PDP-10.stacken/files/stacken-tape-backup/dskb:10_7/scdset/scdset.mem

SCDSET.MEM -- For Version 3 of SCDSET
Jan 1978






























COPYRIGHT (C) 1977,1978 BY
DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASS.


THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY BE USED AND  COPIED
ONLY  IN  ACCORDANCE  WITH  THE  TERMS  OF  SUCH  LICENSE AND WITH THE
INCLUSION OF THE ABOVE COPYRIGHT NOTICE.  THIS SOFTWARE OR  ANY  OTHER
COPIES  THEREOF MAY NOT BE PROVIDED OR OTHERWISE MADE AVAILABLE TO ANY
OTHER PERSON.  NO TITLE TO AND OWNERSHIP OF  THE  SOFTWARE  IS  HEREBY
TRANSFERRED.

THE INFORMATION IN THIS SOFTWARE IS SUBJECT TO CHANGE  WITHOUT  NOTICE
AND  SHOULD  NOT  BE  CONSTRUED  AS  A COMMITMENT BY DIGITAL EQUIPMENT
CORPORATION.

DIGITAL ASSUMES NO RESPONSIBILITY FOR THE USE OR  RELIABILITY  OF  ITS
SOFTWARE ON EQUIPMENT WHICH IS NOT SUPPLIED BY DIGITAL.
SCDSET.MEM                                                      Page 2


SCDSET:  A Scheduler Parameter Setting Program
     for use by the System Administrator



1.0  OVERVIEW


1.1  Purpose

The purpose of this program is to allow the  System  Administrator  to
easily use the SCHED.  Monitor call as implemented in the DECsystem-10
6.02 monitor.  (This monitor call allows  a  privileged  user  to  set
system  usage  quotas  as  well  as  adjust scheduler parameters.) The
program is written so that the System Administrator can  exercise  the
monitor call easily without having to know how it was implemented.  In
addition SCDSET:

     1.  Allows the System Administrator to create/modify a SCDMAP.SYS
         file (which maps Scheduler Types to Scheduler Classes).

     2.  Allows the System Administrator to move any  SCDMAP.SYS  file
         to  the  SYS  area  (so that the new map is being used by new
         LOGIN's).

     3.  Allows the System Administrator to automatically  update  the
         class of all logged in jobs.


1.2  Relation to Other Programs

This Version of SCDSET  is  valuable  only  for  a  site  running  the
scheduler  LIR  and  Version  6.03  or  6.04 and later versions of the
DECsystem-10 monitor.  Several of SCDSET's auxiliary functions require
Version  4  of  ACCT.SYS.   This  requires new versions of three other
systems/programs that access ACCT.SYS:  LOGIN (Version 56A or  later),
REACT (Version 31 or later) and SPRINT-10 (Version 2A(1056) or later).


1.3  DESIGN Goals

     1.  Write a simple, easy to use program that has enough hooks  to
         do anything that the SCHED.  monitor call can do.

     2.  Implement  it  in  some  higher  level   language   so   that
         modification of SCDSET by the System Administrator is easier.
         (FORTRAN-10 was chosen arbitrarily.)
SCDSET.MEM                                                      Page 3


1.4  Bibliography

See the System Administrator's Guide to the 6.02  Scheduler,  and  the
appropriate documentation of REACT, LOGIN, and SPRINT-10.



2.0  PRIVILEGES REQUIRED

For manipulating a SCDMAP.SYS file, no privileges are required (except
as needed to move that file to the SYS area).

For exercising the SCHED.  monitor call, all privileges are  required.
The  user  must  be  logged  in as [1,2], or the program must be JACCT
priviledges.  These are the restrictions of the monitor call.

The READ/SET functions of SCDSET assume the user  is  [1,2]  and  will
otherwise fail.



3.0  CAUTIONS

The System Administrator is strongly advised to run SCDSET in  a  high
priority   queue  (HPQ).   This  will  assure  that  his/her  work  is
unaffected by system quota's and system load.

HPQ is not required when creating/modifying a SCDMAP.SYS file, and  is
in  fact  discouraged  because it has a detrimental effect upon system
performance.



4.0  FUNCTIONS

The program SCDSET prompts the  user  with  a  message  asking  for  a
command  (and  optionally  a parameter selecting a particular function
associated with the command).  The user  types  in  the  name  of  the
command and if necessary the optional parameter.

