Re: ulimit strangeness

[jarausch@xxxxxxxxxxxxxxxxxxx]

On 15 Nov, Peter Stephenson wrote:
> "Bart Schaefer" wrote:
>> zsh% ulimit -v $[200*1024]; limit
>> cputime         unlimited
>> filesize        unlimited
>> datasize        unlimited
>> stacksize       8MB
>> coredumpsize    unlimited
>> memoryuse       unlimited
>> maxproc         2040
>> descriptors     1024
>> memorylocked    unlimited
>> addressspace    200kB		<-- Note, not 200 megabytes!
>>
>> It looks like this has something to do with the convoluted #ifdef that
>> prevents duplicate case labels in rlimits.c when both RLIMIT_RSS and
>> RLIMIT_VMEM are defined, but I haven't yet figured out what to fix.
> 
> My guess is the test `RLIMIT_RSS != RLIMIT_VMEM' is incorrectly failing
> in the preprocessor, i.e. it thinks RLIMIT_RSS == RLIMIT_VMEM owing to
> the way the definitions are laid out.  Checking
> /usr/include/sys/resource.h or carefully hidden equivalent should
> confirm or refute this.  The following programme might help.
> 
>   #include <stdio.h>
>   #include <sys/resource.h>
> 
>   int main(int argc, char **argv)
>   {
>   #if defined(RLIMIT_RSS) && defined(RLIMIT_VMEM)
>       printf("You have both definitions.\n");
>       if (RLIMIT_RSS == RLIMIT_VMEM)
>       {
> 	  printf("Both have the same value.\n");
>       }
>       else
>       {
> 	  printf("They have different values.\n");
>   #if RLIMIT_RSS == RLIMIT_VMEM
> 	  printf("!!!You should never see this message!!!\n");
>   #endif
>       }
>   #else
>   #ifdef RLIMIT_RSS
>       printf("You only have RSS\n");
>   #else
>   #ifdef RLIMIT_VMEM
>       printf("You only have VMEM\n");
>   #else
>       printf("You have neither definition.\n");
>   #endif
>   #endif
>   #endif
> 
>       return 0;
>   }
> 
> We could probe this more reliably than at present in configure.
> 

Here on my machine (Linux-From-Scratch   2.4.20-rc1 glibc 2.2.5) I get
You only have RSS.

Thanks,

Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
Aachen University
D 52056 Aachen, Germany