discussions here were talking about many-years-old
> systems. I don't think anyone even mentioned Plan 9's VM system,
> which is just about the simplest thing you could imagine.
> The BSDs have oodles more ``features.'' I'd look in
> www.researchindex.com for the latest stuff, and in McKusick et al.
> (Design and Implementation of the 4.4BSD OS) for older stuff.
> You can decide for yourself whether Plan 9 needs any of it.
You probably want to take a look at Charles Cranor's PHd thesis from
Washington on UVM. If I recall correctly, some of the *BSDs (NetBSD,
FreeBSD?) have picked it up or at least borrowed ideas.
-WJ
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] acme bug/annoyance?
2001-10-25 18:29 ` William Josephson
@ 2001-10-26 8:09 ` Matt
2001-10-26 11:36 ` rob pike
2001-10-29 10:16 ` [9fans] Virtual memory in BSD and Plan9 John S. Dyson
1 sibling, 1 reply; 187+ messages in thread
From: Matt @ 2001-10-26 8:09 UTC (permalink / raw)
To: 9fans
Hi,
I just started a new instance of Acme
typed some code in an empty yellow window which was a directory
listing of an empty directory, I'd put the filename in the titlebar
but not saved the file.
All was going well until I resized the column and lost all my typing.
Not the end of the world but not very user friendly either.
An instance of where DWIM would win over "you have to have the text in
a file already, stupid"
Matt
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] acme bug/annoyance?
2001-10-26 8:09 ` [9fans] acme bug/annoyance? Matt
@ 2001-10-26 11:36 ` rob pike
2001-10-26 14:43 ` Scott Schwartz
0 siblings, 1 reply; 187+ messages in thread
From: rob pike @ 2001-10-26 11:36 UTC (permalink / raw)
To: 9fans
A nasty problem here. When you resize a directory window, acme should recolumnate
the output, but I couldn't see how to get that right while keeping the user's text, so I
just started over. A directory window is therefore a kind of scratch typing space, which
is actually a feature I like but is clearly a consequence of, rather than integral to, the design.
I suppose the documentation should mention this.
-rob
----- Original Message -----
From: Matt <matt@proweb.co.uk>
To: <9fans@cse.psu.edu>
Sent: Friday, October 26, 2001 4:09 AM
Subject: [9fans] acme bug/annoyance?
> Hi,
>
> I just started a new instance of Acme
>
> typed some code in an empty yellow window which was a directory
> listing of an empty directory, I'd put the filename in the titlebar
> but not saved the file.
>
> All was going well until I resized the column and lost all my typing.
>
> Not the end of the world but not very user friendly either.
>
> An instance of where DWIM would win over "you have to have the text in
> a file already, stupid"
>
> Matt
>
>
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Virtual memory in BSD and Plan9
2001-10-25 18:29 ` William Josephson
2001-10-26 8:09 ` [9fans] acme bug/annoyance? Matt
@ 2001-10-29 10:16 ` John S. Dyson
1 sibling, 0 replies; 187+ messages in thread
From: John S. Dyson @ 2001-10-29 10:16 UTC (permalink / raw)
To: 9fans
wkj-despam@eecs.harvard.edu (William Josephson) wrote in message news:<20011025142927.B8085@honk.eecs.harvard.edu>...
> On Thu, Oct 25, 2001 at 01:55:25PM -0400, Russ Cox wrote:
> > The discussions here were talking about many-years-old
> > systems. I don't think anyone even mentioned Plan 9's VM system,
> > which is just about the simplest thing you could imagine.
> > The BSDs have oodles more ``features.'' I'd look in
> > www.researchindex.com for the latest stuff, and in McKusick et al.
> > (Design and Implementation of the 4.4BSD OS) for older stuff.
> > You can decide for yourself whether Plan 9 needs any of it.
>
> You probably want to take a look at Charles Cranor's PHd thesis from
> Washington on UVM. If I recall correctly, some of the *BSDs (NetBSD,
> FreeBSD?) have picked it up or at least borrowed ideas.
>
FreeBSD and NetBSD have different VM systems. FreeBSD's (which I
am the primary implementer), is really a corrected and filled out
MACH VM for UNIX. It provides lots of the necessary shortcuts
fully virtualized for the process VM forking and things like that.
The original MACH VM port really wasn't meant as being production
ready (per my discussions with Hibler), but was more of a feasibility
exercise. Even though it wasn't fully made robust in the original
implementations, it wasn't that much worse than many commercial UNIX
VM behaviors.
Probably the biggest difference doesn't occur during 'normal'
memory resident situations, but where FreeBSD has rather advanced
paging stats, and really does put off the thrashfest until the
system doesn't have enough pages to supply an adequate resident
working set. If there is minimally enough memory, FreeBSD will
converge reasonably quickly, without undue thrashing. In my early
experiments, it was very satisfying to hear the system 'calm down'
after experiencing thrashing due to a necessary change in working
set population. Most other systems tended to keep on thrashing
for long periods, even when there was obviously enough memory. The
pseudo-random pagouts and invalidations from non-FreeBSD systems
tended to really screw up the page reference information on memory
segments being used by otherwise runnable processes. The relatively
good behavior has been especially useful when running user-mode
windowing systems, where the blocking from poorly chosen page
invalidations can really stop-up the works.
Both FreeBSD's VM and NetBSD's VM work pretty well (no real complaints
from either party), and most/all of the limitations of the original
MACH VM have been expunged. There were even cases of limitations
that I thought to be unsolvable in the FreeBSD code eventually simply
be an 'exercise in data structures', and the last REAL limitation
due to address space/fork inheritance was remedied as a result of
competition from NetBSD's new VM stuff.
FreeBSDs and NetBSDs code is both adequately portable, and that
should not be a deciding issue. Frankly, the most important deciding
issue is probably based upon knowledge of the VM code that the
individual who might do the port to Plan 9. One might make a
'decision' that the VM shouldn't page anyway (except in odd situations),
and so the relative advantages of the two systems becomes less
important.
My philosophy is based upon the fact that an OS MUST NOT just be a fair
weather friend, and from my rather VM-centered viewpoint, I believe that
this includes the fact that VM shouldn't randomly thrash, when it could
more actively converge to a reasonable working set (when possible.)
If starting from scratch, it is really easy to write some code that
works. However, there is ALOT more work to making a VM system
function under load to maximize availability of CPU cycles. Unfortunately,
it is clear that VM system behavior is almost always a secondary
priority, because it doesn't specify/benchmark very easily.
John
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] Getting started in Plan9 - help
@ 2002-01-20 20:02 Roshan James
2002-01-20 21:01 ` Matt H
` (3 more replies)
0 siblings, 4 replies; 187+ messages in thread
From: Roshan James @ 2002-01-20 20:02 UTC (permalink / raw)
To: 9fans
[-- Attachment #1: Type: text/plain, Size: 3665 bytes --]
Getting started in Plan9
-------------------------
Its been a little over a week since i got my Plan9 working and
I still seem to be in tourist mode.Lots of questions and
a few suggestions:
(I promise I have tried to answer these for myself before
before I am ask them)
It would be great if we have a school boy style step-by-step
getting-off-the-ground tour of plan9, maybe somewhere in the
wiki. I would be glad to do this, if i knew enough.
Graphics
-----------
- I am working with an S3 Trio 64v2 card, the install floppy
gave me 800*600 res,but after installation i am on 640*480 and
i cant seem to be able to change it
aux/vga -l 800x600x8
gives me
'Warning (BUG) : redefinition of aperture does not change
s3screen segment.'
in a black background in the sentre of the screen and an error
message that reads
'aux/vga: vgactlw: <size 800x600x8 m8>: vga already configured'
in the console window. it is a low end card but I believe that
I did have a higher res through the boot disk so it should be
possible here too. how can i change to a higher res ?
- If plan9 is booted through xosl in 640*480 res,plan9 graphics
display ends up corrupt. the bootloader does switch to text mode
before the OS is booted. anyother resolution or a text mode boot
loader does not seem to have a problem.
