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File: METER	Node: Top	Up: (DIR)

METER is a program to display a variety of system statistics.
It differs from PEEK in that it shows only system-wide
information, not per-job.  It also gives a lot of statistics
that PEEK won't.

On a display terminal (%TOERS and %TOMVU) METER will periodically
update its display, changing only those numbers that have
accidentally changed.  On other terminals, it just types the
whole thing out over and over again.

METER does not take any options.  It stops when you hit space.
If it is invoked by :METERD it will display on the 340.

If it is invoked by :SMETER, it will repeat slower.

The first display shows figures which for the most part are averages
over the whole time that the system has been up.  After that, all
figures are averaged over the last 15 seconds or so.

The statistics displayed are explained below.  All times are in seconds.
All numbers are [of course] decimal.  "ATB" means average time between.

% User Time - fraction of CPU time given to users.

% Idle      - fraction of CPU time not used.

% Overhead  - fraction of CPU time spent on system overhead - page
              fault handling, TTY and Disk I/O, scheduling, etc.

# Processes - the total number of processes (jobs, procedures)
              on the system.

% active last 15 seconds - fraction of processes which ran at least
              for a moment sometime within the last 15 seconds.

% Processes running - fraction of processes currently running
              user programs.

% Exec run  - fraction of processes currently running in the system.

% Blocked   - fraction of processes currently waiting for something,
              such as type in, a page to be swapped in, etc.

% Stopped   - fraction of processes currently unrunnable - usually
              this is due to ^Z, er, ah, CALL.  Swap-blocked processes
              are also counted here.

Disk ATB read - average time between disk reads for file accesses.

         write - average time between disk writes for file accesses.

         PgIn - average time between disk reads for swapping in pages.

         PgOut - average time between disk writes for swapping out pages.

TTY ch/s in - characters per second input from TTY's.

TTY ch/s out - characters per second output to TTY's.  This does not
              include TV's, and does not count cursor motion accurately.
              Since ITS does not keep this meter, the METER program
              estimates it by looking at the teletype buffers frequently.

ATB Sched   - average time between reschedulings.

ATB PCLSR   - average time between attempts to force a process into
              user mode so it can be stopped or take an interrupt.
              There may be several attempts for each successful
              PCLSR.

ATB swap out - average time between attempts to swap out a process.

ATB page faults - average time between page faults.

       % in - fraction of page faults on pages already in core.

   % coming - fraction of page faults on pages already coming into
              core due to a previous page fault.

      % out - fraction of page faults on pages not in core.  These
              are the "real" page faults.

    % going - fraction of page faults on pages on their way out of
              core.  The page will have to come right back in.

              The above four numbers usually don't add up to 100%.
              The rest of the page faults are those which occurred
              while a page-control lock was locked, and therefore
              had to be taken over again after a delay.
