1 02/28/85 work_class_meters, wcm
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3 Syntax as a command: wcm -control_arg
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5
6 Function: prints certain information from the tc_data segment about
7 each work class currently defined.
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9
10 Control arguments:
11 -report_reset, -rr
12 generates a full report and then performs the reset operation.
13 -reset, -rs
14 resets the metering interval for the invoking process so that the
15 interval begins at the last call with -reset specified. If -reset
16 has never been given in a process, it is equivalent to having been
17 specified at system initialization time.
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20 Access required: This command requires access to phcs_ or
21 metering_gate_. Additionally, in order for the command to print the
22 names of the work classes, access to both the Master Group Table MGT
23 and the answer table is required. These tables are located in the
24 directory >system_control_1.
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27 Notes: If the work_class_meters command is given with no control
28 argument, it prints a full report.
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30 When the scheduler is operating in percent mode, percentages are
31 computed against two different base CPU quantities. It is necessary to
32 understand the differences between these quantities in order to
33 interpret the output of work_class_meters.
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36 One base quantity is the total system CPU time. This is simply the
37 total realtime all CPUs have been active doing anything including
38 running an idle process. In any interval of time when there was no
39 reconfiguration of CPUs, the total system CPU time is the product of
40 the length of the interval and the number of CPUs. Another base
41 quantity is nonidle CPU time. This is the total CPU time expended by
42 all CPUs except when running an idle process. It is given by the total
43 system CPU time minus the sum of all idle time reported by
44 total_time_meters MP Idle Non-MP Idle and Zero Idle.
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47 When the scheduler is operating in percent mode, it distributes CPU
48 resources among contending work classes according to their guaranteed
49 percentages. These percentages are percentages of total nonidle CPU
50 time. So, if there are two work classes, each with a guarantee of 50
51 percent, and the system is 50 percent idle, each work class gets 25
52 percent of total system CPU time assuming that there is enough demand
53 for this to be possible. In this example, each work class is getting
54 50 percent of the nonidle CPU time, but only 25 percent of the total
55 system CPU time. Another way of viewing this is that the guaranteed
56 percentages define a relationship among work classes according to the
57 ratio of percentages. That is, a work class with a guaranteed
58 percentage of 10 percent gets about half as much CPU time as a work
59 class with a guaranteed percentage of 20 percent, assuming sufficient
60 demand by both. Further, this ratio is independent of the system load.
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63 The system administrator can limit the CPU resources consumed by a work
64 class to a fixed percentage of the total system CPU time. The
65 scheduler enforces this limitation, even at the expense of going idle.
66 That is, a work class with a maximum percentage of 10 percent gets no
67 more than 10 percent of the total CPU time in any interval, regardless
68 of load. Excess CPU time is distributed among work classes with no
69 maximum percentage, according to their guaranteed percentages. If this
70 cannot be done, the excess CPU time becomes idle time.
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72 At any time one or more work classes may be a realtime work class with
73 specified response time and quanta. A process in such a work class is
74 low priority until its deadline arrives, at which time it is made
75 eligible regardless of any other constraints. The remainder of the
76 work classes are scheduled either by percentage of CPU time percentage
77 mode or by soft deadlines deadline mode.
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80 The following parameters are always displayed for each work class.
81 WC
82 is the number of the work class.
83 %GUAR
84 is the percentage of nonidle CPU time guaranteed to the work class
85 if the scheduler is being operated in percent mode and if there is
86 sufficient demand by the work class for this to be possible.
87 %MAX
88 is the maximum percentage of total CPU time allowed by the system
89 administrator to be consumed by this work class. This field is
90 blank if the work class has no limitation on CPU consumption.
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92
93 %TCPU
94 is the percentage of total CPU time actually received by this work
95 class in the metering interval.
96 V/ELIG
97 is the average amount of CPU time used per eligibility quantum.
98 PW
99 is the pin weight, or number of free laps for pages brought into
100 memory.
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102 The following parameters are always displayed for realtime work
103 classes, and are displayed for other work classes only if the scheduler
104 is operating in deadline mode.
105 IRESP
106 is the response time in seconds specified for the work class after
107 an interaction.
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110 IQUANT
111 is the initial quantum in seconds for the work class after an
112 interaction.
113 RESP
114 is the specified delay in seconds between subsequent quanta.
115 QUANT
116 is the value in seconds of subsequent quanta.
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118 The following parameters are displayed when the scheduler is operating
119 in either deadline or percentage mode.
120 P
121 if printed, members of the work class are post purged.
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124 M
125 is the max_eligible limit per work class. A zero means the work
126 class has no particular limit.
127 R2
128 if printed, the members of the work class are scheduled in realtime
129 mode. They are made eligible at or before their deadlines.
130 I
131 if printed, members of the work class are given scheduler priority
132 after interactions.
133 LCG
134 are the load control groups that are placed in the work class. If
135 the LCG name is parenthesized, only the absentee processes in the
136 LCG are placed in the work class.