 |
Index for
Section 1 |
|
 |
Alphabetical
listing for U |
|
 |
Bottom of
page |
|
uprofile(1)
NAME
uprofile, kprofile - Profile a program (uprofile) or kernel (kprofile) with
Alpha on-chip performance counters
SYNOPSIS
uprofile [-v] [-quiet] [-dirname path] [-[no]pids] [-all | -each | -one]
[-stride n] [-average] [-pixie] [-display | prof-option...] [statistic...]
program [argument...]
kprofile [-v] [-quiet] [-dirname path] [-[no]pids] [-all | -each | -one]
[-stride n] [-average] [-pixie] [-display | prof-option...]
[-k kernel_name] [-t] [-ra] [statistic...] [program [argument...]]
DESCRIPTION
See prof_intro(1) for an introduction to the application performance tuning
tools provided with Tru64 UNIX.
The uprofile command uses the Alpha on-chip performance counters to produce
a finely-grained program-counter profile of a user program. The command
runs the program you specify with the arguments you specify, collecting the
selected statistics on the program's process and its descendants. It writes
the profile data to the umon.out file, by default. If the program calls
shared libraries, those libraries are not profiled.
The kprofile command uses the Alpha on-chip performance counters to produce
a detailed program-counter profile of the kernel. If you specify a program,
kprofile runs the program with the arguments you specify, and it collects
the selected statistics on the kernel for the duration of the program's
execution. If you do not specify a program, kprofile collects the selected
statistics on the kernel until you enter Ctrl/C or the kprofile process
receives a SIGTERM signal. Note that if SIGINT (usually generated by
entering a Ctrl/C at the controlling terminal) is currently being ignored,
it will continue to be ignored and SIGTERM must be used to terminate data
collection. kprofile writes the profile data to the kmon.out file, by
default.
If you specify -display or any of the prof-options, the uprofile and
kprofile commands display the profile by runnning the prof tool (with any
specified prof-options).
You can also run the prof command separately, to help analyze the data in
the umon.out or kmon.out file. The following examples show how to invoke
the prof command to analyze data in the respective files:
% prof a.out umon.out
% prof /vmunix kmon.out
The CPU-time profile displayed by prof will not be accurate if the CPU
speed of the processors that executed the application are not the same, as
in certain multiprocessor systems containing EV67 or later processors. The
inaccuracy may be avoided by using the hiprof (sampling) or cc -p/-pg
profilers, or by running the application on a subset of the processors:
· Select a single processor using the runon command.
· Check the processor speeds using the psrinfo -v command and run the
application in a processor set comprising only processors that run at
the same speed (see processor_sets(4))
OPERANDS
statistic
The name of an event that your particular Alpha hardware can profile,
as detailed in the STATISTICS section, below. If no statistic is named,
machine cycles are counted, giving a CPU-time profile. One statistic
can be specified for each of the hardware counters on your machine.
program
The name of the executable to run while profiling operations are being
performed.
argument
An argument to pass to the program that is run. Multiple arguments can
be specified, as needed by the program.
OPTIONS
Options can be abbreviated to three characters, except the prof-options,
which can be abbreviated (usually to one character) as in a prof command.
For example, -qui is interpreted as quiet, but -q is interpreted as -quit.
(See the -display option for the supported prof-options.)
For options that specify a procedure name (proc), C++ procedures can omit
the argument type list, though this will match all overloaded procedures
with that name. To select a specific procedure, specify the full symbol
name (as printed by the nm command). Symbol names containing spaces, *, and
so on must be quoted.
-v Engages verbose mode, which prints some useful information about the
program being profiled.
-quiet
Prevents informational and progress messages from being printed.
-dirname path
Specifies the directory path in which the profiling data file or files
are created.
-[no]pids
[Disables] or enables the addition of the process-id number to the name
of the profiling data file or files.
-all|-each|-one
Specifies which mode to use for profiling on multiprocessor machines.
Using the -all option (the default) aggregates the data for all CPUs
into one umon.out file. Using the -each option collects separate
profiles for each CPU and writes the output into a set of files named
umon.out.n, where n is the CPU number. Using the -one option profiles
only the current CPU. For the -one option to work, the uprofile or
kprofile program must be run using the runon command.
