Solaris Application Programming, 1/e - Chapter 4 - Parent Directory

4.4 PROCESS- AND PROCESSOR-SPECIFIC TOOLS 73
time is the time between when the process started and when it completed. A multithreaded
process will typically report a combined user and system time that is
greater than the wall time. The tools do differ in output format. The tool timex
can be passed additional options that will cause it to report more information.
% time
Example 4.30 Syntax of the time Command
4.4.3 Reporting System-Wide Hardware Counter Activity (cpustat)
cpustat first shipped with Solaris 8. It is a tool for inspecting the hardware performance
counters on all the processors in a system. The performance counters
report events that occur to the processor. For example, one counter may be incremented
every time data is fetched from memory, and another counter may be
incremented every time an instruction is executed. The events that can be counted,
and the number of events that can be counted simultaneously, are hardwaredependent.
Opteron processors can typically count four different event types at the
same time, whereas UltraSPARC processors typically only count two. We will discuss
hardware performance counters in greater depth in Chapter 10.
cpustat reports the number of performance counter events on a system-wide
basis, hence it requires superuser permissions to run. So, if multiple programs are
running, the reported values will represent the events encountered by all programs.
If the system is running a mix of workloads, this information may not be of
great value, but if the system is performing a single job, it is quite possible that
this level of aggregation of data will provide useful information.
Assume that the system is dedicated to a single task—the program of interest—and
the program is in some kind of steady state (e.g., it is a Web server that
is dealing with many incoming requests). The command line for cpustat, shown
in Example 4.31, is appropriate for an UltraSPARC IIICu-based system. The output
is a way of determining which performance counters are worth further investigation.
Example 4.31 Sample Command Line for cpustat to Collect System-Wide Stats
$ cpustat -c pic0=Dispatch0_IC_miss,pic1=Dispatch0_mispred,sys \
-c pic0=Rstall_storeQ,pic1=Re_DC_miss,sys \
-c pic0=EC_rd_miss,pic1=Re_EC_miss,sys \
-c pic0=Rstall_IU_use,pic1=Rstall_FP_use,sys \
-c pic0=Cycle_cnt,pic1=Re_PC_miss,sys \
-c pic0=Instr_cnt,pic1=DTLB_miss,sys \
-c pic0=Cycle_cnt,pic1=Re_RAW_miss,sys