IQS(Apr 15, 1997) IQS(Apr 15, 1997) NAME IQS - Implicit Queuing System SYNOPSIS IQS [ -v ] [ -n processes ] DESCRIPTION IQS manages cpu-hogging jobs. A coarse-grained round- robin schedling is implemented using SIGSTOP and SIGCONT, for batch processes. No "qsub" analog (ala NQS and DQS) is available, or needed; IQS automatically detects which jobs it should manage. The -v option makes IQS say what it's doing. -n processes indicates how many processes should be run concurrently. This doesn't necessarily have to be equal to the number of processors on the machine. EXAMPLES IQS & Starts IQS for a single-processor machine. IQS -v -n 4 Starts IQS verbosely, in the foreground, for a 4-cpu machine. FILES /var/IQS/exempt-programs is a file containing names of programs not to man- age. Format is one program name per line. netscape is a common program that should be exempted. If you use this file, users may figure out that they can rename their batch programs to "netscape". The best way to contentd with this is policy. /var/IQS/exempt-users is a file containing names of users whose processes should not be managed. Format is one username per line. Some administrators may want to always exempt root, although few people run such CPU- hogging programs as root. /var/IQS/managed lists pids of managed processes, one pid per line. Unlike exempt-programs and exempt-users, this file is automatically generated. However, you can add pids and kill -HUP IQS (if you hurry, before IQS writes the pids again). SIGNALS SIGINTR Exits gracefully, allowing managed processes to run 1 IQS(Apr 15, 1997) IQS(Apr 15, 1997) freely. SIGTERM Same as SIGINTR. SIGHUP Causes /var/IQS/managed to be re-read. BUGS If a lot of CPU-hungry processes are started all at once, IQS is unlikely to manage them - because each will consume a small enough percentage of the CPU, that they do not look CPU-hungry. kill -9 leaves processes suspended. 2