Commands:

     1.  HELP - Types out help text.

     2.  EXIT - Returns to the monitor
SCDSET.MEM                                                      Page 4


4.1  Update Jobs

The UPDATE JOBS command calls the FIXJOB routine.  This routine  first
reminds  the System Administrator that a new SCDMAP.SYS file should be
on the SYS area by asking him if he wishes to move one there.  If  the
System  Administrator  does want to move a map to the SYS area, FIXJOB
calls the MOVMAP routine to do that work.  FIXJOB  then  runs  through
each  logged in job, gets that job's PPN, determines whether or not to
use the batch half of  the  SCDMAP.SYS  currently  on  SYS,  looks  in
ACCT.SYS  for the Scheduler Type of that user, and executes the SCHED.
monitor call to put that job in the right Scheduler Class.  It  prints
out  an  error  message  for  each  logged in job it could not find in
ACCT.SYS or for which the SCHED.  monitor  call  failed.   The  FIXJOB
routine  does  not execute the SCHED.  monitor call for [2,5] jobs, or
for its own job.


4.2  EDIT

The EDIT Command calls  the  MAKMAP  subroutine.   This  routine  will
create/modify  a  SCDMAP.SYS  file.   There  are eight (8) subcommands
available:

     1.  HELP - Type out a help text.

     2.  EXIT - Exit to top level.

     3.  READ - Read in a SCDMAP.SYS file for modification.

     4.  WRITE - Write out a SCDMAP.SYS file to any device or area.

     5.  RANGE - Change any range  of  Scheduler  Types  to  scheduler
         Classes in the map.

     6.  ONE CLASS - Change one Scheduler Type to a Scheduler Class in
         the map.

     7.  TYPE - Type out any range of Scheduler Types.

     8.  COPY/SET - The COPY command calls the MOVMAP  routine.   This
         function  merely copies a file from any area or device to the
         SYS area.  PIP should be able  to  do  this  work,  but  this
         routine  is  provided  for  the  convenience  of  the  System
         Administrator.
SCDSET.MEM                                                      Page 5


4.3  READ/SET Functions

The user types READ or SET on the keyboard followed by a comma  and  a
parameter  form  the following list.  These functions directly execute
the SCHED.  monitor call.

     1.  MS  INTERVAL - This  function  reads  or   sets   the   Micro
         Scheduling  Interval.   (The  interval at which the scheduler
         changes which class it will select from first during the next
         scheduling interval).  The interval is in jiffies.

     2.  PRIMARY PERCENTAGES - System usage percentage for a particlar
         job  class.  The sum of all primary percentages may be fixed,
         in which case a job will only be chosen to run when its class
         has highest priority.

     3.  TIME BASE - Base run  quanta  for  either  run  queue.   This
         measurement  is  in  milliseconds.  (Internally the Scheduler
         stores this value in local jiffies, so it may not be possible
         to adjust the time slice by a few milliseconds.)

     4.  JOB CLASS - This function reads or sets the  Scheduler  Class
         of all logged in jobs.

     5.  PROTOT - This function reads or sets the  Scheduler  constant
         called  PROTOT.   It  is one of the three constants used when
         calculating the Minimum Core Usage quota.  The measurement is
         in microseconds.

     6.  RUNTIME BY CLASS - This function reads the amount of  runtime
         used by each class since the last time that a class quota was
         changed.  The measurement is in jiffies.   The  routine  also
         prints out the percentage of runtime each class has used.

     7.  PROT - This function reads or sets the value of the Scheduler
         constant  called  PROT.   It  is one of the constants used in
         calculating the Minimum Core Usage quota.  The measurement is
         in microseconds.

     8.  DEFAULT CLASS - This is the default class that new  jobs  are
         placed  into when they first login.  This class is used until
         it is changed by LOGIN after LOGIN has read the specified job
         class from SCDMAP.SYS.
SCDSET.MEM                                                      Page 6


     9.  PROT1 - The in-core timeslice  used  after  a  job  has  been
         either  expired  its  initial  in-core  protect  time.   This
         control the rate at which I/O bound jobs circulate around the
         run queues.

     10. PROTM - PROTM is the maximum in-core protect time  that  will
         be  assigned  to a job.  It specifies an upper bound for very
         large jobs.

     11. TIME MULTIPLIER - Used to assign a larger quantum runtime for
         large  jobs.   The  quantum runtime is computed by adding the
         TIME BASE to the TIME MULTIPLIER multiplied by the job  size.
         The  result  is  compared with a run quantum maximum, and the
         smaller of the computed value or maximum is used.

     12. TIME MAXIMUM - The maximum quantum runtime that is  used,  as
         described above.

     13. SECONDARY  ALLOCATION - The  secondary   allocation   for   a
         scheduler  class.   When  no runnable job can be found in the
         primary class that has been selected to be in  proportion  to
         their secondary allocation.

     14. RESPONSE FAIRNESS - The response fairness factor control  how
         often  jobs will be run according to their order in the "just
         swapped in list", in preference to the allocations  specified
         by the job classes.

     15. AVG SWAP TIME - This parameter is an estimate of the  average
         swap  time  for a typical job in the system.  it controls the
         rate at which the swapper changes from one class to the  next
         in chosing jobs to swap in.

