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dcpi(1)
NAME
dcpi - HP Digital Continuous Profiling Infrastructure
DESCRIPTION
The HP Digital Continuous Profiling Infrastructure (HP 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.
Note that by default, input such as procedure names is in lower case. Where
case is significant, enclose the procedure name in quotation marks (").
Note: Symbolic information is created for a program if the program is compiled with
the /DEBUG qualifier, and if the program is linked with the /DEBUG or /DSF qualifier. If the /DSF qualifier is used
to link the program, symbolic information is available if either of the
following is true: - The DSF file resides in the same directory as the program
image
- Logical name DBG$IMAGE_DSF_PATH points to the directory in which the
DSF
file resides.
Without the symbolic information, the analysis tools
can do only top level image analysis.
For more information, see the HP Digital Continuous Profiling Infrastructure
home page.
TOOLSSampling Tools
- dcpid
- Continuous profiling daemon. Extracts raw samples from kernel device
driver, associates them with executable images, and stores them in profiles
on disk.
- dcpictl
- Controls the operation of dcpid. Additionally,
dcpictl can be used to provide specific information to the DCPI daemon.
Analysis Tools
- 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, for example, 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.
- dcpi2ps
- Formats a basic-block graph into PostScript.
- dcpicat
- Prints the contents of one or more profile files in an ASCII format.
- dcpiprof
- Analyzes profile data collected by dcpid. Produces a breakdown of
samples
by image, or by procedures within images. In the absence of symbolic information,
dcpiprof accepts address range input such as 0x20100:0x20300.
- dcpilist
- Lists 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. In the absence of symbolic information,
dcpiprof accepts address range input such as 0x20100:0x20300.
- 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.
INSTALLATION
Installation instructions are located at the DCPI installation page.
SEE ALSO
dcpi(1),
dcpi2ps(1),
dcpicat(1),
dcpictl(1),
dcpid(1), dcpidiff(1), dcpiformat(4), dcpilist(1),
dcpiprof(1),
dcpitopstalls(1),
dcpiwhatcg(1)
For more information, see the HP Digital Continuous Profiling Infrastructure
project home page
(http://h30097.www3.hp.com/dcpi).
Comments
Last modified: April 8, 2004
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