-stride n
Sets the granularity of the sample counts, where n is the number of
consecutive instructions grouped together for each sample count. The
default is -stride 4. The -asm, -heavy, and -lines prof-options need a
separate sample count for each instruction (for their reports to be
precise enough), so these options imply -stride 1. This makes the
output file four times bigger than the default size. The -stride
argument must be a power of two (for example, 1, 2, 4, 8).
-average
Attempts to average samples within basic blocks so that each
instruction within a basic block will show the same number of samples.
Ensures fine grain profiles by setting stride to 1.
-pixie
Produces .Addrs and .Counts files similar to those produced by running
an executable instrumented with pixie (see pixie(1)). Uses cycles0
statistic (freq on EV67) by default. Ensures fine grain profiles by
setting stride to 1.
-k kernel_name
Overrides the name of the kernel to profile. (The default is the booted
kernel.)
-t Enables triggered mode for kprofile. This option sets up all required
information for running the performance counters, but does not invoke
them. See the STATISTICS section for additional information.
-ra Enables PCNTCALLER mode for kprofile. Collects profiling data on the
caller of certain kernel utility routines (for example, bcopy, bzero,
simple_lock), instead of the routine itself.
-display|prof-option...
Runs prof on the resulting profile data file(s). The following prof
options are supported:
-asm
Reports the profile as an annotated disassembly.
-exclude proc
Excludes procedure proc from the profile but includes its CPU time
or other statistic in the total.
-Exclude proc
Excludes procedure proc from the profile and from the total.
-heavy
Profiles source lines, printing those with the highest CPU time or
other statistic first.
-lines
Reports the profile per source line within each procedure.
-merge file
Merges all profile data files into file.
-numbers
Prints each procedure's starting line number.
-only proc
Includes only procedure proc in the profile, but totals all
procedures.
-Only proc
Includes only procedure proc in the profile and in the total.
-procedures
Profiles procedures, printing those with the highest CPU time or
other statistic first.
-quit n [[cum]%]
Truncates the reports after n lines or after (cumulative) n percent
of the whole.
STATISTICS
You specify the statistics that you want to collect for the program being
profiled in one or more statistic operands.
If you specify multiple statistics, uprofile and kprofile accumulate their
results. You cannot then view the results of any single statistic
separately. Because collected data is merged into a single buffer,
interpretation of multiply collected statistics may be difficult.
The Alpha architecture implemented on your machine determines which
statistics can be collected and the number of counters available for
collecting multiple statistics at the same time. The implementation is
indicated by the Alpha chip number, which can be displayed with the show
config console command before booting Tru64 UNIX, or, after booting, by
using the psrinfo -v command, or by calling getsysinfo (GSI_PROC_TYPE).
Also, if the uprofile command is run without arguments, it will show how
many counters and what statistics are available on your machine.
All of the chips in the EV4 family (21064 [EV4], 21064A [EV45], 21066/21068
[LCA4]) have two performance counter registers, each of which can be
separately programmed. The statistics that each counter can collect are
shown in the following table:
_____________________________
Counter0Stats Counter1Stats
_____________________________
0disabled 1disabled
issues dcache
pipedry icache
loads dualissues
pipefrozen mispredicts
branches floatops
cycles intops
PALcycles stores
nonissues novictims
victims
_____________________________
All of the chips in the EV5 family (21164 [EV5], 21164A [EV56], and 21164PC
[PCA56]) have three performance counter registers, each of which can be
separately programmed. Some of the counters are common to all EV5
implementations, some are specific to EV5 and EV56, and some are specific
to PCA56.
