Search code examples
clinuxgcc

How to allow more memory and avoid stack overflow on lots of recursion?

I'm testing the timing of an algorithm that does lots of recursive calls. My program dies at about 128k recursive calls, and this takes only .05 seconds. I'd like to allow more memory to have longer timings in my analysis. I'm running linux and using gcc. Is there a system call, or environment variable, or gcc flag, or wrapper, or something?

Solution

  • There is no stack size complier option for gcc under Linux. However this text discusses how to set the stack size on Linux. using the ulimit command.

    Edit: That link died in Dec 2023 so here are the contents, as retrieved by the Wayback Machine:

    Stack Overflow Problems

    This file gives some hints on addressing this problem on different platforms.

    Under Unix-like systems, programs may throw a "Segmentation Fault" error. This can be due to stack overflow, especially from recursive function calls or huge data sets. In our demo program "Pi" (see "$(CORE_PATH)/progs/pi"), we compute Pi to any number of desired bits or digits.

    Here are some test results on when stack overflows will occur on different platforms, using their default stack sizes.

    platform default size # bits # digits
    SunOS/Solaris 8172K bytes <=39875 <=12003 (Shared Version)
    Linux 8172K bytes <=62407 <=18786
    Windows 1024K bytes <=10581 <=3185 (Release Version)
    cygwin 2048K bytes <=3630 <=1092

    If we now change their stack size to their maximum, our Pi program can compute more bits.

    platform stack size # bits # digits
    SunOS/Solaris unlimited >=100,000 30102
    Linux 8172K bytes <=33,219,282 <=10,000,000(?)
    Windows 32768K bytes <=343077 <=12041

    How to change the default stack size on different platforms

    In general, under Unix-like platforms, the stack size is controlled by environment variable, not the program itself.
    So you cannot pass any flags to the compilers, like gcc, to setup stack size.
    Under Windows platforms, the stack size information is contained in the executable files. It can be set during compilation in Visual C++, but this is not available in gcc.
    Alternatively, Microsoft provides a program "editbin.exe" which can change the executable files directly. Here are more details:

    SunOS/Solaris:

    limit # shows the current stack size
    unlimit # changes the stack size to unlimited
    setenv STACKSIZE 32768 # limits the stack size to 32M bytes

    Linux:

    ulimit -a # shows the current stack size
    ulimit -s 32768 # sets the stack size to 32M bytes

    Windows (during compilation):

    1. Select "Project->Setting".
    2. Select "Link" page.
    3. Select "Category" to "Output".
    4. Type your preferred stack size in "Reserve:" field under "Stack allocations". eg, 32768 in decimal or 0x20000 in hexadecimal.

    Windows (to modify the executable file):

    There are two programs included in Microsoft Visual Studio, "dumpbin.exe" and "editbin.exe".
    Run dumpbin /headers executable_file and you can see the "size of stack reserve" information in "optional header values".
    Run editbin /STACK:size to change the default stack size.