The right quarter of the screen (approx) seems to be a duplicate
of the band of the screen display between in the left part. (bad
description i know). Anyway to fix this ?
Acessibility
-------------
- How can I read a couple of html docs in Plan9 ?
- Is there a place where the uses of directories the std file system
heirarchy is discussed, esp /n ?
- /n/c: exists, how can i access the extended partitions ?
- How can i access the floppy a: ? /n/a: exists but shows no files.
- How can i access the extended windows partitions ?
- Problem with accessing C: File operations to /n/c: causes a problem
'%mkdir /n/c:/testdir'
'mkdir: cant create /n/c:/testdir: write to hungup channel'
also a black background error message comes (is there a generic name
for these messages ?)
'dossrv 45: suicide: sys: trap fault read addr=0xb pc=0x00004757'
help ?
Shell
------
- How can I find/search for a file in Plan9 ? the usual find /|grep xxx
does not exist here, what is the equivalent ?
- Why doesnt/Can rc have autocomplete and filename completion as in
bash ? This has become so neccessary.
Keys
-----
- Why cant the left/right arrow keys+home+end keys move the cursor,
it is really difficult to edit something by placing the cursor there
with the mouse.
- Unless is it part of a grander plan (no pun intended), can we move
the process interrupt key from Del to something else and have the
conventional functionality of del back ?
General
-------
- Is the option of plan9 default boot in bootsetup (during install)
safe for other OSes that exist on the system ?
- Why arent there more applications and more developers interested
in developing for plan9 ?
Russ, I think it would kill you to keep answering all the newbie
questions. Russ, Imel, Thanks for all the help you have been. I
think the Plan9 faq needs updation with some of the more generic
questions here. This is a lesson that could learned from the Win32's,
if you want the OS to grow, you have to get people comfortable with
it very fast. I think we can make that happen.
Rosh.
-------------------------------------------------------------------------------------
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them.
(Lord of the Rings)
[-- Attachment #2: Type: text/html, Size: 4834 bytes --]
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Getting started in Plan9 - help
2002-01-20 20:02 [9fans] Getting started in Plan9 - help Roshan James
@ 2002-01-20 21:01 ` Matt H
2002-01-20 22:02 ` Scott Schwartz
2002-01-21 10:22 ` Boyd Roberts
2002-01-20 21:03 ` William S.
` (2 subsequent siblings)
3 siblings, 2 replies; 187+ messages in thread
From: Matt H @ 2002-01-20 21:01 UTC (permalink / raw)
To: 9fans
Hi,
here's my set of slightly flippant answers
> - How can I read a couple of html docs in Plan9 ?
install inferno and use the netscape 3 hybrid Charon
I bet you can't wait :)
Web browsing it's plan9's end user pitfall.
No browser, not even text only (unless you count downloading & stripping the html tags text only)
> - How can I find/search for a file in Plan9 ? the usual find /|grep xxx
> does not exist here, what is the equivalent ?
du I think is your best bet
it's better still to learn where everything is :)
luckily there aren't 5 different directories where programs hide (well there can be but...)
all the executables show themselves in /bin which is a union of the directories where executables live if you see what I mean. There's aren't that many, have a look through them all, you'll remember easily enough.
> - Why doesnt/Can rc have autocomplete and filename completion as in
> bash ? This has become so neccessary.
yes, well, you see plan9 is more mouse driven. eventually you'll probably end up with Acme as much your "shell" as anything, and you'll find auto complete is unneccessary.
But you're right, it is a nice feature of the bash shell but then there are soooo many goddam directories on a Linux/FreeBSD box and auto complete is Bash's way of trying to alleviate the pain. If you miss it too much I'm sure you could just write a shell script to monitor /dev/cons for tabs, and echo the stuff into /dev/cons.
Personally, I do prefer having the screen as free form is plan9's is. The shell is more than the commands you can type, it's where you can type them.
> - Why cant the left/right arrow keys+home+end keys move the cursor,
> it is really difficult to edit something by placing the cursor there
> with the mouse.
That's what I said and I still get the urge to say it out loud. They told me I'd get used to it and you know what, I haven't. I'd even settle for Ctrl-J. But when I'm sat at a different terminal I still end up saying "I wish I was using Acme".
> - Unless is it part of a grander plan (no pun intended), can we move
> the process interrupt key from Del to something else and have the
> conventional functionality of del back ?
It depends who's conventions.
> - Why arent there more applications and more developers interested
> in developing for plan9 ?
file name completion
> This is a lesson that could learned from the Win32's,
> if you want the OS to grow, you have to get people comfortable with
> it very fast. I think we can make that.
After ten years of Windows I'm not sure people are comfortable with it.
It's clunky, crashes without explanation, brittle to end user fiddling, repeatedly exposes remote root exploits, is expensive, closed source. I need not go on.
> One Ring to rule them all, One Ring to find them,
> One Ring to bring them all and in the darkness bind them.
> (Lord of the Rings)
Arntcha sick of those mobiles phones yet?
Matt
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Getting started in Plan9 - help
2002-01-20 21:01 ` Matt H
@ 2002-01-20 22:02 ` Scott Schwartz
2002-01-22 9:54 ` ozan s yigit
2002-01-21 10:22 ` Boyd Roberts
1 sibling, 1 reply; 187+ messages in thread
From: Scott Schwartz @ 2002-01-20 22:02 UTC (permalink / raw)
To: 9fans
| yes, well, you see plan9 is more mouse driven. eventually you'll
| probably end up with Acme as much your "shell" as anything, and you'll
| find auto complete is unneccessary.
I think that input prediction, if done well, is a beautiful feature, and
one that would fit very well with acme, or maybe as a kind of plumbing. I
used to use a unix thing called "rk"; a markov chain style thing that
continuously prompted you with a line or two of predicted input. You
used the arrow keys or tab or ctrl-m to accept the next char/word/line
of the prediction. It was uncannily good. A lot of command line stuff is
very repetative, and anyone who's seen Rob's fake usenet postings can
see how good this kind of thing is for email. One of these days I'll
get around to hacking it into acme, maybe.
| > - Unless is it part of a grander plan (no pun intended), can we move
| > the process interrupt key from Del to something else and have the
| > conventional functionality of del back ?
Especially since PC keyboards have an actual "break" key to use.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Getting started in Plan9 - help
2002-01-20 22:02 ` Scott Schwartz
@ 2002-01-22 9:54 ` ozan s yigit
2002-01-23 10:05 ` Bakul Shah
0 siblings, 1 reply; 187+ messages in thread
From: ozan s yigit @ 2002-01-22 9:54 UTC (permalink / raw)
To: 9fans
schwartz@bio.cse.psu.edu (Scott Schwartz) writes:
> used to use a unix thing called "rk"; a markov chain style thing that
> continuously prompted you with a line or two of predicted input.
it is "reactive keyboard" and i believe was a thesis work at university
of calgary, by Darragh under Witten. i'm sure a web search would still turn
up pointers. there is a book about it, not sure if still in print. the
interface was interesting in trying to accomodate disabled people to
interact with command interfaces by predictive completion.
oz
--
www.cs.yorku.ca/~oz | if you couldn't find any weirdness, maybe
york u. computer science | we'll just have to make some! -- hobbes
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Getting started in Plan9 - help
2002-01-20 21:01 ` Matt H
2002-01-20 22:02 ` Scott Schwartz
@ 2002-01-21 10:22 ` Boyd Roberts
2002-01-21 10:40 ` John Murdie
1 sibling, 1 reply; 187+ messages in thread
From: Boyd Roberts @ 2002-01-21 10:22 UTC (permalink / raw)
To: 9fans
Matt H wrote:
> > - Why doesnt/Can rc have autocomplete and filename completion as in
> > bash ? This has become so neccessary.
> yes, well, you see plan9 is more mouse driven. eventually you'll probably end up with Acme as much your "shell" as anything, and you'll find auto complete is unneccessary.
> But you're right, it is a nice feature of the bash shell but then there are soooo many goddam directories on a Linux/FreeBSD box and auto complete is Bash's way of trying to alleviate the pain. If you miss it too much I'm sure you could just write a shell script to monitor /dev/cons for tabs, and echo the stuff into /dev/cons.
