calloc speed difference

Marco Atzeri marco.atzeri@gmail.com
Fri Jan 12 09:07:00 GMT 2018


On 12/01/2018 08:19, Lee wrote:
> Why is the cygwin gcc calloc so much slower than the
> i686-w64-mingw32-gcc calloc?
>    1:12 vs 0:11
> 
> $cat calloc-test.c
> #include <stdio.h>
> #include <stdlib.h>
> #define ALLOCATION_SIZE (100 * 1024 * 1024)
> int main (int argc, char *argv[]) {
>      for (int i = 0; i < 10000; i++) {
>          void *temp = calloc(ALLOCATION_SIZE, 1);
>          if ( temp == NULL ) {
>             printf("drat! calloc returned NULL\n");
>             return 1;
>          }
>          free(temp);
>      }
>      return 0;
> }
> 
> $gcc calloc-test.c
> $time ./a
> 
> real    1m12.459s
> user    0m0.640s
> sys     1m11.750s

it seems a local problem, maybe BLODA?

I have roughly the same for both 32 and 64 cygwin version on W7-64

$ time ./calloc-tests

real    0m8.346s
user    0m0.904s
sys     0m7.175s


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