HP DCPI tool

dcpi(1)

NAME

dcpi - Digital Continuous Profiling Infrastructure

DESCRIPTION

The HP Digital Continuous Profiling Infrastructure (DCPI) system consists of a set of tools that provides low-overhead continuous profiling of all executables, including the kernel. It is based on periodic sampling using the Alpha performance counter hardware. Profiles containing samples for each executable image (including shared libraries) are stored in a user-specified directory.

Tools are provided to analyze profiles and produce a breakdown of all cpu time by image, and by procedure within images. In addition, detailed information can be produced showing the time spent executing each instruction in a procedure and the reasons for static and dynamic stalls.

For more information, see the HPContinuous Profiling Infrastructure home page.

TOOLS

dcpid

Continuous profiling daemon. Extracts raw samples from kernel device driver, associates them with executable images, and stores them in profiles on disk.

dcpiprof

Analyzes profile data collected by dcpid. Produces a breakdown of cpu time by image, or by procedures within images.

dcpilist

List the contents of a procedure and annotate the listing with samples collected during profiling via dcpid. The listing can contain either machine instructions, or source lines, or both. The listing is annotated with the samples collected during profiling, as well as the average number of cycles required to execute each instruction or source line.

dcpicalc

Annotates each instruction in a procedure's basic-block graph with the average number of cycles for that instruction, and computes the overall average cycle-per-instruction for that procedure.

dcpiwhatcg

Produces, for one or more images, a summary breakdown of where time has been spent (percent of cycles spent in, e.g., memory delays, static stalls, branch mispredicts, and useful execution).

dcpitopstalls

Produces a sorted list of the instructions accounting for the most stall cycles.

dcpidiff

Compares two sets of profiles for a procedure, highlighting basic blocks or source lines with the largest differences.

dcpisource

Augments a basic-block graph generated by dcpicalc with source code.

dcpicc

Compiles C programs to produce object code that helps dcpisource in identifying which source token each instruction corresponds to.

dcpi2ps

Formats a basic-block graph into Postscript.

dcpi2pix

Converts DCPI profile data to pixie format.

dcpictl

Controls the operation of dcpid. This subsumes dcpiepoch, dcpiflush, and dcpiquit (which are still provided for backward compatibility). Adds functionality to tell the daemon about specific images loaded into processes when necessary (e.g., when an image is loaded via mmap).

dcpiepoch

Starts a new profiling epoch. All samples are associated with a time interval called an epoch. The analysis tools typically operate on a set of profiles from a single epoch.

dcpiflush

Flushes all unsaved samples from dcpid to profiles on disk.

dcpiquit

Terminates the dcpid daemon, flushing all unsaved samples to disk.

dcpiscan

Scans filesystem directories to find executables and associate executables with filesystem pathnames.

dcpiversion

Print the version string and creation date of the installed DIGITAL continuous profiling release.

dcpiuninstall

Uninstalls DCPI binaries and man pages.

dcpicat

Prints the contents of one or more profile files in an ASCII format.

dcpiflow

Generates a basic-block graph for a procedure annotated with samples collected during profiling via dcpid. The functionality of this program has been subsumed by dcpicalc.

dcpidis

Disassembles a procedure and annotates the disassembly with samples collected during profiling via dcpid. This program is obsolete. Use dcpilist instead.

EXAMPLE USAGE

dcpiscan directories > map.local

Create an image map for site-specific executables and shared libraries in the specified directories and their descendents. Although this step is technically optional, creating a map of local executables will allow dcpid to more accurately identify binaries stored in site-specific directories. Dcpiscan(1) should be executed once during system installation, and need only be re-executed to scan other directories or newly-installed executables.

mkdir db

Make a directory to store profiles.

net start dcpisrv

Start the profiling daemon by typing this command or from the control panel.

dcpiepoch or dcpiquit

Terminate the current epoch, ensuring that profiles for that epoch are flushed to disk and won't change.

set DCPIDB = db

Set an environment variable that tells the downstream tools where the profile database is located.

dcpiprof -i

Use dcpiprof to analyze the breakdown of cpu time across all executables that ran during the epoch.

dcpiprof I

Use dcpiprof to analyze the breakdown of cpu time across all procedures in the image file I.

dcpilist -asm P I

Disassemble procedure P in the image file I, and annotate the disassembly with samples extracted from the profile database and the average cycle time required for executing each instruction.

dcpilist -source P I

Generate a source code listing of procedure P in the image file I, and annotate the listing with samples extracted from the profile database, and the average cycle time required for executing each source line.

dcpicalc -db db P I | dcpisource -f I.c | dcpi2ps -o P.ps -s 0.6

Produce a basic-block graph for procedure P in image-file I; then augment the graph with source lines from I.c, calculate the cycle per instruction for each instruction, and store the resulting Postscript in P.ps.

INSTALLATION

Installation instructions are at the HPContinuous Profiling Infrastructure home page.

SEE ALSO

dcpiflow(1), dcpiprof(1), dcpilist(1), dcpidis(1), dcpiscan(1), dcpid(1), dcpiepoch(1), dcpiflush(1), dcpicalc(1), dcpilabel(1), dcpi2ps(1), dcpicat(1), dcpiquit(1), dcpidiff(1), dcpitopstalls(1), dcpiwhatcg(1), dcpictl(1), dcpiformat(4)

For more information, see the HPContinuous Profiling Infrastructure project home page (http://www.unix.digital.com/dcpi).

COPYRIGHT

Copyright 1996-2004, Hewlett-Packard Development Company, L.P.

AUTHORS

Jennifer Anderson, Lance Berc, Jeff Dean, Sanjay Ghemawat, Monika Henzinger, Shun-Tak Leung, Mitch Lichtenberg, Dick Sites, Mark Vandevoorde, Carl Waldspurger, Bill Weihl.

This page was generated automatically by mtex software.