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uobjnew - Summarize object allocations in high-level languages.

uobjnew(8) System Manager's Manual uobjnew(8)

NAME

uobjnew - Summarize object allocations in high-level languages.

SYNOPSIS

uobjnew [-h] [-C TOP_COUNT] [-S TOP_SIZE] [-v] {java,ruby,c} pid [interval]

DESCRIPTION

uobjnew traces object allocations in high-level languages (including "malloc") and prints summaries of the most frequently allocated types by number of objects or number of bytes.
 
This tool relies on USDT probes embedded in many high-level languages, such as Node, Java, Python, and Ruby. It requires a runtime instrumented with these probes, which in some cases requires building from source with a USDT-specific flag, such as "--enable-dtrace" or "--with-dtrace". For Java, the Java process must be started with the "-XX:+ExtendedDTraceProbes" flag.
 
Since this uses BPF, only the root user can use this tool.

REQUIREMENTS

CONFIG_BPF and bcc.

OPTIONS

-C TOP_COUNT
Print the top object types sorted by number of instances.
-S TOP_SIZE
Print the top object types sorted by size.
-v
Print the resulting BPF program, for debugging purposes.
{java,ruby,c}
The language to trace.
pid
The process id to trace.
interval
Wait this many seconds and then print the summary and exit. By default, wait for Ctrl+C to exit.

EXAMPLES

Trace object allocations in a Ruby process:
# uobjnew ruby 148
Trace object allocations from "malloc" and print the top 10 by total size:
# uobjnew -S 10 c 1788

FIELDS

TYPE
The object type being allocated. For C (malloc), this is the block size.
ALLOCS
The number of objects allocated.
BYTES
The number of bytes allocated.

OVERHEAD

Object allocation events are quite frequent, and therefore the overhead from running this tool can be considerable. Use with caution and make sure to test before using in a production environment. Nonetheless, even thousands of allocations per second will likely produce a reasonable overhead when investigating a problem.

SOURCE

This is from bcc.
https://github.com/iovisor/bcc
Also look in the bcc distribution for a companion _example.txt file containing example usage, output, and commentary for this tool.

OS

Linux

STABILITY

Unstable - in development.

AUTHOR

Sasha Goldshtein

SEE ALSO

ustat(8), ugc(8), memleak(8)
2016-11-07 USER COMMANDS