07-28-2010
Memory Leak
Hi,
I am trying a database server which keeps a B+ plus tree structure and works on it.
I am trying to find the memory used/leak while executing this process.
I check the memory leak by using ps uax command.
When i execute a delete query i am sure that my code frees up the existing allocation and adds a new allocation.
By doing this is, memory usage should not increase as per my understanding. Because the new allocation will always be less than the previous allocaiton.
But it shows increase in memory when check using ps uax.
Is it that when I call free function and that will not immediately return the memory chunk to free.
Or what is best way to check how many allocations have been made in a process and what size.
Please help me on this.
Regards
Kumaran
9 More Discussions You Might Find Interesting
1. Programming
Hi,
First of all I appreciate this group very much for its informative discussions and posts.
Here is my question.
I have one process whose virtual memory size increases linearly from 6MB to 12MB in 20 minutes. Does that mean my process has memory leaks?
In what cases does the... (4 Replies)
Discussion started by: shriashishpatil
4 Replies
2. UNIX for Advanced & Expert Users
I am running c++ code on AIX unix.I have a doubt that my code is using some memory but it is not clearing that.Some time i am getting heap allocation problem.In my code i am not using any malloc,new functions also i am justing using pointers and arrays.
Is there any way i can find out if the... (2 Replies)
Discussion started by: ukatru
2 Replies
3. UNIX for Advanced & Expert Users
I tried to execute a sample pthread program to cancel a newly created one using pthread_cancel(). but using valgrind on my code shows some memory leak.
My Code:
#include "iostream"
#include "unistd.h"
#include "pthread.h"
#include "signal.h"
using namespace std;
void handler(int);
void*... (4 Replies)
Discussion started by: kcr
4 Replies
4. Programming
I have this code...
#include <stdio.h>
#include <iostream>
#include <pthread.h>
static void* cliente(void *datos);
int main()
{
pthread_attr_t tattr;
int ret;
size_t size = PTHREAD_STACK_MIN + 0x0100;
ret = pthread_attr_init(&tattr);
ret =... (8 Replies)
Discussion started by: JEscola
8 Replies
5. UNIX for Advanced & Expert Users
Hi.
This might be a strange request, but does anyone have any idea on a simple shell script that would use more and more memory as it ran? Like a purposeful leak.
I want to test the behaviour of an already running program when the machine runs out of memory.
Thanks! (4 Replies)
Discussion started by: rebelbuttmunch
4 Replies
6. IP Networking
Hi All,
my client server application can work in two modes:
1) one direction - only client sends msgs to server
2) two directions - server gives 'answers' to client.
when program run in the first mode it looks OK, but when server answers to client than client's application exit its... (2 Replies)
Discussion started by: lenna
2 Replies
7. Programming
hi all
Can any one plz explain me about memory leak problem
Thankx (5 Replies)
Discussion started by: sonali
5 Replies
8. Red Hat
Hi all
I am using RED HAT 5.4, and i am getting memory uses problem. when i use "sync;echo 3 > /proc/sys/vm/drop_cache" command the memory will release after 2,3 hour memory show 95%.
pls suggest right way.
thanks (37 Replies)
Discussion started by: reply.ravi
37 Replies
9. Programming
I have written this code in C which reads a very large collection of text files and does some processing. The problem with this code is that there are memory leaks which I am not able to figure out as to where the problem is. When I run this code, and see the memory usage using top command, then I... (7 Replies)
Discussion started by: shoaibjameel123
7 Replies
LEARN ABOUT DEBIAN
bup-margin
bup-margin(1) General Commands Manual bup-margin(1)
NAME
bup-margin - figure out your deduplication safety margin
SYNOPSIS
bup margin [options...]
DESCRIPTION
bup margin iterates through all objects in your bup repository, calculating the largest number of prefix bits shared between any two
entries. This number, n, identifies the longest subset of SHA-1 you could use and still encounter a collision between your object ids.
For example, one system that was tested had a collection of 11 million objects (70 GB), and bup margin returned 45. That means a 46-bit
hash would be sufficient to avoid all collisions among that set of objects; each object in that repository could be uniquely identified by
its first 46 bits.
The number of bits needed seems to increase by about 1 or 2 for every doubling of the number of objects. Since SHA-1 hashes have 160 bits,
that leaves 115 bits of margin. Of course, because SHA-1 hashes are essentially random, it's theoretically possible to use many more bits
with far fewer objects.
If you're paranoid about the possibility of SHA-1 collisions, you can monitor your repository by running bup margin occasionally to see if
you're getting dangerously close to 160 bits.
OPTIONS
--predict
Guess the offset into each index file where a particular object will appear, and report the maximum deviation of the correct answer
from the guess. This is potentially useful for tuning an interpolation search algorithm.
--ignore-midx
don't use .midx files, use only .idx files. This is only really useful when used with --predict.
EXAMPLE
$ bup margin
Reading indexes: 100.00% (1612581/1612581), done.
40
40 matching prefix bits
1.94 bits per doubling
120 bits (61.86 doublings) remaining
4.19338e+18 times larger is possible
Everyone on earth could have 625878182 data sets
like yours, all in one repository, and we would
expect 1 object collision.
$ bup margin --predict
PackIdxList: using 1 index.
Reading indexes: 100.00% (1612581/1612581), done.
915 of 1612581 (0.057%)
SEE ALSO
bup-midx(1), bup-save(1)
BUP
Part of the bup(1) suite.
AUTHORS
Avery Pennarun <apenwarr@gmail.com>.
Bup unknown- bup-margin(1)