[LUAU] programming question, buffer problem?
The retard factor is kicking in on me today. I have a program that uses quite a bit of buffer space. There are four major chunks of buffer space, three declared something like short mybuffer[32][4M], and the fourth int myotherbuffer[4][4M]. Total buffer usage comes in at somewhere under 800MB. In the previous iteration of the program, the data chunks were smaller (1M instead of 4M), and it worked fine, never saw a problem. But now I'm seeing a segmentation fault as soon as I start the program. If I change the 32 to 30, it seems to run fine. Now, I've seen this happen when you declare to large a chunk of data in a function, where I think basically the stack barfs and you get a segmentation fault because the data didn't fit. But these buffers are declared in a header file, and I *thought* that meant they'd be loaded to the heap, and not have the same problem. I kind of remember from somewhere that if you try to load a program that requires greater than half the available heap then this'll happen, but I've got 3GB of ram on this machine, and without this program running, I'm only using about 700MB. So that *shouldn't* be it, at least as I understand it. Any ideas? I could live with 30 buffers per ring, but since I don't know what the real problem is, I don't know if that's even a solution. Thanks in advance, -Charles
Re: [LUAU] programming question, buffer problem?
I have a program that uses quite a bit of buffer space. There are four major chunks of buffer space, three declared something like short mybuffer[32][4M], and the fourth int myotherbuffer[4][4M]. Total buffer usage comes in at somewhere under 800MB. by 4M do you mean 4*1024*1024? Now, I've seen this happen when you declare to large a chunk of data in a function, where I think basically the stack barfs and you get a segmentation fault because the data didn't fit. But these buffers are declared in a header file, and I *thought* that meant they'd be loaded to the heap, and not have the same problem. If you declare local variables (non-static) they are allocated on the stack. If you declare global variables they are either in the BSS or data segment (depending on if they are initialized to zeros or other values). There are limitations on the amount of space available on the stack. I'm not familiar with limitations in the bss/data. However, you can avoid them, if they exist, by allocating the data at runtime using malloc or a similar function. In that case the data will be on the heap. Where in the startup does the crash occur? -Charles Tim N.
Re: [LUAU] programming question, buffer problem?
Charles Lockhart wrote: I kind of remember from somewhere that if you try to load a program that requires greater than half the available heap then this'll happen, but I've got 3GB of ram on this machine, and without this program running, I'm only using about 700MB. So that *shouldn't* be it, at least as I understand it. I take that back. After reconsidering my math and memory usage, that could be the problem.
[LUAU] Virtual directory points to another computer
Aloha, Does anyone know how to have a 'symlink' that will point to a directory on another computer? The applicatoin is to have a local FTP server but the data the user can upload/download would be located on another PC. The link between the two PC's should be encrypted. I saw a little while ago someone wanted a gmail invite, I have about 10 if anyone needs, just send you email address. Aloha, Matt
Re: [LUAU] Virtual directory points to another computer
On Thursday 2004-12-30 10:42, Matt Darnell wrote: Does anyone know how to have a 'symlink' that will point to a directory on another computer? cd the-directory-in-which-to-make-the-symbolic-link ln -s the-directory-pointed-to-by-the-symbolic-link -- All information and transactions are non negotiable and are private between the parties. All rights reserved without prejudice; Copyright 2004 Angela Kahealani. http://www.kahealani.com/
Re: [LUAU] Virtual directory points to another computer
On Thursday 2004-12-30 10:42, Matt Darnell wrote: Aloha, Does anyone know how to have a 'symlink' that will point to a directory on another computer? ummm, yeah, what I said before, AFTER you NFS mount the remote computer's directory. -- All information and transactions are non negotiable and are private between the parties. All rights reserved without prejudice; Copyright 2004 Angela Kahealani. http://www.kahealani.com/
Re: [LUAU] programming question, buffer problem?
