1) Create and enable the Loadleveler submit filter
2) Create a suid wrapper to allow global use of the 'schedctl
-r' command
Step 1) Create a submit filter.
The LL submit filter functions by taking a users job command file as STDIN and sending the command file LL should process to STDOUT. If the submit filter is successful, it should exit with a status of 0. A simple sample script is provided below:
-----------
#!/bin/perl -w
while (<STDIN>)
{
$line = $_;
print STDOUT $line;
}
# Call wakeup script to maui scheduler
system("/usr/local/sbin/wakeup > /dev/null");
exit(0);
------------
1) create file 'wakeup.c'
To enable use of this script you must set SUBMITFILTER parameter
in the LoadL_config file.
Step 2) Create wrapper
The maui command 'schedctl' is not normally available to general end users. The wrapper allows users to issue a command to request that scheduling resume to process a newly submitted job.
wakeup.c
-----
#include <sys/types.h>
#include <pwd.h>
#define MAUIADMIN "loadl"
#define SCHEDCTLCMD /usr/local/bin/schedctl
void main()
{
struct passwd *buf;
if ((buf = getpwnam(MAUIADMIN)) == NULL)
exit(1);
setuid(buf->pw_uid);
system("SCHEDCTLCMD -r 1");
exit(0);
}
-----
2) edit 'MAUIADMIN' and 'SCHEDCTLCMD' #defines in 'wakeup.c' as needed
3) compile code
4) make 'wakeup' owned by MAUIADMIN
> chown loadl wakeup
5) make 'wakeup' setuid for owner
> chmod 4711 wakeup
6) verify non-admin users can successfully run 'wakeup'
Now submit a job. If all works correctly,
Maui should detect and, if resources are available, start the job within
one second.