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From: geoff@ISM780.UUCP
Newsgroups: net.jokes
Subject: New System Call
Message-ID: <114@ISM780.UUCP>
Date: Tue, 26-Feb-85 01:38:28 EST
Article-I.D.: ISM780.114
Posted: Tue Feb 26 01:38:28 1985
Date-Received: Fri, 1-Mar-85 07:24:42 EST
Lines: 58
Nf-ID: #N:ISM780:29500003:000:2034
Nf-From: ISM780!geoff    Feb 25 13:00:00 1985

thrash(2)                                                        thrash(2)

    NAME
	    thrash -- reduce throughput by swapping processes
    SYNOPIS
	    #include <gigo.h>
	    #include <everything.h>

	    char  *thrash (pids, freq, mode)
	    int   *pids[];
	    int   freq;
	    char  *mode;

    DESCRIPTION
	    Thrash  allows  the  calling  process  to  reduce  system
	    performance  to  an arbitrary level by forcing the kernel
	    to swap process images.  The processes to be swapped  are
	    identified  by  *pid* in the array pids[].  Processes are
	    swapped every *freq* clock ticks (see time(2)), according
	    to the flags in *mode*.

	    Mode can be OR'd with any of the following:

		THRSHGRP 01     swap processes by group id
		THRSHLIB 02     swap only pure text segments
		THRSHPGS 04     cause page faults (for paging systems)
		THRSHSCK 08     swap only blocks with the sticky bit set
		THRSHBLK 16     indicates that the last member of pids[]
				is a blocksize (prime  numbers  give
				best results)
		THRSHCHR 32     do swapping one character at a time
		THRSHKNL 64     swap resident kernel routines
		THRSHSTK 128    swap only the stack segments

    RETURN VALUE
	    A successful call to  thrash  will  never  really  return
	    until  the  SUPERUSER  kills the calling process from the
	    system console (see  The Kernel  Debugger Tutorial).   If
	    for  some reason (e.g. very fast processor) thrash should
	    return, it will return a pointer to the name of  the  CPU
	    to  which the processor speed has been reduced to emulate
	    (i.e. 1401, 6502, pdp7 ).

    SEE ALSO
	    stopit(2), scribble(2), harass(1), dumpola(3),  unexec(3).

    BUGS
	    Only processes with  uids greater than 3  may call thrash.



 ________________________________________________________________________

	    submitted by Geoffrey Kimbrough -- Consultant to:
			  Inactive Systems Inc.
			Systems Demolition Corp.
			MicroBug Coding Services.
	      "Treating UNIX systems the way they deserve."