> Personally, I do prefer having the screen as free form is plan9's is. The shell is more than the commands you can type, it's where you can type them.
I remember the major flamewar over whether Byron's unix implementation of rc
should do this; I was in the 'no way' camp. The result was that you could
conditionally compile in that readline trash. You could probably pick it out
and stick into Plan 9's rc if you wanted to, but Plan 9 is not unix. It has
much better ways to do things.
I guess another way to do it is to use pipefile. One of the Kenji's (iirc)
did this for japanese input -- now there's a problem for you.
As for Latin-1: "Fco. J. Ballesteros" <nemo@plan9.escet.urjc.es> has volunteered
to clean up what I did late last year (I'm too busy). If anyone wants it I'll
send it on or put it on a web page somewhere. I think the only problem is the
caps-lock/ctrl key swap.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Getting started in Plan9 - help
2002-01-21 10:22 ` Boyd Roberts
@ 2002-01-21 10:40 ` John Murdie
0 siblings, 0 replies; 187+ messages in thread
From: John Murdie @ 2002-01-21 10:40 UTC (permalink / raw)
To: 9fans; +Cc: John Murdie
> - Why doesnt/Can rc have autocomplete and filename completion as in
> bash ? This has become so neccessary.
If you put the command history editor in the shell, then you can only
use it in the shell; if you use another shell from time to time, then
you have to learn to use that shell's (different) history mechanism.
It's far better to use a single, general, command history mechanism
provided by your terminal emulator or Acme (which is so more than a
terminal emulator). There is a slight loss from the shell and the
command history editor being separated, I know.
Incidentally, I hate command completion predictors; they remember my
typing mistakes days, weeks or months later, either hesitating to show
me the full, correct, command because of my previous mistake or, worse,
confidently complete my command with the mistake!
--
John A. Murdie
Experimental Officer (Software)
Department of Computer Science
University of York
England
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Getting started in Plan9 - help
2002-01-20 20:02 [9fans] Getting started in Plan9 - help Roshan James
2002-01-20 21:01 ` Matt H
@ 2002-01-20 21:03 ` William S.
2002-01-20 21:34 ` William Josephson
2002-01-21 6:53 ` cej
3 siblings, 0 replies; 187+ messages in thread
From: William S. @ 2002-01-20 21:03 UTC (permalink / raw)
To: 9fans
I can answer this one:
step one: (at the prompt type) a:
step two: cd /n/a:
Bill
Amsterdam, NL
On Mon, Jan 21, 2002 at 01:32:35AM +0530, Roshan James wrote:
<<snip>>
>
> - How can i access the floppy a: ? /n/a: exists but shows no files.
<<snip>>
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Getting started in Plan9 - help
2002-01-20 20:02 [9fans] Getting started in Plan9 - help Roshan James
2002-01-20 21:01 ` Matt H
2002-01-20 21:03 ` William S.
@ 2002-01-20 21:34 ` William Josephson
2002-01-21 6:53 ` cej
3 siblings, 0 replies; 187+ messages in thread
From: William Josephson @ 2002-01-20 21:34 UTC (permalink / raw)
To: 9fans
On Mon, Jan 21, 2002 at 01:32:35AM +0530, Roshan James wrote:
> - Why doesnt/Can rc have autocomplete and filename completion as in
> bash ? This has become so neccessary.
binding everything on to /bin mostly remove the need for this.
If you haven't done so already, I would suggest grabbing the
various shell scripts and C programs from Russ Cox's web
page at www.eecs.harvard.edu/~rsc. " and "" are very useful
in conjunction with the mouse.
-WJ
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] Getting started in Plan9 - help
2002-01-20 20:02 [9fans] Getting started in Plan9 - help Roshan James
` (2 preceding siblings ...)
2002-01-20 21:34 ` William Josephson
@ 2002-01-21 6:53 ` cej
3 siblings, 0 replies; 187+ messages in thread
From: cej @ 2002-01-21 6:53 UTC (permalink / raw)
To: 9fans
Rosh,
you can find some stupid scripts, including "find", at
http://cejchan.gli.cas.cz/plan9
Cheers,
--pac
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] venti
@ 2002-01-30 20:35 George Michaelson
0 siblings, 0 replies; 187+ messages in thread
From: George Michaelson @ 2002-01-30 20:35 UTC (permalink / raw)
To: 9fans
Say you co-elesce the same blockset down to one common instance for
a large number of files, and then lose that block because a fly shits
on the write-once media.
Didn't you just lose that bitpattern in time, across your entire archival
filestore? Oooh. me no like. I suppose that is exactly what happens to
99% of dataloss anyway, if you believe its mostly unique data.
This is precicely why holotype fossils are not on display: they are too
valuable to expose to risk of catastrophic loss.
Protection of an entire venti filestore would thus mean either 2x the data
size to replicate, or some sub-fraction to ECC check it, for some chosen
level of protection. I suppose thats still better than having 300 repeat
instances of the BSD copyright on every manpage. I notice in the paper
the authors say "doable, but we didn't bother" which means until somebody
in the operations space does budget-up for the offsite archive, and some
checks to make sure the copy is 1:1 acceptable, the venti filestore is
a bit more risky than you might want. Even backed on RAID5, it can lose
bigtime from some failures. Might be nice for @home fs, on IDE raid mind you!
This also looks to have resonances with rsync, in a data persistant state
instead of for update of two copies of the same resource. The rsync papers
discuss finding good hash algs and good blocksizes to make this work. No
citation, perhaps if you followed the rsync citation index back they'd wind
up in the same prime sources. I guess the venti authors knew about rsync but
don't see it as having relevance.
Do you get nice COW form savings in memory/load time because every pointer
can walk through the same memory reference to find the string? That could
be really nice!
And, it would make smaller footprints on tiny devices as well.
cheers
-George
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] bug or a feature?
@ 2002-06-13 20:58 Dan Cross
2002-06-13 21:34 ` Tharaneedharan Vilwanathan
0 siblings, 1 reply; 187+ messages in thread
From: Dan Cross @ 2002-06-13 20:58 UTC (permalink / raw)
To: 9fans
> > The rationale is explained in the following paragraphs, but apparantly,
> > Unix rc has fixed that. Indeed, the specific example given in td's
> > paper is handled in a reasonable way.
>
> requiring braces is just as much of a hack
> as if not.
Err, Unix rc doesn't require braces for td's example. requiring a newline
or ; seperator certainly isn't any better, though, for the else case.
- Dan C.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] bug or a feature?
2002-06-13 20:58 [9fans] bug or a feature? Dan Cross
@ 2002-06-13 21:34 ` Tharaneedharan Vilwanathan
2002-06-13 22:51 ` [9fans] venti Tharaneedharan Vilwanathan
0 siblings, 1 reply; 187+ messages in thread
From: Tharaneedharan Vilwanathan @ 2002-06-13 21:34 UTC (permalink / raw)
To: 9fans
Hi,
I used regular files to try venti and did just like the example in the man
page says.
I faced 2 problems. The man page says what should be the size of the index
file nor the utility takes a default value (in contrast, fmtarenas takes a
default value). For 512MB arena file, what should be the sie of the index
file? I created two 50MB files. Am I right?
Next, after doing all the steps given in the example, I tried to do 'vac' on
a directory. It said like "no space left". I tried to vac a small file.
Still the same problem.
Any clues?
Thanks
dharani
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] venti
2002-06-13 21:34 ` Tharaneedharan Vilwanathan
@ 2002-06-13 22:51 ` Tharaneedharan Vilwanathan
2002-06-14 2:19 ` Sean Quinlan
0 siblings, 1 reply; 187+ messages in thread
From: Tharaneedharan Vilwanathan @ 2002-06-13 22:51 UTC (permalink / raw)
To: 9fans
> I used regular files to try venti and did just like the example in the man
> page says.
>
> I faced 2 problems. The man page says what should be the size of the index
i meant, the man page doesnt say a reasonable file size for the index file.
