POST

General Information

Overview

ITRACE Data Reduction

TPROF Data Reduction

Options

Overview

post is used to reduce data gathered by the SWTRACE trace mechanism. Swtrace is currently used to gather both TPROF and ITRACE data, depending on which major codes are activated. The Options to POST include:
1. common options that apply to either TPROF or ITRACE,
   
2. options specific to TPROF and
   
3. options specific to ITRACE.

post reduces all swtrace data collections and will evolve as additional hooks are defined.

The "-verbose" option enables the writing of all optional messages to stderr. By default, only actual error messages will be written.

The "-showx" option decodes a swtrace.nrm2 file into an ascii file (post.show) without any further processing. This is useful as a generic data reduction for any combination of the swtrace hooks, allowing for further specific reduction on the resulting post.show file.

ITrace Data Reduction

ITrace data, in an swtrace.nrm2 file can be processed two ways:

1. Summary approach: post

   post, by default, rolls up individual ITrace records into a tree format (ptree file). This is the preferred approach for large ITrace files since no large intermediate files are generated.

2. Detailed approach: post -arc [-c] [-ss] [-ssx]

   post with the -arc option generates one record per branch record. With the -c option the data is compressed to the subroutine level: all contiguous records in the same subroutine are collapsed together. The -ss option provides embedded disassembled instructions. The -ssx option adds actual instruction bytes to the instruction record.

Tprof Data Reduction

post generates the "tprof.out" report whenever there are tprof hooks in the trace. The typical invocation of post for tprof is :

1. post [-clip N] [-off] [-jdir path/prefix]

   See Tprof Reports for sample reports.
   -clip N clips report entries at N%. The default is no clipping.
   -off creates an "offset" report stanza and creates another file "tprof.micro". This report contains symbol filenames, tick symbol offsets, and line numbers.
   -jdir is used in conjunction with the jprof fnm= option. This locates the jprof jita2n files to allow jit address resolution.

Options

-off

creates a tprof.micro file that has tick annotated disassembly of subroutines. This is shown in a MOD_SYM_OFF format.
To microprofile JAVA methods use jprof option "tprof" or a combination of "jinsts" and "jita2n".

-rsel rrrrrrrr

Allows selection of any subset of the 8 standard reports.
The order of the 8 reports is P, PM, PMS, PT, PTM, PTMS, M, & MS,
where P= ProcessID, T=ThreadID, M=Module andS=Symbol.
For example, to generate only the Process and Process_Thread reports use-rsel 1001000.

-x xfile

Define additional custom reports in thexfile file. Each line defines a report where PID=1, TID=2, MOD=3, SYM=4, OFF=5.
For example, a single line xfile containing "31" creates a MOD_PID report.

-twin b e

Generate a windowed tprof.out report starting at the b-thtick and ending with the e-th tick.

-clip pc

Clip tprof reports at pc%. That is, only show entries (at any level) that are >= pc% of the total ticks. The default is 0 %.

-pnm

PID's with the same pnm are merged. The PID level name changes from pnm_pid to pnm.

-cpu

Adds CPU resolution at the PID level. Thus you get a CPU level tprof. The PID level name is changed from pnm_pid to pnm_pid_cpu.

-ring0 x

Ability to summarize ring0 activity. x=1, default, is for full detail. x=0 results in ring0 activity being summarized to a single entry for each pass into ring0.

-k kpath & -kmap kpath

These 2 options, for Linux only, locate the source of kernel symbols. The running kernel typically has only a subset of the kernel symbols. If neither option is specified the default path is /usr/src/linux/vmlinux. The -k option gives the path to a non-stripped Linux kernel. The -kmap option gives the path to a kernel map file.

-nv

Don't validate symbols. Use this option to reduce a trace taken with a kernel other than the currently running one. In this case you may also need to use the -k option to point to the correct non-stripped kernel.

-lmrg fnm

Selects a "load merge" file, which specifies the symbols to be used for reducing a swtrace.nrm2 file. This allows reduction on a machine other than tracing machine or on the same machine after modules have been changed.
To generate the file run "genmsi" on the trace machine to gather all non-java symbols. For java symbols copy all the generated llog-jita2n files to the reducing machine.

-jdir fnmpath

To acquire Java JITTED method symbols add command line options when starting java (see jprof documentation). The default is to the current directory.
A sample java invocation is shown below:

java -Xrunjprof:tprof,logpath=/work/,logprefix=log hellop 10000

The"logpath" option puts jita2n files into the specified directory ( /work ), with the specifies prefix ( log ).
If the java fnm option is used post must use the "-jdir" to access the jita2n files. For the java invocation above, the post command needs to be:

post -jdir /work/log


-sympath path

Specify an auxiliary list of directories for symbols. path is a comma delimited list.

-compat

Omit the line specifying tprof mode and rate from a tprof.out report.