Tim Newsham wrote: by 4M do you mean 4*1024*1024? Yeppers. If you declare local variables (non-static) they are allocated on the stack. If you declare global variables they are either in the BSS or data segment (depending on if they are initialized to zeros or other values). There are limitations on the amount of space available on the stack. Exactly, which is why I made them global. I'm not familiar with limitations in the bss/data. However, you can avoid them, if they exist, by allocating the data at runtime using malloc or a similar function. In that case the data will be on the heap. Other than the 1/2 the available memory thing (which may be the culprit), neither am I. We kind of lean away from dynamic allocation for this program. I'm trying to tweak around with sbrk() a bit to see if I can fudge things a bit. Where in the startup does the crash occur? When the program is loaded. Nothing gets executed. Thanks, -Charles
Re: [LUAU] Virtual directory points to another computer
Does anyone know how to have a 'symlink' that will point to a directory on another computer? ummm, yeah, what I said before, AFTER you NFS mount the remote computer's directory. Angela, Thanks for this. Would the link from the FTP server to the host 'file' server be encrypted? The files have some sensitive information that we would like to encrypted. Unfortunately the clients do not support secure FTP. Right now they are pulling the files from a remote FTP server and the sensitive data is beign sent over the line in plain text. We are trying to encrypt the 'public' portion of the FTP journey. Aloha, Matt
Re: [LUAU] Virtual directory points to another computer
On Thu, 30 Dec 2004, Matt Darnell wrote: Does anyone know how to have a 'symlink' that will point to a directory on another computer? ummm, yeah, what I said before, AFTER you NFS mount the remote computer's directory. Angela, Thanks for this. Would the link from the FTP server to the host 'file' server be encrypted? Not with your standard, garden-variety NFS, no. If you implement Kerberos, you can set up secure NFS, and there are one or two other secure NFS implementations floating around out there, but I've never had occasion to use any of them, so I can't give much advice other than google 'em, sorry. IIRC, they're pretty vendor-specific (i.e., Sun has a version, IBM has one for AIX, etc.) I have a feeling that AFS, being kerberos-aware, can support encryption, but I'm not sure. There's an open-source version of that that's alive and active, so I'd check it out. Hope this helps, ND -- Andrew Maddox, madsox squiggle radix point net DC-area martial artist? Check us out and join us at http://sports.groups.yahoo.com/group/DCMartialArts/
Re: [LUAU] Virtual directory points to another computer
You might want to take a look at coda http://www.coda.cs.cmu.edu/ On Thu, 30 Dec 2004 16:46:36 -0500 (EST), Andrew Maddox [EMAIL PROTECTED] wrote: On Thu, 30 Dec 2004, Matt Darnell wrote: Does anyone know how to have a 'symlink' that will point to a directory on another computer? ummm, yeah, what I said before, AFTER you NFS mount the remote computer's directory. Angela, Thanks for this. Would the link from the FTP server to the host 'file' server be encrypted? Not with your standard, garden-variety NFS, no. If you implement Kerberos, you can set up secure NFS, and there are one or two other secure NFS implementations floating around out there, but I've never had occasion to use any of them, so I can't give much advice other than google 'em, sorry. IIRC, they're pretty vendor-specific (i.e., Sun has a version, IBM has one for AIX, etc.) I have a feeling that AFS, being kerberos-aware, can support encryption, but I'm not sure. There's an open-source version of that that's alive and active, so I'd check it out. Hope this helps, ND -- Andrew Maddox, madsox squiggle radix point net DC-area martial artist? Check us out and join us at http://sports.groups.yahoo.com/group/DCMartialArts/ ___ LUAU@lists.hosef.org mailing list http://lists.hosef.org/cgi-bin/mailman/listinfo/luau
[LUAU] Possbile TPOSSCON partnering
Has anyone seen if there is any synergy with these conferences? Pacific Telecommunications Council '05 http://www.ptc05.org/program/index.html SIP Summit at the Winter Pacific Telecommunications Council http://www.pulver.com/sipsummit2005/index.html -Matt
Re: [LUAU] Virtual directory points to another computer
On Thu, Dec 30, 2004 at 10:42:34AM -1000, Matt Darnell wrote: The applicatoin is to have a local FTP server but the data the user can upload/download would be located on another PC. The link between the two PC's should be encrypted. What platforms are involved? The responses so far imply *nix to *nix, making the encrypted copying problem easy (rsync/scp/sftp/SSH). -Vince
Re: [LUAU] Possbile TPOSSCON partnering
Matt Darnell wrote: Has anyone seen if there is any synergy with these conferences? Pacific Telecommunications Council '05 http://www.ptc05.org/program/index.html A little group called HOSEF is a sponsor http://www.ptc.org/PTC05/sponsor/sponsor_list.html in exchange for setting up and managing a Linux Thin Client Email Garden. Just *look* at those sponsors. For many, this will be their first exposure to Linux. We still need a few volunteers to help. This ia a *great* networking opportunity and is *huge* for the OSS community. Also, page 8 of the brochure http://www.ptc.org/PTC05/pdf/PTC05_Conf_Brochure_9.01.pdf Promotes TPOSSCON. We made this partnership with Sharon and the good folks at PTC back in September. You have hopefully noticed that we promote them on the TPOSSCON website. SIP Summit at the Winter Pacific Telecommunications Council http://www.pulver.com/sipsummit2005/index.html Nothing with this. -Matt --scott -- R. Scott Belford Founder/Director The Hawaii Open Source Education Foundation PO Box 392 Kailua, HI 96734 808.689.6518 phone/fax [EMAIL PROTECTED]
Re: [LUAU] Virtual directory points to another computer
On Thursday 2004-12-30 11:15, Matt Darnell wrote: Does anyone know how to have a 'symlink' that will point to a directory on another computer? NFS mount the remote computer's directory. Thanks for this. Would the link from the FTP server to the host 'file' server be encrypted? most NFS is not encrypted, so you need to encrypt the files to be shared. The files have some sensitive information that we would like to encrypted. Unfortunately the clients do not support secure FTP. Right now they are pulling the files from a remote FTP server and the sensitive data is beign sent over the line in plain text. We are trying to encrypt the 'public' portion of the FTP journey. One of the Linux magazines in the last couple months ran an article about how to wrap security around legacy unencrypted comms standards, like FTP. Probably Linux Magazine, Linux Journal, or Linux Format. -- All information and transactions are non negotiable and are private between the parties. All rights reserved without prejudice; Copyright 2004 Angela Kahealani. http://www.kahealani.com/
[LUAU] TPOSSCON Registration...or NOT?
