Re: 6.5.5 much slower than 6.3.6

Hello duc,

Here are test results from both systems - slow and fast.

slow system:

w11# time ./a.out
489654080
0.110u 0.132s 0:00.24 100.0%    17+199k 0+0io 0pf+0w

fast system:

w14# time ./a.out
1867392448
0.157u 0.105s 0:00.26 96.1%     5+184k 0+0io 0pf+0w



Since, the timing is almost identical, I think, that getpid here is
really not the problem.

What I am trying to figure out, is why I have many getpid lines in the strace
of the simple "strace convert" command (which is identical to --help)
on the slow system and not on the fast one?







Monday, September 28, 2009, 8:28:02 PM, you wrote:

> In ImageMagick, getpid() is called once when getting the execution
> path and call multiple times when gathering entropy for random number
> generation and when logging.  Even so, getpid() is lightweight.  How long
> does this program take on your system:

>   #include <stdio.h>
>   
>   main()
>   {
>     int i,j = 0;
>     for (i=0; i < 1000000; i++)
>       j+=getpid();
>     printf("%d\n",j);
>   }
>   
>   cc gif.c
>   time a.out
>   -989967296
>   0.004u 0.001s 0:00.01 0.0%      0+0k 8+0io 0pf+0w
>   
> On our system, 1 million calls to getpid() consumes less than 0.01 seconds
> of elapsed time suggesting getpid() is not the cause of any apparent slowdown
> of ImageMagick.



Arkadiy Kulev                         mailto:[email protected]
+7 495 5070602
Moscow, Russia