> file nor the utility takes a default value (in contrast, fmtarenas takes a
> default value). For 512MB arena file, what should be the sie of the index
> file? I created two 50MB files. Am I right?
>
> Next, after doing all the steps given in the example, I tried to do 'vac'
on
> a directory. It said like "no space left". I tried to vac a small file.
> Still the same problem.
>
> Any clues?
>
> Thanks
> dharani
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2002-06-13 22:51 ` [9fans] venti Tharaneedharan Vilwanathan
@ 2002-06-14 2:19 ` Sean Quinlan
2002-06-14 5:05 ` Tharaneedharan Vilwanathan
0 siblings, 1 reply; 187+ messages in thread
From: Sean Quinlan @ 2002-06-14 2:19 UTC (permalink / raw)
To: 9fans
your are right, the manual page should give you a hint.
5% is probably a good choice.
The "no space left" sounds like venti is not detecting your arenas.
you might try
hget http://yourmachine/storage
to get a dump of what the venti server thinks it has for storage.
hope this helps
seanq
Tharaneedharan Vilwanathan wrote:
>
> > I used regular files to try venti and did just like the example in the man
> > page says.
> >
> > I faced 2 problems. The man page says what should be the size of the index
> i meant, the man page doesnt say a reasonable file size for the index file.
>
> > file nor the utility takes a default value (in contrast, fmtarenas takes a
> > default value). For 512MB arena file, what should be the sie of the index
> > file? I created two 50MB files. Am I right?
> >
> > Next, after doing all the steps given in the example, I tried to do 'vac'
> on
> > a directory. It said like "no space left". I tried to vac a small file.
> > Still the same problem.
> >
> > Any clues?
> >
> > Thanks
> > dharani
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2002-06-14 2:19 ` Sean Quinlan
@ 2002-06-14 5:05 ` Tharaneedharan Vilwanathan
0 siblings, 0 replies; 187+ messages in thread
From: Tharaneedharan Vilwanathan @ 2002-06-14 5:05 UTC (permalink / raw)
To: 9fans
hi,
sean's mail was useful.
i figured that i created the arena file with exactly 512MB size and did
fmtarenas. that probably didnt make any useful arenas. i raised the size to
nearly 2GB and then it created about 4 arenas. and that solved the problem.
wow! i think venti is going to be a great tool! all along, i was
uncomfortable using source code control systems. i think venti is going to
be a pain killer.
now, i have some questions:
- when the arena file is too small to create any useful arenas, does
fmtarenas throw an appropriate error? and would it be a good idea to give a
clue (in the man page) on the additional space needed for storing additional
details (for e.g: the space needed is (n * arenasize) + some_constant_size).
- in the arena file i created, the last arena size seemed to be less that
the other arena files. is it fine? if so, is it that arena file should
atleast hold one arena and the last arena could be a smaller one?
- how do i gracefully shutdown venti? i closed the window to shutdown venti.
- the http built-in server didnt seem to start by default. however, when i
used -h option, it worked. bug? feature? and when venti is killed (like the
way i did), the built-in http server didnt seem to die.
dharani
> your are right, the manual page should give you a hint.
> 5% is probably a good choice.
>
> The "no space left" sounds like venti is not detecting your arenas.
> you might try
> hget http://yourmachine/storage
> to get a dump of what the venti server thinks it has for storage.
>
> hope this helps
> seanq
>
> Tharaneedharan Vilwanathan wrote:
> >
> > > I used regular files to try venti and did just like the example in the
man
> > > page says.
> > >
> > > I faced 2 problems. The man page says what should be the size of the
index
> > i meant, the man page doesnt say a reasonable file size for the index
file.
> >
> > > file nor the utility takes a default value (in contrast, fmtarenas
takes a
> > > default value). For 512MB arena file, what should be the sie of the
index
> > > file? I created two 50MB files. Am I right?
> > >
> > > Next, after doing all the steps given in the example, I tried to do
'vac'
> > on
> > > a directory. It said like "no space left". I tried to vac a small
file.
> > > Still the same problem.
> > >
> > > Any clues?
> > >
> > > Thanks
> > > dharani
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] venti
@ 2002-11-29 18:27 Russ Cox
0 siblings, 0 replies; 187+ messages in thread
From: Russ Cox @ 2002-11-29 18:27 UTC (permalink / raw)
To: 9fans
[A side note:
A number of people have reported not being able to connect
to sources.cs.bell-labs.com. Our external DNS seems to be
very slow. I'm not sure exactly what's wrong, but until we
fix it you can use:
echo 'dom=sources.cs.bell-labs.com sys=sources ip=204.178.31.8' >>/net/ndb
echo -n refresh >/net/cs
as a workaround.]
There's a new command venti/wrarena, which complements rdarena.
From ventiaux(8):
venti/wrarena [ -o fileoffset ] [ -h host ] arenafile [
clumpoffset ]
Wrarena writes the blocks contained in the arena arenafile
(typically, the output of rdarena) to a Venti server. It is
typically used to reinitialize a Venti server from backups
of the arenas. For example,
venti/rdarena /dev/sdC0/arenas arena.0 >external.media
venti/wrarena -h venti2 external.media
writes the blocks contained in arena.0 to the Venti server
venti2 (typically not the one using /dev/sdC0/arenas).
The -o option specifies that the arena starts at byte
fileoffset (default 0) in arenafile . This is useful for
reading directly from the Venti arena partition:
venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas
(In this example, 335872 is the offset shown in the Venti
server's index list (344064) minus one block (8192). You
will need to substitute your own arena offsets and block
size.)
Finally, the optional offset argument specifies that the
writing should begin with the clump starting at offset
within the arena. Wrarena prints the offset it stopped at
(because there were no more data blocks). This could be
used to incrementally back up a Venti server to another
Venti server:
last=`{cat last}
venti/wrarena -h venti2 -o 335872 /dev/sdC0/arenas $last >output
awk '/^end offset/ { print $3 }' output >last
(Of course, one would need to add wrapper code to keep track
of which arenas have been processed.)
Russ
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
@ 2002-11-29 18:59 Russ Cox
0 siblings, 0 replies; 187+ messages in thread
From: Russ Cox @ 2002-11-29 18:59 UTC (permalink / raw)
To: 9fans, fst
Skip writes [in private mail]:
> Russ, I have been having the same problem for the last
> 1-2 days. The problem seems to be with timeouts and
> not the DNS; Notice the ping and the before/after
> behavior of adding the entry sources.cs. to /net/ndb.
Right, the echo to /net/ndb will make the name resolve at all
(after the real DNS times out).
Srv only gives dial() 5 seconds to establish the connection,
so you're still getting problems. To work around this, you
can establish /srv/sources yourself:
srv 204.178.31.8 sources
Then there will still be a long pause for "9fs sources"
while factotum dials sources for tickets, but at least it
will work.
In summary, the right incantation is:
echo 'dom=sources.cs.bell-labs.com sys=sources ip=204.178.31.2' >>/net/ndb
echo -n refresh >/net/cs
srv 204.178.31.8 sources
9fs sources # takes a while
Sorry for the inconvenience. I have no idea what's wrong
with DNS right now.
Russ
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] venti
@ 2003-02-06 1:11 Kenji Arisawa
2003-02-06 1:21 ` Russ Cox
0 siblings, 1 reply; 187+ messages in thread
From: Kenji Arisawa @ 2003-02-06 1:11 UTC (permalink / raw)
To: 9fans
Hello,
How can we get information that venti have got worked?
The following is my script in /rc/bin/termrc but I am not satisfied:
v=/usr/arisawa/venti
venti/venti -h tcp!*!8088 -w -c $v/venti.conf >[2] /dev/null &
sleep 5 ### I dislike this sloppy solution but don't know alternative
fossil/fossil -c '. '$v/flproto
How are you doing with this problem?
Kenji Arisawa
E-mail: arisawa@aichi-u.ac.jp
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] venti
@ 2007-03-30 16:32 Steve Simon
0 siblings, 0 replies; 187+ messages in thread
From: Steve Simon @ 2007-03-30 16:32 UTC (permalink / raw)
To: 9fans
Just to put another point of view...
