03/26/85 monitor_cache

Syntax as a command:  monitor_cache {cpu_tag} {-control_args}


Function:  initiates and controls automatic monitoring of cache memory
error data saved during normal fault processing.  This command
constantly monitors the cache memory error data to provide a warning
when error rates become excessive.  To compare error rate threshold
values, use a per process threshold or the -priv control argument
described below.  For information pertaining to changing the per-system
defaults and setting up per-process values that are different from the
per-system defaults, see "Changing the Threshold Values" below.  To
display the current threshold values, use the display_cache_threshold
command.


Arguments:
cpu_tag
   identifies the tag(s) of the CPU(s) whose cache error rates should
   be monitored.  If no CPUs are identified, all possible CPUs will be
   monitored.


Control arguments:
-brief, -bf
   suppresses the "CPU below cache error threshold" message when the
   error rate is within the specified threshold limits.  This does not
   suppress the warning when the error rate is above the threshold
   values.  This is the default.
-cpu cpu_list
   an alternate method of specifying the list of the tags of the CPUs
   whose cache error rates should be monitored.
-long, -lg
   emits a "CPU below cache error threshold" message on the user_output
   I/O switch.


-priv
   causes warning messages of "Cache above error threshold for CPU" to
   be written into the syserr_log and the bootload console with an
   audible alarm.  This control argument sends the polling message
   described under -long above to the syserr_log instead of the
   user_output I/O switch.  You must have re access to the hphcs_ gate
   to use this control argument.
-start, -sr
   resumes monitoring for the CPUs specified in the cpu_tag argument or
   the -cpu control argument.  Monitoring will continue with the next
   scheduled cycle.


-stop, -sp
   stops monitoring for the CPUs specified in the cpu_tag argument or
   the -cpu control argument.  If no CPU tags have been specified, then
   monitoring for all CPUs is terminated.
-time N, -tm N
   specifies the monitoring interval in minutes, where N is a decimal
   integer.  The default time is 15 minutes.


Access required:  You must have re access to the phcs_ gate to use this
command.


Notes on changing the threshold values:  The per-system and
per-process default threshold values are defined in
>system_library_tools>cache_threshold_defaults.  This segment is
created by a cds source segment of the same name.  To change the system
default values, you must change this source segment, recompile it, and
install the generated object in >tools.  A per-process threshold that
is different from the per-system values may be created by performing
the same operations, except that the per-process threshold should be
found in the process' object search rules before >tools or the
threshold may be specifically initiated.


Notes:  The monitor interval is closely associated with the threshold
values in that the threshold is specified in terms of an acceptable
error rate N in X time.  The default threshold values are expressed as
a per_hour_error rate.


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Historical Background

This edition of the Multics software materials and documentation is provided and donated
to Massachusetts Institute of Technology by Group BULL including BULL HN Information Systems Inc. 
as a contribution to computer science knowledge.  
This donation is made also to give evidence of the common contributions of Massachusetts Institute of Technology,
Bell Laboratories, General Electric, Honeywell Information Systems Inc., Honeywell BULL Inc., Groupe BULL
and BULL HN Information Systems Inc. to the development of this operating system. 
Multics development was initiated by Massachusetts Institute of Technology Project MAC (1963-1970),
renamed the MIT Laboratory for Computer Science and Artificial Intelligence in the mid 1970s, under the leadership
of Professor Fernando Jose Corbato. Users consider that Multics provided the best software architecture 
for managing computer hardware properly and for executing programs. Many subsequent operating systems 
incorporated Multics principles.
Multics was distributed in 1975 to 2000 by Group Bull in Europe , and in the U.S. by Bull HN Information Systems Inc., 
as successor in interest by change in name only to Honeywell Bull Inc. and Honeywell Information Systems Inc. .

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Permission to use, copy, modify, and distribute these programs and their documentation for any purpose and without
fee is hereby granted,provided that the below copyright notice and historical background appear in all copies
and that both the copyright notice and historical background and this permission notice appear in supporting
documentation, and that the names of MIT, HIS, BULL or BULL HN not be used in advertising or publicity pertaining
to distribution of the programs without specific prior written permission.
    Copyright 1972 by Massachusetts Institute of Technology and Honeywell Information Systems Inc.
    Copyright 2006 by BULL HN Information Systems Inc.
    Copyright 2006 by Bull SAS
    All Rights Reserved