Stress testing memory using malloc in linux ?? Post: 302380168

Sponsored Content

Top Forums Programming Stress testing memory using malloc in linux ?? Post 302380168 by Corona688 on Monday 14th of December 2009 12:22:59 PM

12-14-2009

Registered User

Quote:

Originally Posted by frozensmilz

Hi to all,

Recently i am testing an equipment that runs in i586 fedora linux. I have to test mmap function. For that i determined to fill the memory and run the required application to check whether it throws any mmap error regarding low resources.

This is the line that does the allocation.
p = (long double *) malloc(BUFFSIZE);

In windows process explorer i have noticed that what ever value we give it to BUFFSIZE it will increase the size of "Private Bytes" but not working set memory or actual memory. In linux the memory still remains the same even after allocating about 1000MB.

Linux will show memory that is malloced but never used in any way under its' virtual memory stat.

If you want the system to actually run out of memory, and not kill random processes to regain it, you may want to turn overcommit and oom-kill off on your linux system. With overcommit enabled, it will only allocate memory you actually use. I cannot predict the effects of this on a system completely lacking in swap memory however -- why does your system not have it? Was Windows tested under these conditions too?

Code:

echo 2 > /proc/sys/vm/overcommit_memory
echo 0 > /proc/sys/vm/oom-kill

These settings are not persistent. If you reboot the machine, they will be set back to default values. Which are frankly more stable for reasons you're discovering -- it makes it harder for endless memory leaks to kill your machine. Not all versions of linux have /proc/sys/vm/oom-kill, I'm hunting for the alternative. You may find it listed by sysctl -A.

Quote:

The "memset" package is not available and cannot be installed

What memset package? If you mean the C function, it definitely has memset. You need to include <string.h>.

Last edited by Corona688; 12-14-2009 at 01:48 PM..

Corona688

View Public Profile for Corona688

Visit Corona688's homepage!

Find all posts by Corona688

10 More Discussions You Might Find Interesting

1. Programming

malloc gives the same memory to two different nodes. How to deal with it?

When allocating memory for two different nodes, the resulting memory are the same. Clearly, this will lead to a mistake. This happened in a function. And the process must be in a function. (gdb) p tree->list $43 = (node *) 0x8be4180 (gdb) p tree->list $44 = (node *) 0x8be4180 At the...

2. Solaris

how to stress the memory

Hi All, Is there way to stress memory on Solaris 10? If yes, how do I monitor the memory usage?

3. UNIX and Linux Applications

Solaris & Linux memory stress test?

I'm looking for a script or some other application that will use up a lot of memory on a Solaris or Linux server, in order to test a monitoring application. So far I have found a script that's good for CPU usage but it does nothing for memory. I have also tried the application called 'stress'...

4. Programming

Why memory allocated through malloc should be freed ?

Actually for a process to run it needs text, stack , heap and data segments. All these find a place in the physical memory. Out of these 4 only heap does exist after the termination of the process that created it. I want to know the exact reason why this happens. Also why the other process need to...

5. Programming

Regarding the maximum memory allocated by malloc() function on HP-UX B11.11

In a 'C' program,when I am trying to allocate memory with the help of malloc () function, it is allocating the memory up to a certain limit for e.g. in my case, it is 670 MB (approx). malloc() returns NULL if I allocate more than this amount of memory.When I tried to allocate memory in chunks of...

6. Shell Programming and Scripting

Stress testing php files at Unix/Linux Command line

Hi, Your great help is very appreciated. I am looking for any Unix command or tool for doing Stress/Load test of php files at command prompt. I tried torture.pl but it is not working after20 concurrent threads/users. as it is very urgent for me..please suggest ur ideas asap. thanks

7. Programming

./match_pattern.out: malloc(): memory corruption: 0x0000000013a11600 ***

Hi All, I have a simple code which does some computation by matching string patterns. In brief: 1. The code reads .dat and .txt files. 2. .dat files are huge text files and .txt files contain some important words. 3. I am just doing strstr to find the patterns. 4. The function returns the...

8. Programming

glib detected: malloc() memory curruption

I am using libxml2 library for XMl parsing and libxml++ is C++ wrapper over that. So I am using API of libxml++. I am creating my class and composing instance xmlpp::Node *pNode in that. my class also have funciton prepareXPathQuery() which creates query string and have other fucntion...

9. Programming

* glibc detected * ./a.out malloc() memory corruption

I am facing a problem of memory corruption. The loop runs for the first time but does not go through the second time. What could be the problem? for(int z=0;z<2;z++) { fp=fopen("poly.dat","r"); /*do something which reads this file into a 2D array*/ fclose(fp); ...

10. UNIX for Beginners Questions & Answers

3rd party stress testing services

Hi all, bit of a forum newb here, so apologies if this has been covered else where, but I wonder if any of you has any experience with stress testing servers, specifically using 3rd party services. We run a very busy production system, and just haven't been able to simulate the user activity while...

LEARN ABOUT PLAN9

kill

KILL(1) 						      General Commands Manual							   KILL(1)

NAME

       kill, broke - print commands to kill processes

SYNOPSIS

       kill name

       broke

DESCRIPTION

       Kill  prints  commands  that  will cause all processes called name and owned by the current user to be terminated.  Use the send command of
       81/2(1), or pipe the output of kill into rc(1) to execute the commands.

       Kill suggests sending a kill note to the process; the same message delivered to the process's ctl file (see proc(3)) is a surer,  if  heavy
       handed, kill, but is necessary if the offending process is ignoring notes.

       Broke  prints  commands	that  will  cause all processes in the Broken state and owned by the current user to go away.  When a process dies
       because of an error caught by the system, it may linger in the Broken state to allow examination with a debugger.  Executing  the  commands
       printed by broke lets the system reclaim the resources used by the broken processes.

SOURCE

       /rc/bin/kill
       /rc/bin/broke

SEE ALSO

       ps(1), stop(1), proc(3)

																	   KILL(1)

10 More Discussions You Might Find Interesting

1. Programming

malloc gives the same memory to two different nodes. How to deal with it?

Discussion started by: cdbug

2. Solaris

how to stress the memory

Discussion started by: samnyc

3. UNIX and Linux Applications

Solaris & Linux memory stress test?

Discussion started by: Kraas

4. Programming

Why memory allocated through malloc should be freed ?

Discussion started by: karthiktceit