NAME

prfld, prfstat, prfdc, prfsnap, prfpr − operating system profiler

SYNOPSIS

/etc/prfld [ namelist ]
/etc/prfstat [ on | off ]
/etc/prfdc [ period [ off_hour ] ]
/etc/prfsnap file
/etc/prfpr file [ cutoff [ namelist ] ]

DESCRIPTION

Prfld, prfstat, prfdc, prfsnap, and prfpr form a system of programs to facilitate an activity study of the UNIX operating system. 

Prfld is used to initialize the recording mechanism in the system.  It generates a table containing the starting address of each system subroutine as extracted from namelist.

Prfstat is used to enable or disable the sampling mechanism.  Profiler overhead is less than 1% as calculated for 500 text addresses.  Prfstat will also reveal the number of text addresses being measured. 

Prfdc and prfsnap perform the data collection function of the profiler by copying the current value of all the text address counters to a file where the data can be analyzed.  Prfdc will store the counters into file every period minutes and will turn off at off_hour. Prfsnap collects data at the time of invocation only, appending the counter values to file.

Prfpr formats the data collected by prfdc or prfsnap. Each text address is converted to the nearest text symbol (as found in namelist) and is printed if the percent activity for that range is greater than cutoff.

FILES

/dev/prfinterface to profile data and text addresses
/unixdefault for namelist file

SEE ALSO

prf(4). 

May 16, 1980