Manual Pages for UNIX Darwin command on man dapptrace
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Manual Pages for UNIX Darwin command on man dapptrace

dapptrace(1m) USER COMMANDS dapptrace(1m)

NAME

dapptrace - trace user and library function usage. Uses DTrace.

SYNOPSIS

ddaappppttrraaccee [-acdeFlhoU] [-u lib] { -p PID | command }

DESCRIPTION

dapptrace prints details on user and library function calls. By default

it traces user functions only, options can be used to trace library activity. Of particular interest is the elapsed times and on cpu times, which can identify both function calls that are slow to complete, and those which are consuming CPU cycles. Since this uses DTrace, only the root user or users with the dtracekernel privilege can run this command. OOPPTTIIOONNSS

-a print all details

-b bufsize

dynamic variable buffer size. Increase this if you notice dynamic variable drop errors. The default is "4m" for 4 megabytes per CPU.

-c print function call counts

-d print relative timestamps, us

-e print elapsed times, us

-F print flow indentation

-l force printing of pid/lwpid per line

-o print on-cpu times, us

-p PID examine this PID

-u lib trace this library instead

-U trace all library and user functions

EEXXAAMMPPLLEESS

run and examine the "df -h" command,

# ddaappppttrraaccee df -h

examine PID 1871,

# ddaappppttrraaccee -p 1871

print using flow indents,

# ddaappppttrraaccee -Fp 1871

print elapsed and CPU times,

# ddaappppttrraaccee -eop 1871

FFIIEELLDDSS PID/LWPID Process ID / Lightweight Process ID RELATIVE

relative timestamps to the start of the thread, us (microsec-

onds) ELAPSD elapsed time for this system call, us

CPU on-cpu time for this system call, us

CALL(args) function call name, with some arguments in hexadecimal DDOOCCUUMMEENNTTAATTIIOONN

See the DTraceToolkit for further documentation under the Docs direc-

tory. The DTraceToolkit docs may include full worked examples with ver-

bose descriptions explaining the output. EEXXIITT

dapptrace will run forever until Ctrl-C is hit, or if a command was

executed dapptrace will finish when the command ends.

AUTHOR Brendan Gregg [Sydney, Australia]

SEE ALSO

dappprof(1M), dtrace(1M), apptrace(1)

version 1.10 May 14, 2005 dapptrace(1m)




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