Failure to build libjava on 512MB machine

Thu Feb 1 21:19:00 GMT 2007

On 2007年1月31日, Andrew Haley wrote:
> Can you tell us a bit more about the config? It really shouldn't be
> failing to compile this program.

The tester where this problem first surfaced as a 32-bit Athlon machine,
with 512MB main memory and 1GB swap. The machine runs FreeBSD 5.4.
I agree with your intuition that even if the machines is swapping heavily, 
this amount of virtual memory (1.5GB) should suffice.
However, a bit of investigations makes me believe that, at least in the 
default configuration, FreeBSD 5.4 will refuse to allocate more memory to 
a single process than the system has main memory.
At least this is what the output of the following quick test program I
hacked indicates:
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #define MB 1024*1024
 main() {
 for(int i=1; i <= 600; i++) {
 printf("%dMB ",i); fflush(stdout);
 char *p=(char*)malloc(MB);
 if( p == NULL ) {
 printf("\nCrap!\n");
 return 1;
 }
 }
 }
After 512MB, the output I get is
 510MB
 511MB
 512MB
 Crap!
while, at the same time, a GCC bootstrap is nicely proceeding on the
same machine. I do not know how many other system may behave similarly,
but at least this explains my (unexpected) bootstrap failures.
Gerald