Alle, I registered for TPOSSCON on the website and received my PAYPAL verification receipt. This was on the 17th of December. Does anyone know whether I should expect any other e-correspondence from the conference registration folks, or is the PAYPAL receipt my Welcome to TPOSSCON? Should I just bring a copy of my receipt to the registration desk in case there are any problems? Also, did the convention get any deals with local hotels for special room rates? I found nothing on the Where to stay section of the website regarding this. Best Regards, Camron Camron W. Fox Hilo Office High Performance Computing Group Fujitsu America, INC. E-mail: [EMAIL PROTECTED] Phone: (808) 934-4102 Cell: (808) 937-5026
Re: [LUAU] Virtual directory points to another computer
On Thu, Dec 30, 2004 at 04:05:57PM -1000, Matt Darnell wrote: One side is an Linksys WRTG54S - http://www.linksys.com/products/product.asp?grid=33scid=35prid=610 - running openwrt - http://openwrt.org/ the other side is a debian box. The files on the FTP server are too large to fit on the WRT so I don't think rsync would work. The files the client uploads/downloads would only be on the remote PC. I suppose you could NFS mount a larger filesystem from the Debian box to the Linksys, provided they are on the local LAN. You could then use GUI tools like WinSCP on the PC to drive the encrypted copy. If the two *nix boxes are not on the same LAN, then you are asking for remote filesystem over an encrypted tunnel. That, to put it technically, would really suck! In this particular case, you are probably better off moving from the Linksys to a Soekris or WRAP so you can get some real disk storage on the device. -Vince
Re: [LUAU] TPOSSCON Registration...or NOT?
Camron W. Fox wrote: Alle, I registered for TPOSSCON on the website and received my PAYPAL verification receipt. This was on the 17th of December. Does anyone know whether I should expect any other e-correspondence from the conference registration folks, or is the PAYPAL receipt my Welcome to TPOSSCON? Should I just bring a copy of my receipt to the registration desk in case there are any problems? A badge will be printed for you, so unless another Camron Fox shows up, with ID, and claims it, you will need only your drivers license. I suppose that at this point your receipt is your Welcome to TPOSSCON! greeting. Not very good, so I appreciate the feedback. I will work with the webmasters to improve this. Expect a letter from the organizers at the turn of the year. If you have any trouble when you arrive, ask for me. Also, did the convention get any deals with local hotels for special room rates? I found nothing on the Where to stay section of the website regarding this. Yes. Several Sheraton properties have offered special TPOSSCON rates http://www.tposscon.com/where_to_stay.php and Aloha Airlines is our official carrier. You can get 15% off of published rates by mentioning the conference. Our webmasters are working on getting this information up. You will need the registration code that I am mailing you privately. We are working on adding this to your registration email. The Aloha Airlines details are They will just need to call in to our reservations department at 484- (Oahu), Neighbor Islands 1-800-367-5250, U.S. Mainland and Canada 1-800-367-5250/1-877-879-2564 and advise the agent that they are attending the conference. The code is xxx. This promotional fare is valid from January 14, 2005 through January 31, 2005. Best Regards, Camron aloha --scott
[LUAU] SAMBA Workshop with John Terpstra
During TPOSSCON you will have the chance to hear John Terpstra discuss his global work to fight software patents. The prior Saturday and Monday, January 15 and January 17, Mr. Terpstra has agreed to hold an intense, two-day SAMBA workshop at the McKinley Community School for Adults for 20 people only. The classes will be help from 8-6. For $375 attendees will receive An autographed copy of his book, The Official Samba-3 HOWTO Reference Guide, ISBN: 0131453556 Lunch (pizza) 20 hours of intense focus A unique opportunity to spend time with a globally recognized master of perhaps the *most* critical windows replacing OSS application, SAMBA. Mr. Terpstra's other books are Samba-3 by Example, ISBN: 0131472216 Hardening Linux, ISBN: 0072254971 with more in production. You can reserve your spot now by writing Scott Belford, [EMAIL PROTECTED], and mentioning something about SAMBA in your subject. Your spot will be guaranteed by sending payment to our PO Box, or by paying online in the next day or two once our paypal link is created. You will be advised once it is ready. These spots will fill *very* fast, so please take advantage of this rare and worthy opportunity. --scott -- R. Scott Belford Founder/Director The Hawaii Open Source Education Foundation PO Box 392 Kailua, HI 96734 808.689.6518 phone/fax [EMAIL PROTECTED]
