freebsd-dev/cddl/contrib/dtracetoolkit/Man/man1m/js_objgc.d.1m
2012-05-12 21:25:48 +00:00

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.TH js_objgc.d 1m "$Date:: 2007-10-03 #$" "USER COMMANDS"
.SH NAME
js_objgc.d - trace JavaScript Object GC using DTrace.
.SH SYNOPSIS
.B js_objgc.d
.SH DESCRIPTION
This traces JavaScript activity from all running browers on the system
which support the JavaScript DTrace provider.
This script provides information on which objects are not being garbage
collected, an issue which causes the browser to steadily leak memory.
We trace object creation (+1) and destruction (-1), and provide a
summary each second of the running tally of the object class and
originating filename. If over the period of several minutes an object
type is still steadily increasing, then that would be of interest.
Be patient, depending on the rate of object creation it can take over
ten minutes for garbage collect to kick in.
.SH OS
Any
.SH STABILITY
Evolving - uses the DTrace JavaScript provider, which may change
as additional features are introduced. Check JavaScript/Readme
to see what version these scripts are based on.
.SH EXAMPLES
.TP
Default output,
#
.B js_objgc.d
.PP
.SH FIELDS
.TP
FILE
Filename that contained the function
.TP
CLASS
Class to which this new object belongs
.TP
TOTAL
Object entropy (positive == uncollected)
.SH NOTES
\- it is possible that you will see negative entropy. That happens
when you begin tracing after some objects have already been created,
and then trace their destruction.
\- there are other Things that GC handles, other than Objects; extra
probes can be added to trace them, should the need arise.
.PP
.SH DOCUMENTATION
See the DTraceToolkit for further documentation under the
Examples, Notes and Docs directories. The example files may be
especially useful as they aim to demonstrate how to interpret
the output.
.SH EXIT
js_objgc.d will run until Ctrl-C is hit.
.SH AUTHOR
Brendan Gregg
[CA, USA]
.SH SEE ALSO
dtrace(1M)