Provided by: bpfcc-tools_0.8.0-4_all bug


       uobjnew,  cobjnew,  javaobjnew,  rubyobjnew,  tclobjnew  - Summarize object allocations in
       high-level languages.


       cobjnew [-h] [-C TOP_COUNT] [-S TOP_SIZE] [-v] pid [interval]
       javaobjnew [-h] [-C TOP_COUNT] [-S TOP_SIZE] [-v] pid [interval]
       rubyobjnew [-h] [-C TOP_COUNT] [-S TOP_SIZE] [-v] pid [interval]
       tclobjnew [-h] [-C TOP_COUNT] [-S TOP_SIZE] [-v] pid [interval]
       uobjnew [-h] [-C TOP_COUNT] [-S TOP_SIZE] [-v] [-l {c,java,ruby,tcl}] pid [interval]


       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 C, Java,
       Ruby, and Tcl. 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.


       CONFIG_BPF and bcc.


       -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.

              The language to trace.

       pid    The process id to trace.

              Wait  this  many  seconds and then print the summary and exit. By default, wait for
              Ctrl+C to exit.


       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


       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.


       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.


       This is from bcc.


       Also  look  in  the  bcc distribution for a companion _example.txt file containing example
       usage, output, and commentary for this tool.




       Unstable - in development.


       Sasha Goldshtein


       ustat(8), ugc(8), memleak(8)