Fix to query specific fields in FreeBSD memory stats collection

*Note: Replace `sysctl -a` with targeted queries for only the 5 needed values (hw.physmem, hw.pagesize, vm.stats.vm.v_*_count) instead of dumping thousands of kernel params. This reduces `get_memory_info()` overhead from 25% CPU to ~5% CPU when called by real-time monitoring every 1-3 seconds.

CHANGELOG.md

@@ -6,6 +6,7 @@
 * Fix the printing of the bottom button row in the form column table
 * Fix to recommend Perl `Sys::Syslog` module #2557
 * Fix to avoid using short hostname in HTTPS redirects when an FQDN is available
+* Fix to query specific fields in FreeBSD memory stats collection, cutting CPU use by 80%
 * Add a complete overhaul of `var_dump` subroutine, which is now fully portable
 * Update the Authentic theme to the latest version with various fixes:
   - Fix the text color when reading email in the Read User Mail module [webmin#2555](https://github.com/webmin/webmin/issues/2555)

proc/freebsd-lib.pl

@@ -101,7 +101,16 @@ ioctl($ttyfh, 536900705, 0);
 sub get_memory_info
 {
 my $sysctl = {};
-my $sysctl_output = &backquote_command("/sbin/sysctl -a 2>/dev/null");
+# Get only the specific values we need not all with -a
+my @needed = qw(
+	hw.physmem
+	hw.pagesize
+	vm.stats.vm.v_inactive_count
+	vm.stats.vm.v_cache_count
+	vm.stats.vm.v_free_count
+	);
+my $sysctl_output = &backquote_command("/sbin/sysctl " .
+	join(" ", @needed) . " 2>/dev/null");
 return ( ) if ($?);
 foreach my $line (split(/\n/, $sysctl_output)) {
 	if ($line =~ m/^([^:]+):\s+(.+)\s*$/s) {