I have been using venti at work and at home, and I have no UPSs (UPI ?).
As yet (touch wood) I have only ever lost a maximum of days work, and this
was due to a disk failure taking out my fossil drive which I don't bother
to mirror.
I have never had any data corruption or loss in my venti archive.
Perhaps this is because I only write to it using fossil snapshots at 4am
and not using vac - so the window when the system is vunerable is smaller.
-Steve
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] Venti
@ 2007-07-03 4:58 Lucio De Re
0 siblings, 0 replies; 187+ messages in thread
From: Lucio De Re @ 2007-07-03 4:58 UTC (permalink / raw)
To: 9fans
[-- Attachment #1: Type: text/plain, Size: 548 bytes --]
A fresh installation of Fossil+Venti (CD from June 28 - 9pccpuf built
without alterations) seems to cause Venti trouble.
I start the system up in the late evening and shut it down around 05:00,
but I have moved the Venti archiving function to 01:00 (snap -a 0100).
This morning I got the attached errors. Well, I would have attached
them, but the floppy disk failed on me :-( so we get the first few:
The gist is a whole lot of "unwritten clumps" that go away after a
"checkarenas -f". Something fell off the update truck?
++L
[-- Attachment #2: venti.chk --]
[-- Type: text/plain, Size: 4140 bytes --]
unwritten clump info for clump=61490 score=0860e754dc1654ae7e50e48bce44d873e2f5bd9f type=13
unwritten clump info for clump=61491 score=135d0fa4d2ee35fbf725d1d4459605de5ea68565 type=13
unwritten clump info for clump=61492 score=cfa64faf2975bcc2016f8339344d34496f672651 type=13
unwritten clump info for clump=61493 score=179ce20fdb20c895048a55b7b8af431e00dce6da type=2
unwritten clump info for clump=61494 score=02fd78e36bdf30f897489228d7ba591744f9121a type=13
unwritten clump info for clump=61495 score=dbc05aaaeb555b6c8f359bab2c9c5a0449079675 type=13
unwritten clump info for clump=61496 score=c27057e59ca43886fcf799b1f54f9d5564b19a47 type=2
unwritten clump info for clump=61497 score=44499aaab6f13f01b860dd62f68450d34947b78a type=13
unwritten clump info for clump=61498 score=463510b5675611440e0bf665e3c16f38bad63615 type=13
unwritten clump info for clump=61499 score=7f86bb329206d5b0be49fdeda3faa74491dccd24 type=2
unwritten clump info for clump=61500 score=ab6f69145259eee0fc90f633fdc2b4ca3b46b9f5 type=13
unwritten clump info for clump=61501 score=f15b45e306bd8335b8a127f9dfbe32748714f87b type=2
unwritten clump info for clump=61502 score=8920bb02529e41f65937d2defff5589419a5ee53 type=13
unwritten clump info for clump=61503 score=efc693b46063ef62b5c380f8ee29ff7004a35ad9 type=2
unwritten clump info for clump=61504 score=9833974abec1a0617a2261f3597216f7cc4cf03f type=13
unwritten clump info for clump=61505 score=82a4cf34000d1311caa6b0632a7fa7d2e99903df type=2
unwritten clump info for clump=61506 score=6be5fa65dd41f918d611c12ee25e902eba668587 type=13
unwritten clump info for clump=61507 score=6b2eed0ceeec06debae31a8ba75bb2413dd857f5 type=13
unwritten clump info for clump=61508 score=bf58c52de0abed8c693da15f290beba937df85b3 type=13
unwritten clump info for clump=61509 score=42dcb7eac6ca00d94c60ecd55e577170f97a825d type=13
unwritten clump info for clump=61510 score=9eb8621106fde5b827b4a36c68ad8ba5216f60a0 type=13
unwritten clump info for clump=61511 score=a1c88fc8e707cd3efae8eb62ee427fd5d033b9bc type=13
unwritten clump info for clump=61512 score=02cadf200ad0c422a05b2a711629acc77f243e31 type=13
unwritten clump info for clump=61513 score=562a63303eec23ad1e9488855d58769c673d35d9 type=2
unwritten clump info for clump=61514 score=ac69e9fc45030c172c8046bd7f1ad0276e9e0587 type=13
unwritten clump info for clump=61515 score=9c4de45cedf8d1981151bae318af883fe6bca4c0 type=13
unwritten clump info for clump=61516 score=773041b6cd72be21f3f255e41aac3e37926abf2c type=2
unwritten clump info for clump=61517 score=d33c06bc7fa6c50692bd6707a6c3e5d2f1830392 type=3
unwritten clump info for clump=61518 score=781a674e66e3d8002a056b16dbfa31ad74a8fbbd type=13
unwritten clump info for clump=61519 score=ca81cf2d4e98827d6a30471528e523c33b76d04a type=13
unwritten clump info for clump=61520 score=9c34ffb4192da23393682d7250cf10aeb5dc446d type=13
unwritten clump info for clump=61521 score=34f6057f0f839d2580a0c0750762766a8121aa6e type=3
unwritten clump info for clump=61522 score=30c65b53b202a4dcac2de992eb4a409cde24e881 type=2
unwritten clump info for clump=61523 score=41724f3c5016052ff1f1d4ca1faa1299904a4e91 type=13
unwritten clump info for clump=61524 score=6293b09977241d09aaf4c11a2fafc20f14bf1da7 type=13
unwritten clump info for clump=61525 score=bb3ff1d517677dc7ac158140a4416c0c02b589bf type=13
unwritten clump info for clump=61526 score=70fdd1b2179e5d9fbed0862eae4ad922b7e0a678 type=13
unwritten clump info for clump=61527 score=7bc69e87a0db7f5c4435a46dfdb7befc6ce0efaf type=2
unwritten clump info for clump=61528 score=cbc59724623d2c52b3bd7e0eab471694b381d842 type=13
unwritten clump info for clump=61529 score=9bbc6c175331223ef9973b8534b72a4d3050c7ce type=13
unwritten clump info for clump=61530 score=b620b786813702d0d50b186149b08aa64f7eb703 type=13
unwritten clump info for clump=61531 score=e540dc94f339e1963cb499dbaae7b8aa9437846f type=3
unwritten clump info for clump=61532 score=b217dca96e4629595a328ba86b24259420fc1154 type=13
unwritten clump info for clump=61533 score=6d7098719406013797606870c300e5c8b277db84 type=2
unwritten clump info for clump=61534 score=7b3250f73ed703f7bc3
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] venti
@ 2007-10-04 1:51 Russ Cox
2007-10-07 20:51 ` Steve Simon
0 siblings, 1 reply; 187+ messages in thread
From: Russ Cox @ 2007-10-04 1:51 UTC (permalink / raw)
To: 9fans
I have fixed the sync livelock bug that anothy and others reported.
To make it easier to debug problems in the future (and to inspect
your venti servers from other machines), I suggest changing your
plan9.ini from reading
venti=/dev/sdC0/arenas
to
venti=/dev/sdC0/arenas tcp!127.1!17034 tcp!*!8000
The two additional addresses are where venti listens for venti
and http traffic, respectively. The defaults are tcp!127.1!17034
and tcp!127.1!8000. Using * instead of 127.1 in the latter will
make it so the http server is accessible from other machines.
(If you want to make your venti server accessible too, change
the first address to tcp!*!17034.) The default is 127.1 for
security reasons.
Having done this, you will be able to load pages like
http://venti:8000/proc/threads
to get a list of threads and what code they are blocked in. And
http://venti:8000/proc/stacks
will give the stack for each thread, much like running stacks()
in an "acid -l thread" session.
If you do encounter problems where venti appears to be
hung in some form, I would appreciate if you could save
the output of
http://venti:8000/proc/all
and mail it to me when reporting the problem.
Note that although there are new venti binaries on sources,
the kernels do not yet use the new venti. If you boot from
a combined venti+fossil server, you will need to rebuild
9pccpuf/9pcf yourself in order to get it.
