September 2002
Beginner to intermediate
216 pages
7h 43m
English
Content preview from Mac OS X for Unix Geeks
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sc_usage
The sc_usage utility samples system calls and page faults, displaying them onscreen. sc_usage must be run by root or by someone who has superuser privileges. The display is updated once per second. You must specify a PID, a command name, or a program to execute with the -E switch. For example, to monitor the Finder, use sc_usage Finder. Figure 8-2 shows the output of running sc_usage on the Finder. Table 8-3 explains sc_usage’s output.
 |
Figure 8-2. sc_usage monitoring the Finder
Table 8-3. Information displayed by sc_usage
|
Item number |
Row |
Description |
1 |
TYPE |
The system call type |
2 |
NUMBER |
The system call count |
3 |
CPU_TIME |
The processor time used by the system call |
4 |
WAIT_TIME |
The absolute time that the process spent waiting |
5 |
CURRENT_TYPE |
The current system call type |
6 |
LAST_PATHNAME_WAITED_FOR |
The last file or directory that resulted in a blocked I/O operation during a system call |
7 |
CUR_WAIT_TIME |
The cumulative time spent blocked |
8 |
THRD# |
The thread ID |
9 |
PRI |
The scheduling priority |
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