Extremely poor performance crunching random numbers under PIV-FC5

BankHacker bankhacker at gmail.com
Fri May 19 00:11:34 UTC 2006


> It seems that maybe we can just say the whole problem comes down to that
> rand() from dynamically linked libc.so.6 is slower to execute than what
> is supposed to be the same code statically linked.

Yes, glibc is under suspicion. There are several indications ...


> If you can't get random_r() to work (see eg
> http://refspecs.freestandards.org/LSB_1.2.0/gLSB/baselib-random-r-3.html

I am trying to implement random_r function. This is my try:

### prueba.c #####################################################
	#include <stdio.h>
	#include <stdlib.h>

	int32_t r;
	struct random_data rand_data;

	int main(int argc, char ** argv) {
	    random_r(&rand_data, &r);
	    printf("%d\n", (int)r);

	    return (0);
	}
### prueba.c (the end) ###########################################


But I obtain this result:

	# gcc prueba.c -o prueba -Wall -pedantic
	# ./prueba
	Segmentation fault

I am doing something wrong. Any hint?

Thanks!




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