Thanks.
Russ
^ permalink raw reply [flat|nested] 187+ messages in thread
* [9fans] venti
@ 2009-01-09 8:20 Tharaneedharan Vilwanathan
2009-01-09 9:44 ` Sape Mullender
0 siblings, 1 reply; 187+ messages in thread
From: Tharaneedharan Vilwanathan @ 2009-01-09 8:20 UTC (permalink / raw)
To: Fans of the OS Plan 9 from Bell Labs
hi,
i noticed something odd with venti and i am just trying to see if this
is an issue and if this needs to be addressed.
i think, by default, plan9 installation sets localhost as the address
for venti in plan9.ini. but at some point i wanted venti to announce
any (*) address. for some reason, i simply started venti/venti -a
'tcp!*!17034' to make it so. after this, i did vac from another
machine and it archived data. after sometime, i realized i may be
running venti on the same venti data area twice. when i did 'ps', it
looked like that. then i rebooted the machine and then tried
'dumpvacroots.new' command (from contrib). i noticed that venti arena
was corrupted. this is what i remember and if required i can try to
reproduce the issue.
the question i have is, is there any protection that prevents someone
from doing this accidentally? something like the last active venti
arena is marked 'IN_USE' so that if another instance of venti is
started (with read-write access), it can check for this? i agree user
has to be careful but given that venti archive is so critical, we
should avoid any accidental damage.
please pass your views.
thanks
dharani
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2009-01-09 8:20 Tharaneedharan Vilwanathan
@ 2009-01-09 9:44 ` Sape Mullender
2009-01-09 12:18 ` Richard Miller
2009-01-09 20:11 ` Dave Eckhardt
0 siblings, 2 replies; 187+ messages in thread
From: Sape Mullender @ 2009-01-09 9:44 UTC (permalink / raw)
To: 9fans
> i noticed something odd with venti and i am just trying to see if this
> is an issue and if this needs to be addressed.
>
> i think, by default, plan9 installation sets localhost as the address
> for venti in plan9.ini. but at some point i wanted venti to announce
> any (*) address. for some reason, i simply started venti/venti -a
> 'tcp!*!17034' to make it so. after this, i did vac from another
> machine and it archived data. after sometime, i realized i may be
> running venti on the same venti data area twice. when i did 'ps', it
> looked like that. then i rebooted the machine and then tried
> 'dumpvacroots.new' command (from contrib). i noticed that venti arena
> was corrupted. this is what i remember and if required i can try to
> reproduce the issue.
>
> the question i have is, is there any protection that prevents someone
> from doing this accidentally? something like the last active venti
> arena is marked 'IN_USE' so that if another instance of venti is
> started (with read-write access), it can check for this? i agree user
> has to be careful but given that venti archive is so critical, we
> should avoid any accidental damage.
Hmm. Running two ventis on the same data is, of course, bad. It's also
something I haven't seen happen before. A check could be put in by having
venti put some sort of lock somewhere on the disk. But that would lead
to problems if venti doesn't shut down properly: venti would be gone
but the lock would still be there. You run the risk of not being able
to boot your machine. I think you should just learn to be careful.
Sape
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2009-01-09 9:44 ` Sape Mullender
@ 2009-01-09 12:18 ` Richard Miller
2009-01-09 12:38 ` Sape Mullender
2009-01-09 13:39 ` erik quanstrom
2009-01-09 20:11 ` Dave Eckhardt
1 sibling, 2 replies; 187+ messages in thread
From: Richard Miller @ 2009-01-09 12:18 UTC (permalink / raw)
To: 9fans
> Hmm. Running two ventis on the same data is, of course, bad. It's also
> something I haven't seen happen before.
I think it may have happened to me. Recently I had a "missing score" error
when I was looking for something in my dump fs. To assess the damage I did
a 'venti/copy -r' to a spare server, which told me 13 pointers had to be
rewritten.
I do sometimes get errors like this from my fossil server:
could not write super block; waiting 10 seconds
blistAlloc: called on clean block
but I've been assuming they are benign. Am I wrong?
My understanding of fossil is that venti writes are ordered such that
the store should not be left in an inconsistent state even after a
sudden shutdown. If that's the case, I'm guessing the most likely
cause of corruption was a careless experiment with venti when there
was already one running.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2009-01-09 12:18 ` Richard Miller
@ 2009-01-09 12:38 ` Sape Mullender
2009-01-09 13:39 ` erik quanstrom
1 sibling, 0 replies; 187+ messages in thread
From: Sape Mullender @ 2009-01-09 12:38 UTC (permalink / raw)
To: 9fans
[-- Attachment #1: Type: text/plain, Size: 209 bytes --]
Yes, but even if one venti always leaves the store in a consistent
state, running two may still cause them to wite differemt things to
the same place on disk and this is likely to result in havoc.
Sape
[-- Attachment #2: Type: message/rfc822, Size: 2692 bytes --]
From: Richard Miller <9fans@hamnavoe.com>
To: 9fans@9fans.net
Subject: Re: [9fans] venti
Date: Fri, 9 Jan 2009 12:18:35 +0000
Message-ID: <b146f7b71d1aa58ff06d8d63c3b331b4@hamnavoe.com>
> Hmm. Running two ventis on the same data is, of course, bad. It's also
> something I haven't seen happen before.
I think it may have happened to me. Recently I had a "missing score" error
when I was looking for something in my dump fs. To assess the damage I did
a 'venti/copy -r' to a spare server, which told me 13 pointers had to be
rewritten.
I do sometimes get errors like this from my fossil server:
could not write super block; waiting 10 seconds
blistAlloc: called on clean block
but I've been assuming they are benign. Am I wrong?
My understanding of fossil is that venti writes are ordered such that
the store should not be left in an inconsistent state even after a
sudden shutdown. If that's the case, I'm guessing the most likely
cause of corruption was a careless experiment with venti when there
was already one running.
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2009-01-09 12:18 ` Richard Miller
2009-01-09 12:38 ` Sape Mullender
@ 2009-01-09 13:39 ` erik quanstrom
1 sibling, 0 replies; 187+ messages in thread
From: erik quanstrom @ 2009-01-09 13:39 UTC (permalink / raw)
To: 9fans
> I do sometimes get errors like this from my fossil server:
> could not write super block; waiting 10 seconds
> blistAlloc: called on clean block
> but I've been assuming they are benign. Am I wrong?
i looked into this.
/sys/src/cmd/fossil/cache.c:1210,1217
if(p->index < 0){
/*
* We don't know how to temporarily undo
* b's dependency on bb, so just don't write b yet.
*/
if(0) fprint(2, "blockWrite skipping %d %x %d %d; need to write %d %x %d\n",
b->part, b->addr, b->vers, b->l.type, p->part, p->addr, bb->vers);
return 0;
}
what if bb == b?
it'd be interesting to see what that outputs with if(1).
i think _cacheLocalLookup is finding the superblock
itself. perhaps no write between snaps meaning that
only the sb itself is dirty?
- erik
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2009-01-09 9:44 ` Sape Mullender
2009-01-09 12:18 ` Richard Miller
@ 2009-01-09 20:11 ` Dave Eckhardt
2009-01-09 20:27 ` erik quanstrom
` (2 more replies)
1 sibling, 3 replies; 187+ messages in thread
From: Dave Eckhardt @ 2009-01-09 20:11 UTC (permalink / raw)
To: 9fans
> A check could be put in by having venti put some sort of lock
> somewhere on the disk. But that would lead to problems if
> venti doesn't shut down properly: venti would be gone but the
> lock would still be there.
Post an (ignored) mode 000 fd in /srv? Since nobody could open
it, it would always have one reference, and would go away when
the venti did?
Dave Eckhardt
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2009-01-09 20:11 ` Dave Eckhardt
@ 2009-01-09 20:27 ` erik quanstrom
2009-01-09 22:18 ` Dave Eckhardt
2009-01-09 20:34 ` Steve Simon
2009-01-09 21:08 ` Roman V. Shaposhnik
2 siblings, 1 reply; 187+ messages in thread
From: erik quanstrom @ 2009-01-09 20:27 UTC (permalink / raw)
To: 9fans
> > A check could be put in by having venti put some sort of lock
> > somewhere on the disk. But that would lead to problems if
> > venti doesn't shut down properly: venti would be gone but the
> > lock would still be there.