     16. BB CLASS - Selects which class is background batch,  a  class
         that is run whenever the system is otherwise idle.

     17. BB SWAP TIME - Estimate  of  the  time  required  to  swap  a
         background  batch  job.   This  is  used  by the scheduler to
         decide when the system has been idle long  enough  to  permit
         swapping in a background batch job.

     18. SCHEDULER FAIRNESS - This parameter determines how  oten  PQ2
         jobs  will  be  scheduled  ahead of PQ1 jobs.  This parameter
         allows compute bound jobs to run (albeit  slowly)  even  when
         there is an abundance of interactive jobs.
SCDSET.MEM                                                      Page 7


     19. SWAPPER FAIRNESS - This parameter determines  how  often  PQ2
         jobs  are swapped in before PQ1 jobs.  It has the same effect
         on the swapper as the scheduler fairness factor  has  on  the
         scheduler.

     20. INCORE FAIRNESS FACTOR - The parameter control how  often  an
         out of core job is scheduled before for swapping before a job
         that is already in core.  This allows jobs to be  swapped  in
         when many jobs that are already incore are doing GETSEG's.

     21. CORE SCHEDULING  INTERVAL - This  controls  how  quickly  the
         system will assume that there is sufficient core for all jobs
         and stop accounting for incore protect time and using  it  to
         requeue jobs.  This happens on systems with a large amount of
         core memory or when the system has very few users.



5.0  COMPILING INSTRUCTIONS

There are two modules necessary to compile and run SCDSET.   They  are
SCDSET.FOR  and  SCDEXE.MAC.   SCDSET  contains  the top level command
loop, the error message routine, all the functions, and routines to do
all  the  work  required by the System Administrator.  SCDEXE contains
the few MACRO routines necessary to execute the SCHED.   monitor  call
and  to  gather  environmental information not available from FORTRAN.
Version four (4) of the FORTRAN-10 compiler was used to  compile  this
code.  Any MACRO should be able to handle the SCDEXE module.  A simple
"LOAD SCDEXE, SCDSET" and then a save should be sufficient to  make  a
copy of the SCDSET program.



6.0  THE SCDMAP.SYS FILE

The SCDMAP.SYS file should always be on the SYS area when your  system
is  running  a  6.02 monitor and a LOGIN that sets 6.02 quotas.  LOGIN
will complain if there is no SCDMAP.SYS file on SYS.

The file contains 1024 (decimal) nine bit entries (256 decimal words).
The  first  512  entries  constitute  the map for timeshare users, the
second 512 entries constitute the map for  batch  users.   Each  entry
contains  a  number  between  zero  and  thirty-one  inclusive  (0-31)
specifying a Scheduler Class.  There is an entry for each of  the  512
Scheduler  Types  for  both  timeshare and batch.  Thus at login time,
LOGIN looks in ACCT.SYS for the Scheduler Type of  the  PPN  and  then
looks in SCDMAP.SYS for the current Scheduler Class for that Scheduler
Type and job type (timeshare or batch).  For sites that do not wish to
differentiate  between timeshare and batch, the second half of the map
should be identical to the first half.
SCDSET.MEM                                                      Page 8


The format of the SCDMAP.SYS file is as follows:

                          bits

               0-8       9-17      18-26    27-35
           *****************************************
word 0     *        *    n0   *    n1   *   n2     *
n3   *     *                                       *
           *****************************************
word 1     *        *    n4   *    n5   *   n6     *
n7   *     *                                       *
           *****************************************
word 2     *        *    n8   *    n9   *   n10    *
n11  *     *                                       *
           *****************************************
           /                                       /
           /                                       /
           *****************************************
word 127   *   n508 *    n509 *    n510 *   n511   *
           *****************************************
word 128   *   m0   *    m1   *    m2   *   m3     *
           *****************************************
word 129   *   m4   *    m5   *    m6   *   m7     *
           *****************************************
word 130   *   m8   *    m9   *    m10  *   m11    *
           *****************************************
           /                                       /
           /                                       /
           *****************************************
word 255   *   m508  *   m509  *   m510  *  m511   *
           *****************************************

***where nXXX is the location of the  Scheduler  Class  for  timeshare
users  of  Scheduler Type XXX (as stored in ACCT.SYS), and mXXX is the
location of the Scheduler Class for batch users of Type XXX.



7.0  WARNINGS

It is very easy when using SCDSET to halt all  productive  work  being
done  on  the  system.  Misunderstanings of how the scheduler works or
typing errors  when  using  SCDSET  could  drastically  affect  system
performance.  The System Administrator is strongly urged to experiment
with  this  program  and  the  6.02  scheduler  during  non-production
timesharing,  until  he/she  becomes familiar with both SCDSET and the
scheduler.



[End of SCDSET.MEM]