hi,
i am running a very big code on my pc using redhat linux.
when i try to increase my array size, compile and run, i get
segmentation fault. i go into the debugger, run it, it crashes
right away. i can't even trace where it happens.
i have no idea what is the problem. any idea ???
11  2228  tw*********@yah oo.com (mike) writes: i am running a very big code on my pc using redhat linux.
when i try to increase my array size, compile and run, i get
segmentation fault. i go into the debugger, run it, it crashes
right away. i can't even trace where it happens.
i have no idea what is the problem. any idea ???
You probably screwed up memory allocation or access. Try a
memory debugger like valgrind.
--
int main(void){char p[]="ABCDEFGHIJKLM NOPQRSTUVWXYZab cdefghijklmnopq rstuvwxyz.\
\n",*q="kl BIcNBFr.NKEzjwC IxNJC";int i=sizeof p/2;char *strchr();int putchar(\
);while(*q){i+= strchr(p,*q++)-p;if(i>=(int)si zeof p)i-=sizeof p-1;putchar(p[i]\
);}return 0;}
"mike" <tw*********@ya hoo.com> wrote in message
news:58******** *************** ***@posting.goo gle.com... hi,
i am running a very big code on my pc using redhat linux.
when i try to increase my array size, compile and run, i get
segmentation fault. i go into the debugger, run it, it crashes
right away. i can't even trace where it happens.
i have no idea what is the problem. any idea ???
If you are unable to trace, you have probably corrupted your stack
by using an array with automatic storage duration that is too large.
What is the size of your array? Under c89 the size of the largest object
that can be created is 32767 bytes and 65535 bytes under c99.
--
j
"j" <ja**********@b ellsouth.net> writes: "mike" <tw*********@ya hoo.com> wrote in message
news:58******** *************** ***@posting.goo gle.com... i am running a very big code on my pc using redhat linux.
when i try to increase my array size, compile and run, i get
segmentation fault. i go into the debugger, run it, it crashes
right away. i can't even trace where it happens.
i have no idea what is the problem. any idea ???
If you are unable to trace, you have probably corrupted your stack
by using an array with automatic storage duration that is too large.
What is the size of your array? Under c89 the size of the largest object
that can be created is 32767 bytes and 65535 bytes under c99.
Those are minimum maxima. A C89 implementation is allowed to limit
object sizes to 32767 bytes, but it can supporter larger objects (and
most implementations do); likewise for C99 and 65535.
Some operating systems may provide ways to adjust memory allocation
limits. There may also be different limits for declared objects
vs. heap-allocated objects.
(Since this is comp.lang.c, not comp.unix.progr ammer, it would be
inappropriate to mention the "limit" or "ulimit" command, so I won't.)
--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.
mike wrote: I am running a very big code on my pc using RedHat Linux.
When I try to increase my array size, compile and run, I get
segmentation fault. I go into the debugger, run it, it crashes
right away. I can't even trace where it happens.
I have no idea what is the problem. Any idea?
cat main.c
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char* argv[]) {
char a[16*1024*1024];
const
size_t n = 16*1024*1024;
for (size_t j = 0; j < n; ++j)
a[j] = '\0';
fprintf(stdout, "Hello world!\n");
return 0;
}
gcc -Wall -std=c99 -pedantic -o main main.c
./main
Segmentation fault (core dumped) rm core.30147
limit stacksize
stacksize 10240 kbytes limit stacksize 20240
limit stacksize
stacksize 20240 kbytes
Hello world! gcc --version
gcc (GCC) 3.3.3 20040412 (Red Hat Linux 3.3.3-7)
E. Robert Tisdale wrote: mike wrote:
I am running a very big code on my pc using RedHat Linux.
When I try to increase my array size, compile and run, I get
segmentation fault. I go into the debugger, run it, it crashes
right away. I can't even trace where it happens.
I have no idea what is the problem. Any idea?