>
> Post an (ignored) mode 000 fd in /srv? Since nobody could open
> it, it would always have one reference, and would go away when
> the venti did?
dns tries a similar trick. unfortunately, this means that dns
doesn't like to be restarted when it's gone haywire as slay dns|rc
doesn't seem to remove dns' entry from srv.
it also assumes direct-attach storage.
- erik
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2009-01-09 20:27 ` erik quanstrom
@ 2009-01-09 22:18 ` Dave Eckhardt
2009-01-09 22:27 ` erik quanstrom
0 siblings, 1 reply; 187+ messages in thread
From: Dave Eckhardt @ 2009-01-09 22:18 UTC (permalink / raw)
To: 9fans
>> Post an (ignored) mode 000 fd in /srv? Since nobody could open
>> it, it would always have one reference, and would go away when
>> the venti did?
> dns tries a similar trick.
I think /srv/dns serves an actual file system, so there are
potentially many references to it (not just one).
> it also assumes direct-attach storage.
Not exactly, but you are right that ventis running on two
kernels could mount the same storage.
I seem to recall being surprised at some point to observe
/dev/sdXX/data silently imposing a one-open-at-a-time policy
(I think subsequent opens stalled). Maybe a script run at
system boot time could turn on DMEXCL for appropriate things
in /dev/sd*/*?
Dave Eckhardt
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2009-01-09 22:18 ` Dave Eckhardt
@ 2009-01-09 22:27 ` erik quanstrom
0 siblings, 0 replies; 187+ messages in thread
From: erik quanstrom @ 2009-01-09 22:27 UTC (permalink / raw)
To: 9fans
> I seem to recall being surprised at some point to observe
> /dev/sdXX/data silently imposing a one-open-at-a-time policy
> (I think subsequent opens stalled). Maybe a script run at
> system boot time could turn on DMEXCL for appropriate things
> in /dev/sd*/*?
i think you mean the raw file.
; cat fu.c
#include <u.h>
#include <libc.h>
void
main(void)
{
int i, fd[2];
for(i = 0; i < nelem(fd); i++){
fd[i] = open("/dev/sdC0/data", OREAD);
print("fd = %d\n", fd[i]);
}
exits("");
}
; 8c fu.c && 8l fu.8 && 8.out
3
4
- erik
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2009-01-09 20:11 ` Dave Eckhardt
2009-01-09 20:27 ` erik quanstrom
@ 2009-01-09 20:34 ` Steve Simon
2009-01-09 21:08 ` Roman V. Shaposhnik
2 siblings, 0 replies; 187+ messages in thread
From: Steve Simon @ 2009-01-09 20:34 UTC (permalink / raw)
To: 9fans
> Post an (ignored) mode 000 fd in /srv? Since nobody could open
> it, it would always have one reference, and would go away when
> the venti did?
Kudos to Mr Eckhardt for a very neat solution.
-Steve
^ permalink raw reply [flat|nested] 187+ messages in thread
* Re: [9fans] venti
2009-01-09 20:11 ` Dave Eckhardt
2009-01-09 20:27 ` erik quanstrom
2009-01-09 20:34 ` Steve Simon
@ 2009-01-09 21:08 ` Roman V. Shaposhnik
2 siblings, 0 replies; 187+ messages in thread
From: Roman V. Shaposhnik @ 2009-01-09 21:08 UTC (permalink / raw)
To: Fans of the OS Plan 9 from Bell Labs
On Fri, 2009-01-09 at 15:11 -0500, Dave Eckhardt wrote:
> > A check could be put in by having venti put some sort of lock
> > somewhere on the disk. But that would lead to problems if
> > venti doesn't shut down properly: venti would be gone but the
> > lock would still be there.
>
> Post an (ignored) mode 000 fd in /srv? Since nobody could open
> it, it would always have one reference, and would go away when
> the venti did?
Very neat! One question though: since a hostowner can change
permissions on the entry later, this still doesn't offer
a guarantee of a single reference, does it?
Thanks,
Roman.
^ permalink raw reply [flat|nested] 187+ messages in thread
end of thread, other threads:[~2009-01-09 22:27 UTC | newest]
Thread overview: 187+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2000-08-18 15:34 [9fans] Re: Solaris thread scheaduling rob pike
[not found] ` <rob@plan9.bell-labs.com>
2000-08-02 14:48 ` [9fans] pipefile rob pike
2000-08-02 15:49 ` James A. Robinson
2000-08-18 20:25 ` [9fans] Re: Solaris thread scheaduling Tom Duff
2000-09-06 21:59 ` [9fans] Reliable Cray Y-MP C90 Supercomputer rob pike
2000-09-06 22:02 ` James A. Robinson
2000-09-06 22:14 ` Boyd Roberts
2000-09-06 22:11 ` Boyd Roberts
2000-09-07 22:18 ` [9fans] new versions of graphics programs? Tom Duff
2000-11-01 22:23 ` [9fans] /n/smtp rob pike
2000-11-01 22:38 ` Scott Schwartz
2000-11-24 0:41 ` [9fans] Crazy idea... or a new project? rob pike
2000-11-24 0:48 ` Boyd Roberts
2000-11-24 22:13 ` Scott Schwartz
2000-11-24 22:24 ` Boyd Roberts
2001-02-06 17:11 ` [9fans] azerty [french] keyboard support rob pike
2001-02-06 19:10 ` Scott Schwartz
2001-02-06 19:23 ` Dan Cross
2001-02-07 15:23 ` [9fans] 9p2k, fsync rob pike
2001-02-07 18:42 ` Scott Schwartz
2001-02-08 1:19 ` Dan Cross
2001-02-08 9:43 ` Douglas A. Gwyn
2001-02-14 13:51 ` [9fans] isatty rob pike
2001-02-14 16:42 ` Scott Schwartz
2001-03-26 14:12 ` [9fans] sam mod for delete-forward rob pike
2001-03-26 15:37 ` Douglas A. Gwyn
2001-03-27 8:25 ` Boyd Roberts
2001-03-27 14:01 ` Sam
2001-03-27 16:51 ` Dan Cross
2001-03-28 8:37 ` Douglas A. Gwyn
2001-03-29 8:26 ` Boyd Roberts
2001-03-26 15:42 ` Scott Schwartz
2001-05-10 14:59 ` [9fans] snprint(), getfields() specification rob pike
2001-05-10 16:42 ` Scott Schwartz
2001-05-10 18:13 ` Steve Kilbane
2001-05-10 21:38 ` Boyd Roberts
2001-05-11 6:51 ` Steve Kilbane
2001-05-19 14:14 ` Re[4]: [9fans] home, end ^h^j^k^l rob pike
2001-05-19 14:26 ` Re[6]: " Matt H
2001-05-19 22:45 ` [9fans] ls -m Scott Schwartz
2001-05-19 22:50 ` Boyd Roberts
2001-05-19 15:35 ` Re[4]: [9fans] home, end ^h^j^k^l James A. Robinson
2001-05-19 20:36 ` Boyd Roberts
2001-05-19 23:30 ` Richard Elberger
2001-05-20 2:37 ` Boyd Roberts
2001-05-20 7:03 ` Lucio De Re
2001-05-20 11:16 ` paurea
2001-05-20 13:11 ` Boyd Roberts
2001-05-20 13:04 ` Boyd Roberts
2001-05-23 8:24 ` Randolph Fritz
2001-05-23 8:46 ` Re[6]: " Matt H
2001-05-23 9:04 ` Boyd Roberts
2001-05-20 0:16 ` [9fans] ls -m rob pike
2001-05-20 0:31 ` Boyd Roberts
2001-05-20 1:38 ` [9fans] mouse vs key Scott Schwartz
2001-05-20 6:29 ` Dan Cross
2001-05-20 8:09 ` Matt H
2001-05-20 11:35 ` Re[2]: [9fans] mouse vs key - nethack matt
2001-05-20 13:13 ` Boyd Roberts
2001-05-20 12:50 ` [9fans] mouse vs key Boyd Roberts
2001-05-29 4:27 ` [9fans] src vs db rob pike
2001-05-29 4:37 ` Scott Schwartz
2001-07-11 19:22 ` [9fans] sam vs acme rob pike
2001-07-11 20:08 ` James A. Robinson
2001-08-14 12:54 ` [9fans] User Interface rob pike
2001-08-14 15:01 ` James A. Robinson
2001-08-16 13:45 ` phaet0n
2001-08-20 8:57 ` Randolph Fritz
2001-12-02 3:10 ` [9fans] plumb rob pike
2001-12-02 3:31 ` Scott Schwartz
2002-01-30 5:52 ` [9fans] venti rob pike
2002-01-30 6:23 ` George Michaelson
2002-01-30 8:07 ` paurea
2002-01-30 11:17 ` Boyd Roberts
2002-03-01 6:20 ` Fwd: Re: [9fans] samuel (fwd) rob pike
2002-03-01 6:34 ` George Michaelson
2002-03-01 12:04 ` Boyd Roberts
2002-04-27 16:35 ` [9fans] Fourth Release of Plan 9 Now Available rob pike, esq.
