Messages in this thread | | | From | Tung-Han Hsieh <> | Date | Mon, 28 Jul 2003 14:44:28 +0800 | Subject | malloc problem to allocate very large blocks |
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Hello,
I am developing applications which requires more than 2GB memory. But I found that in my Linux system the malloc() cannot allocate more than 2GB memory. Here is the details of my system:
CPU: Pentium 4 2.53 GHz RAM: 2 GB Swap: 512 MB OS: Debian-3.0 stable Kernel: 2.4.20 gcc: 2.95.4 20011002 glibc: 2.2.5-6
In theory, in a 32-bits machine the maximum allocatable memory is up to 4GB. But in the following very simple testing program:
===================================================================== #include <stdio.h> #include <stdlib.h>
main() { size_t l; char *s1=NULL, *s2=NULL;
l = 1024*1024*1024;
s1 = malloc(l); s2 = malloc(l); if (! s1) printf("s1 malloc failed\n"); if (! s2) printf("s2 malloc failed\n"); } =====================================================================
only the block for s1 can be allocated. Further, if I change the program to
===================================================================== #include <stdio.h> #include <stdlib.h>
main() { size_t l; char *s1=NULL;
l = 2*1024*1024*1024;
s1 = malloc(l); if (! s1) printf("s1 malloc failed\n"); } =====================================================================
the gcc complier complain to me that "foo.c:9: warning: integer overflow in expression" during the compilation (I use: "gcc foo.c" to compile it), and the block for s1 cannot be allocated at all. I am wondering if there is any way to overcome the 2GB limit.
Thank you very much for your reply in advance.
Best Regards,
T.H.Hsieh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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