Nice level for cron jobs

web-lib-funcs.pl

@@ -2570,10 +2570,21 @@ else {
 	}
 
 # Set the umask based on config
-if ($gconfig{'umask'}) {
+if ($gconfig{'umask'} && !$main::umask_already++) {
 	umask(oct($gconfig{'umask'}));
 	}
 
+# If this is a cron job or other background task, set the nice level
+if (!$main::nice_already && !$ENV{'SCRIPT_NAME'} && $gconfig{'nice'} &&
+    $gconfig{'os_type'} ne 'windows') {
+	# Cron jobs have no tty
+	if (!open(TTY, ">/dev/tty")) {
+		eval 'use POSIX; POSIX::nice($gconfig{\'nice\'});';
+		}
+	close(TTY);
+	}
+$main::nice_already++;
+
 # Get the username
 local $u = $ENV{'BASE_REMOTE_USER'} ? $ENV{'BASE_REMOTE_USER'}
 				    : $ENV{'REMOTE_USER'};

webmin/CHANGELOG

@@ -70,3 +70,4 @@ Added a field to the Advanced Options page to control the number of days that fi
 The format for dates displayed by Webmin can be changed by a new option on the User Interface page.
 ---- Changes since 1.380 ----
 Inheritance of the system path into Webmin's search path can be set on the Operating System and Environment page.
+The nice level (CPU priority) of all cron and other background jobs run by Webmin can now be set on the Advanced Options page.

webmin/change_advanced.cgi

@@ -51,6 +51,14 @@ else {
 	$gconfig{'umask'} = $in{'umask'};
 	}
 
+# Save nice level
+if ($in{'nice_def'}) {
+	delete($gconfig{'nice'});
+	}
+else {
+	$gconfig{'nice'} = $in{'nice'};
+	}
+
 &lock_file("$config_directory/config");
 &write_file("$config_directory/config", \%gconfig);
 &unlock_file("$config_directory/config");

webmin/edit_advanced.cgi

@@ -62,6 +62,16 @@ print &ui_table_row($text{'advanced_pass'},
 print &ui_table_row($text{'advanced_umask'},
 	    &ui_opt_textbox("umask", $gconfig{'umask'}, 5, $text{'default'}));
 
+# Nice level for cron jobs
+if (&foreign_check("proc")) {
+	&foreign_require("proc", "proc-lib.pl");
+	print &ui_table_row($text{'advanced_nice'},
+	    &ui_radio("nice_def", $gconfig{'nice'} eq '' ? 1 : 0,
+	      [ [ 1, $text{'default'} ],
+		[ 0, $text{'advanced_pri'}." ".
+		     &proc::nice_selector("nice", $gconfig{'nice'} || 0) ] ]));
+	}
+
 print &ui_table_end();
 print &ui_form_end([ [ "save", $text{'save'} ] ]);
 

webmin/lang/en

@@ -745,6 +745,8 @@ advanced_showstderr=Show Perl errors in browser?
 advanced_umask=Umask (unset permission bits) for created files
 advanced_eumask=Umask must be a 3-digit octal number
 advanced_etempdelete=Missing or invalid maximum age of temporary files
+advanced_nice=CPU priority for scheduled jobs
+advanced_pri=Priority level
 
 syslog_errorlog=Webmin error log