tcl.buf-map

Verb: Access/TCL, Releases: AP

Displays a map of the buffers.

Syntax

buf-map {minfid-maxfid} {(options)}

Description

displays a visual 'map' of the filesystem, indicating which frames are currently being held in the RAM buffer area, and updates the display every few seconds.

The buffer map is laid out as a grid of frame addresses for the entire system (bottom left-hand corner is fid-1, and top right-hand corner is maxfid), and displays which fids are currently active in the buffers.

'minfid' and 'maxfid' are the minimum and maximum FID numbers to be included in the result.

The buffer displays a number between 0 - 7, which indicates the buffer's 'state'. The values are shown in the upper right-hand corner as a reminder.

Press 'x' to exit the display.

Options

s Sample about 10% of the memory, rather than reading all buffers in memory. This option provides a quick snapshot of the memory usage, but is less accurate.

Example

buf-map

1-358398. Fid loaded: 8740. 8742 buffers. Type H for help.
- - - - - - - - - - - - - - - - - - - - - - - - - - - 2265
1 : 5 : R
2 : W 6 : RW
3 : B 7 : RB 6
4 : BW 8 : RBW 6
- - - - - - - - - - - - - - - - - - - - - - - - - - -6- 1700
5
5 5
5 5
5 5
5- - - - - - - - - - - - - - - - - - - - - - - - - - -5- 1135
5 5
5 5
5 5
5 5
5- - - - - - - - - - - - - - - - - - - - - - - - - - -5- 570
5 56
5 1 5 56
5 11 5 16
1 5 51111 15
+---------+---------+---------+---------+---------+---------+
Range 1 to 358398. Hit X to stop.. 0000

States:

The diagram shows the different 'states' of the buffers in memory by
a number as shown in the state table below.

With the 's' option, only a sample is taken.


Refer'cd Batch Write-req State
0 0 0 1 Available
0 0 1 2
0 1 0 3 Available
0 1 1 4
1 0 0 5
1 0 1 6
1 1 0 7
1 1 1 8

During the sampling, type:

h To display this screen.
s To stop sampling and display results.
x To exit the process.

See Also

Command Name Type Description
tcl.buffers.g Verb: Access Produces histogram of system performance.
tcl.monitor-status Verb: Access Gets monitor statistics and buffer table information.
tcl.flush Verb: Access Flushes write-required frames to disk.
tcl.frame-fault Verb: Access Tests write frame faults.
flusher Definition Description of flusher.
tcl.buffers Verb: Access Displays virtual memory buffer status.

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