"softlimit -m" also limits the maximum virtual address space (i.e. it calls setrlimit(2) on the resource RLIMIT_AS1) — see the man page for details).   So what you're testing here is the virtual memory usage.

The virtual memory usage of a program, however, is not necessarily a useful measure of how much memory a program actually currently "needs".  It's more a measure of the address space that the program can potentially address (without allocating more), not of how much physical memory it actually has in use — the resident set size (RSS) is a better measure of the latter.   In other words, I wouldn't be worried too much :)

For comparison, my 64-bit Perl 5.12.4 on Ubuntu uses: 

$ perl -le 'use version; print $version::VERSION; system "ps -p $$ -o 
+rss,vsz,comm"'
0.82
  RSS    VSZ COMMAND
 2476  24236 perl

[download]

___

1) 

$ strace -esetrlimit softlimit -m 25000000 perl -e1
setrlimit(RLIMIT_DATA, {rlim_cur=25000000, rlim_max=RLIM_INFINITY}) = 
+0
setrlimit(RLIMIT_STACK, {rlim_cur=25000000, rlim_max=RLIM_INFINITY}) =
+ 0
setrlimit(RLIMIT_MEMLOCK, {rlim_cur=64*1024, rlim_max=64*1024}) = 0
setrlimit(RLIMIT_AS, {rlim_cur=25000000, rlim_max=RLIM_INFINITY}) = 0

[download]

In reply to Re: memory usage on x86_64 by Eliya
in thread memory usage on x86_64 by powerman

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