2002-04-27 18:24 ` Scott Schwartz
2002-04-27 22:14 ` Laura Creighton
2002-04-29 9:37 ` Andrew
2002-06-28 16:49 ` [9fans] dumb question rob pike, esq.
2002-06-29 2:23 ` Scott Schwartz
2000-09-07 21:57 [9fans] new versions of graphics programs? rob pike
2000-09-07 22:50 ` Jim Choate
[not found] ` <ravage@einstein.ssz.com>
2000-09-07 22:35 ` Tom Duff
2000-09-07 23:24 ` Jim Choate
2000-09-08 15:28 ` please_no_spam_to_
[not found] ` <D.M.Pick@qmw.ac.uk>
2000-09-08 16:43 ` Tom Duff
2001-06-09 17:22 [9fans] could those of you who have students check this out for forsyth
2001-06-09 18:50 ` [9fans] Re: the 'science' in computer science andrey mirtchovski
2001-06-09 17:56 ` Boyd Roberts
2001-06-11 8:27 ` pac
2001-06-11 15:19 ` Dan Cross
2001-06-11 21:43 ` Boyd Roberts
[not found] ` <0cb501c0f2bf$97cacea0$e8b7c6d4@SOMA>
2001-06-11 22:43 ` paurea
2001-06-12 14:18 ` Dan Cross
2001-06-12 15:50 ` Boyd Roberts
2001-06-12 18:48 ` Dan Cross
2001-06-12 0:09 ` Scott Merrilees
2001-06-12 0:16 ` Boyd Roberts
2001-06-12 0:42 ` Scott Merrilees
2001-06-12 1:08 ` Boyd Roberts
[not found] ` <0cc301c0f2c0$78949560$e8b7c6d4@SOMA>
2001-06-12 14:12 ` Dan Cross
2001-06-16 23:34 ` Matt
2001-06-28 21:29 ` Boyd Roberts
2001-06-28 22:03 ` Matt
2001-06-28 23:20 ` George Michaelson
2001-06-29 21:27 ` Boyd Roberts
2001-07-18 15:49 ` Ralph Corderoy
2001-06-29 4:30 ` Lucio De Re
[not found] <vikki@proweb.co.uk>
2001-06-10 17:32 ` [9fans] string to list? vikki
2001-06-10 17:47 ` Boyd Roberts
2001-06-10 17:55 ` Boyd Roberts
2001-06-10 18:03 ` Scott Schwartz
2001-06-10 21:48 ` Matt
2001-06-10 22:24 ` Scott Schwartz
2001-06-10 22:30 ` Boyd Roberts
[not found] <matt@proweb.co.uk>
2001-06-12 0:39 ` [9fans] help, i'm in a wet paper bag and I can't get out Matt
2001-06-12 0:55 ` Scott Schwartz
2001-06-12 1:12 ` Boyd Roberts
2001-06-12 1:00 ` Boyd Roberts
2001-06-12 1:30 ` Jonathan Sergent
2001-06-15 8:27 ` Hermann Samso
2001-06-15 11:53 ` Boyd Roberts
2001-06-15 12:18 ` Matt
2001-06-15 14:01 ` Matt
2001-06-15 14:25 ` Boyd Roberts
2001-06-26 16:33 [9fans] bitsy question John Packer
2001-06-26 17:10 ` [9fans] " Dan Cross
2001-06-26 19:51 ` John Packer
2001-06-26 20:34 ` Dan Cross
2001-06-29 22:32 ` Boyd Roberts
2001-06-27 1:15 ` [9fans] Two cpu servers? Ish Rattan
2001-06-26 20:09 ` [9fans] Re: bitsy question John Packer
2001-06-26 20:36 ` Dan Cross
2001-06-26 20:18 ` Latchesar Ionkov
2001-06-26 20:28 ` Matt
2001-06-26 22:13 ` Steve Kilbane
2001-07-12 8:42 [9fans] architectures forsyth
2001-07-12 13:56 ` Laura Creighton
2001-07-12 16:13 ` Ozan Yigit
2001-07-12 16:33 ` Matt
2001-07-12 18:12 ` Scott Schwartz
2001-07-12 18:16 ` Martin Harriss
2001-07-12 18:43 ` Dan Cross
2001-07-13 14:52 ` Douglas A. Gwyn
2001-07-13 15:13 ` Boyd Roberts
2001-10-25 17:55 [9fans] Virtual memory in BSD and Plan9 Russ Cox
2001-10-25 18:29 ` William Josephson
2001-10-26 8:09 ` [9fans] acme bug/annoyance? Matt
2001-10-26 11:36 ` rob pike
2001-10-26 14:43 ` Scott Schwartz
2001-10-29 10:16 ` [9fans] Virtual memory in BSD and Plan9 John S. Dyson
2002-01-20 20:02 [9fans] Getting started in Plan9 - help Roshan James
2002-01-20 21:01 ` Matt H
2002-01-20 22:02 ` Scott Schwartz
2002-01-22 9:54 ` ozan s yigit
2002-01-23 10:05 ` Bakul Shah
2002-01-21 10:22 ` Boyd Roberts
2002-01-21 10:40 ` John Murdie
2002-01-20 21:03 ` William S.
2002-01-20 21:34 ` William Josephson
2002-01-21 6:53 ` cej
2002-01-30 20:35 [9fans] venti George Michaelson
2002-06-13 20:58 [9fans] bug or a feature? Dan Cross
2002-06-13 21:34 ` Tharaneedharan Vilwanathan
2002-06-13 22:51 ` [9fans] venti Tharaneedharan Vilwanathan
2002-06-14 2:19 ` Sean Quinlan
2002-06-14 5:05 ` Tharaneedharan Vilwanathan
2002-11-29 18:27 Russ Cox
2002-11-29 18:59 Russ Cox
2003-02-06 1:11 Kenji Arisawa
2003-02-06 1:21 ` Russ Cox
2007-03-30 16:32 Steve Simon
2007-07-03 4:58 [9fans] Venti Lucio De Re
2007-10-04 1:51 [9fans] venti Russ Cox
2007-10-07 20:51 ` Steve Simon
2009-01-09 8:20 Tharaneedharan Vilwanathan
2009-01-09 9:44 ` Sape Mullender
2009-01-09 12:18 ` Richard Miller
2009-01-09 12:38 ` Sape Mullender
2009-01-09 13:39 ` erik quanstrom
2009-01-09 20:11 ` Dave Eckhardt
2009-01-09 20:27 ` erik quanstrom
2009-01-09 22:18 ` Dave Eckhardt
2009-01-09 22:27 ` erik quanstrom
2009-01-09 20:34 ` Steve Simon
2009-01-09 21:08 ` Roman V. Shaposhnik
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