> cat main.c
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char* argv[]) {
char a[16*1024*1024];
const
size_t n = 16*1024*1024;
for (size_t j = 0; j < n; ++j)
a[j] = '\0';
fprintf(stdout, "Hello world!\n");
return 0;
}
> gcc -Wall -std=c99 -pedantic -o main main.c
> ./main
Segmentation fault (core dumped) > rm core.30147
> limit stacksize
stacksize 10240 kbytes > limit stacksize 20240
> limit stacksize
stacksize 20240 kbytes
./main
Hello world! > gcc --version
gcc (GCC) 3.3.3 20040412 (Red Hat Linux 3.3.3-7)
"Keith Thompson" <ks***@mib.or g> wrote in message
news:ln******** ****@nuthaus.mi b.org... "j" <ja**********@b ellsouth.net> writes: "mike" <tw*********@ya hoo.com> wrote in message
news:58******** *************** ***@posting.goo gle.com... i am running a very big code on my pc using redhat linux.
when i try to increase my array size, compile and run, i get
segmentation fault. i go into the debugger, run it, it crashes
right away. i can't even trace where it happens.
i have no idea what is the problem. any idea ???
If you are unable to trace, you have probably corrupted your stack
by using an array with automatic storage duration that is too large.
What is the size of your array? Under c89 the size of the largest object
that can be created is 32767 bytes and 65535 bytes under c99.
Those are minimum maxima. A C89 implementation is allowed to limit
object sizes to 32767 bytes, but it can supporter larger objects (and
most implementations do); likewise for C99 and 65535.
Sorry. I meant to include the word ``portably'' after ``created''.
Some operating systems may provide ways to adjust memory allocation
limits. There may also be different limits for declared objects
vs. heap-allocated objects.
(Since this is comp.lang.c, not comp.unix.progr ammer, it would be
inappropriate to mention the "limit" or "ulimit" command, so I won't.)
--
Keith Thompson (The_Other_Keit h) ks***@mib.org
<http://www.ghoti.net/~kst> San Diego Supercomputer Center <*>
<http://users.sdsc.edu/~kst> We must do something. This is something. Therefore, we must do this.
"j" <ja**********@b ellsouth.net> wrote in message news:<Zw******* ************@bi gnews6.bellsout h.net>... "mike" <tw*********@ya hoo.com> wrote in message
news:58******** *************** ***@posting.goo gle.com... hi,
i am running a very big code on my pc using redhat linux.
when i try to increase my array size, compile and run, i get
segmentation fault. i go into the debugger, run it, it crashes
right away. i can't even trace where it happens.
i have no idea what is the problem. any idea ???
If you are unable to trace, you have probably corrupted your stack
by using an array with automatic storage duration that is too large.
What is the size of your array? Under c89 the size of the largest object
that can be created is 32767 bytes and 65535 bytes under c99.
i use C programming to do simulations (solving eqns), so my knowledge of
the language is limited to what my needs are. i needed to mention this so
that you guys don't talk pass me.
ok...i declare all my variables with static array sizes. (a while back,
i did try the dynamic allocations as Emmanuel suggested below, but since there
is a huge number of variables with O(1e5-1e6) degrees of freedom with
complicate relationships, i decided to abandon this). one of my variables:
double q[2650000][10][5] -> this is fine, but when i try:
double q[4530000][10][5] -> here is the error i got from the ddd debugger:
Program received signal SIGSEGV, Segmentation fault.
0x40000be0 in q ()
you guys are right, it looks like the memory is messed up.
so there is a limit on the array size?
"j" <ja**********@b ellsouth.net> wrote in message news:<Zw******* ************@bi gnews6.bellsout h.net>... "mike" <tw*********@ya hoo.com> wrote in message
news:58******** *************** ***@posting.goo gle.com... hi,
i am running a very big code on my pc using redhat linux.
when i try to increase my array size, compile and run, i get
segmentation fault. i go into the debugger, run it, it crashes
right away. i can't even trace where it happens.
i have no idea what is the problem. any idea ???
If you are unable to trace, you have probably corrupted your stack
by using an array with automatic storage duration that is too large.
What is the size of your array? Under c89 the size of the largest object
that can be created is 32767 bytes and 65535 bytes under c99.
i use C programming to do simulations (solving eqns), so my knowledge of
the language is limited to what my needs are. i needed to mention this so
that you guys don't talk pass me.
ok...i declare all my variables with static array sizes. (a while back,
i did try the dynamic allocations as Emmanuel suggested below, but since there
is a huge number of variables with O(1e5-1e6) degrees of freedom with
complicate relationships, i decided to abandon this). one of my variables:
double q[2650000][10][5] -> this is fine, but when i try:
double q[4530000][10][5] -> here is the error i got from the ddd debugger:
Program received signal SIGSEGV, Segmentation fault.
0x40000be0 in q ()
you guys are right, it looks like the memory is messed up.
so there is a limit on the array size? This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics | |
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