Sponsored Content
Full Discussion: memcpy error
Top Forums Programming memcpy error Post 302567639 by DreamWarrior on Monday 24th of October 2011 02:39:44 PM
Old 10-24-2011
Quote:
Originally Posted by achenle
Hmm, I wonder what happens if you try to read a few GB from a SAN-based file system built on 4 or 6 or maybe more parallel LUNs configured by someone who knows how to lay out storage, and attached with 8 gbps fiber?

Do you really think the VM manager in your kernel can keep up with data coming in that fast?

Guess what? It can't.

Heck, I've seen well-designed 2 gbps SANs with just a few LUNs overwhelm VM managers.

In other words, YES, there ARE reasons to memset() a chunk of RAM *before* you use it.

And that's not even addressing the default Linux method of allowing oversubscription of virtual mamory in the hope that it won't all be used. If reliability and deterministic behavoir are important to you, you don't rely on hope and things like the Linux OOM killer are crazy-bad.
I'm not sure what you're getting at here.... Are you saying the reason to call memset is to assist the VMM in keeping up with a fast transfer?
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Error: Internal system error: Unable to initialize standard output file

Hey guys, need some help. Running AIX Version 5.2 and one of our cron jobs is writing errors to a log file. Any ideas on the following error message. Error: Internal system error: Unable to initialize standard output file I'm guessing more info might be needed, so let me know. Thanks (2 Replies)
Discussion started by: firkus
2 Replies

2. Programming

memcpy segfaults, but not in windows

Hi Having a lil trouble with a rather simple application I'm writing. It so happens that I have to copy some data using memcpy() and so far I've been doing just fine compiling it with VC.Net and running it on Windows XP. Now I'm trying to port the thing to Solaris (which shouldn't really be too... (3 Replies)
Discussion started by: khoma
3 Replies

3. UNIX for Dummies Questions & Answers

awk Shell Script error : "Syntax Error : `Split' unexpected

hi there i write one awk script file in shell programing the code is related to dd/mm/yy to month, day year format but i get an error please can anybody help me out in this problem ?????? i give my code here including error awk ` # date-month -- convert mm/dd/yy to month day,... (2 Replies)
Discussion started by: Herry
2 Replies

4. Programming

Problem with memcpy

Hi , I am having records in a file like 00412772784705041008FRUITFUL STRWBRRY 00412772784703041008FRUITFUL STRWBERE 00000570632801448078 X i have declared a structure like typedef struct { char Uname; char Pname; ... (4 Replies)
Discussion started by: arunkumar_mca
4 Replies

5. AIX

nim mksysb error :/usr/bin/savevg[33]: 1016,07: syntax error

-------------------------------------------------------------------------------- Hello, help me please. I am trying to create a mksysb bakup using nim. I am geting this error, how to correct it ? : Command : failed stdout: yes stderr: no... (9 Replies)
Discussion started by: astjen
9 Replies

6. Programming

Segmentation Fault by memcpy

Hello everybody, I'm coding a test program for ARP protocol, and i don't know why i'm getting a SIGSEGV, i traced it with gdb and it says it's due to the memcpy function from /lib/libc.so.6. Program received signal SIGSEGV, Segmentation fault. 0xb7e9e327 in memcpy () from /lib/libc.so.6 This... (5 Replies)
Discussion started by: Zykl0n-B
5 Replies

7. UNIX for Dummies Questions & Answers

> 5 ")syntax error: operand expected (error token is " error

im kinda new to shell scripting so i need some help i try to run this script and get the error code > 5 ")syntax error: operand expected (error token is " the code for the script is #!/bin/sh # # script to see if the given value is correct # # Define errors ER_AF=86 # Var is... (4 Replies)
Discussion started by: metal005
4 Replies

8. Solaris

Rpcinfo: can't contact portmapper: RPC: Authentication error; why = Failed (unspecified error)

I have two servers with a fresh install of Solaris 11, and having problems when doing rpcinfo between them. There is no firewall involved, so everything should theoretically be getting through. Does anyone have any ideas? I did a lot of Google searches, and haven't found a working solution yet. ... (2 Replies)
Discussion started by: christr
2 Replies

9. Shell Programming and Scripting

Undefined reference to memcpy@GLIBC_2.14

Dear All, I am trying to compile OpenFOAM-1.7.x in RHEL. I could not able to compile some of the applications because of libc version issues. It is saying undefined reference to memcpy@GLIBC_2.14 Can anybody look into it? Thanks & Regards, linuxUser_ (3 Replies)
Discussion started by: linuxUser_
3 Replies

10. UNIX for Beginners Questions & Answers

Print Error in Console and both Error & Output in Log file - UNIX

I am writing a shell script with 2 run time arguments. During the execution if i got any error, then it needs to redirected to a error file and in console. Also both error and output to be redirected to a log file. But i am facing the below error. #! /bin/sh errExit () { errMsg=`cat... (1 Reply)
Discussion started by: sarathy_a35
1 Replies
MEMSET(3P)						     POSIX Programmer's Manual							MEMSET(3P)

PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
memset - set bytes in memory SYNOPSIS
#include <string.h> void *memset(void *s, int c, size_t n); DESCRIPTION
The memset() function shall copy c (converted to an unsigned char) into each of the first n bytes of the object pointed to by s. RETURN VALUE
The memset() function shall return s; no return value is reserved to indicate an error. ERRORS
No errors are defined. The following sections are informative. EXAMPLES
None. APPLICATION USAGE
None. RATIONALE
None. FUTURE DIRECTIONS
None. SEE ALSO
The Base Definitions volume of IEEE Std 1003.1-2001, <string.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html . IEEE
/The Open Group 2003 MEMSET(3P)
All times are GMT -4. The time now is 04:49 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy