fixing heap_chunk_in_mb to 512MB doesn't work

fixing heap_chunk_in_mb to 512MB doesn't work

[Charles Werner]

Re: Cygwin memory limit

Recently I wanted to increase the program/data memory limit for cygwin 
beyond the default 256 MB
and a quick scan of the cygwin list revealed this thread. I was able to 
get this to work by doing the
following:

1. modify the registry, adding a DWORD value  heap_chunk_in_mb and 
setting it to 1024
using the regtool that is part of the cygtools package in cygwin. The 
value here is in decimal Mbytes:

regtool -i  set  /HKCU/Software/Cygnus\ 
Solutions/Cygwin/heap_chunk_in_mb 1024
regtool -v  list  /HKCU/Software/Cygnus\ Solutions/Cygwin

2. rebooting the machine
3. turning off the inetd service (if you have installed the cygwin inetd 
service)
4. restarting the inetd service
5. open a cygwin bash shell window.

I tested the memory allocation using the following little C program, 
compiled with:

gcc -O  max_mem.c -o max_mem.exe

#include "stdlib.h"
#include "stdio.h"

int main(int argc, char **argv)
{
  char *m;
  int mb;
  size_t n;
 
  if(argc < 2) {
    printf("usage: %s <Mb>\n\n",argv[0]) ;
    printf("input parameters: \n");
    printf("  MB            number of MB of memory to allocate\n");  
    exit(-1);
  }
  sscanf(argv[1],"%d",&n);
  m = malloc((size_t)n*1024*1024);
  if(m == NULL){fprintf(stderr,"cannot allocate memory %d MB of 
memory\n",n); exit(-1);}
  else printf("allocated %d MB of memory\n",n);
  free(m);
  return(0);
}

My system is an NT4 SP5 machine running the latest cygwin dll  version 
1.3.12. I also tried this on a win2K SP2 system
sucessfully.

Cheers,
Charles

-- 
Dr. Charles L. Werner
Gamma Remote Sensing AG
Thunstrasse 130
CH-3074 Muri b. Bern, Switzerland

http://www.gamma-rs.ch




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Re: fixing heap_chunk_in_mb to 512MB doesn't work

[Dylan Cuthbert]

Hello, can't help you but I had the same problem.  Sometimes Cygwin's
configuration sits in different parts of the registry, have a look in
LOCAL_MACHINE\Software\..etc..

If you have any luck, let me know, I just had to give up for the time-being.

Regards

---------------------------------
Q-Games, Dylan Cuthbert.
http://www.q-games.com
P2P internet radio - http://www.peercast.org

"Christophe Trophime" <trophime@grenoble.cnrs.fr> wrote in message
news:1031133455.17672.11.camel@SNCI-PC3-15.grenoble.cnrs.fr...
> As far as I have understood allocation is limited to 128 MB
> in cygwin 1.3.12 but one can increased this limit by setting
> heap_chunk_in_mb registry key.
>
> I tried to fix this value to 512 Mb using :
> regtool set '\user\Software\Cygnus Solutions\Cygwin\heap_chunk_in_mb'
> 512
>
> But when I compile this little test program it fails (Aborted (cored
> dumped)):
>
> #include <iostream>
> using namespace std;
>
> int main(){
>
>    char * tab_ptr = new char [256 * 1024 * 1024];
>    if ( !tab_ptr ) {
>        cerr << "Malloc failed\n";
>        exit(1);
>    }
>    delete tab_ptr;
>    return 0;
> }
>
> Thanks for your help
>
>
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>




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fixing heap_chunk_in_mb to 512MB doesn't work

[Christophe Trophime]

As far as I have understood allocation is limited to 128 MB
in cygwin 1.3.12 but one can increased this limit by setting
heap_chunk_in_mb registry key.

I tried to fix this value to 512 Mb using :
regtool set '\user\Software\Cygnus Solutions\Cygwin\heap_chunk_in_mb'
512

But when I compile this little test program it fails (Aborted (cored
dumped)):

#include <iostream>
using namespace std;

int main(){
   
   char * tab_ptr = new char [256 * 1024 * 1024];
   if ( !tab_ptr ) {
       cerr << "Malloc failed\n";
       exit(1);
   }
   delete tab_ptr;
   return 0;
}

Thanks for your help


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