The statistics that each of the common EV5 counters can collect are shown
in the following table:
_________________________________________________
Counter0Stats Counter1Stats Counter2Stats
_________________________________________________
0disabled 1disabled 2disabled
cycles0 nonissues longstalls
issues splitissue pcmispredicts
pipedry branchmispredicts
replay icachemisses
singleissues itbmisses
dualissues dcacheldmisses
tripleissues dtbmisses
quadissues ldsmerged
flowchanges ldureplays
intops fullreplays
floatops externalinput
loads cycles2
stores memorybarriers
icacheacc lockedloads
dcacheacc
_________________________________________________
The statistics that each of the EV5- and EV56-specific counters can collect
are shown in the following table:
__________________________________
Counter1Stats Counter2Stats
__________________________________
scacheacc scachemisses
scachereads scachereadmisses
scachewrites1 scachewritemisses
scachevictim scachesharedwrites
bcacheref scachewrites2
bcachevictim bcachemisses
sysreqs systeminvalidates
systemreadrequests
__________________________________
The statistics that each of the PCA56-specific counters can collect are
shown in the following table:
_________________________________________
Counter1Stats Counter2Stats
_________________________________________
bcachereads bcachedreads
bcachedreadhits bcachereadhits
bcachedreadfills bcachereadfills
bcachewrites bcachewritehits
bcachecleanwritehits bcachewritefills
bcachevictims sysreadflushhits
readmisstwo sysreadflushmisses
readmissthree
_________________________________________
The EV6 chip has two performance counter registers, each of which can be
separately programmed. The statistics that each of the EV6-specific
counters can collect are shown in the following table:
_____________________________
Counter0Stats Counter1Stats
_____________________________
0disabled 1disabled
cycles0 cycles1
retinst retcondbranch
retdtb1miss
retdtb2miss
retitbmiss
retunaltrap
replay
_____________________________
The default is to gather cycle statistics in the 0th counter and to disable
other counters.
The EV67 chip has two kinds of performance counters: traditional aggregate
counters and profile-me counters. The traditional aggregate statistics that
each of the EV67-specific counters can collect are shown in the following
table. Any one statistic or statistic combination may be selected.
_____________________________
Counter0Stats Counter1Stats
_____________________________
0disabled 1disabled
cycles0 replay
retinst cycles1
retinst bcachemisses
_____________________________
If no aggregate statistics are selected, one profile-me statistic may be
selected:
_____________________________________________________________________________
Profile-me Statistics
_____________________________________________________________________________
2disabled abort abort_per_ret arith_trap
cbr_taken cbr_taken_per_ret cycles cycles_per_ret
delay delay_per_ret dstream_fault dtb_miss
dtb_miss_per_ret dtb_miss3 dtb_miss4 early_kill
early_kill_per_ret fp_disabled freq icache_miss
icache_parity inflt_bcache inflt_replays
icache_miss_per_ret
inflt_retires interrupt istream_accvio itb_miss
ldst_order ldst_unalign map_stall map_stall_per_ret
mispredict opcdec replay_trap
mispredict_per_ret
retire trap trap_per_ret
replay_trap_per_ret
valid
_____________________________________________________________________________
The default is to gather cycle statistics in the 0th counter and to disable
other counters.
For descriptions of the statistics for all EV4, EV5, and EV6
implementations, refer to pfm(7).
You can disable any counter by specifying 0disabled, 1disabled, or
2disabled as the counter statistic. You can use this feature to isolate
specific event types, such as loads, without extraneous data being
generated. You cannot disable all counters at the same time, choose two
statistics for the same counter, or disable a counter once its statistic is
specified.
When you specify no counter statistics, uprofile and kprofile count cycles
on counter 0 by default, and display (through prof) a profile in terms of
seconds used by each procedure in the program, except for any shared
libraries.
For noncycle statistics, the displayed profile shows the number of samples
recorded, the sampling interval (events per second), and the total number
of events that this implies. Most noncycle statistics of the EV5 family
CPUs are recorded about six cycles after the instruction that triggered the
sample. So, when using prof's -asm or -lines option, the samples should be
associated with one of the previously executed few instructions of lines.
The icacheacc, icachemisses, and dtbmisses statistics are usually
attributed precisely.
To perform a detailed analysis of short sections of kernel code, use the
kprofile command with triggered mode (invoked with the -t option). When you
use this mode, kprofile performs all of the required setup for enabling the
counters as normal, but does not invoke them. You can insert counter start
or stop commands into the kernel code to be instrumented as follows:
Turn counters on: wrperfmon (PFOPT, 1)
Turn counters off: wrperfmon (0)
You can turn the counters on and off repeatedly to collect data over many
iterations or multiple sections of code.
The macro PFOPT is defined in <sys/pfcntr.h>.
NOTES
The interrupt load that profiling places on the system may affect
performance, but usually the effect is insignificant.
The kernel in use must have the pfm pseudo-device configured into it. To do
this, use one of the following methods:
· Add the following line to the kernel configuration file, and rebuild
the kernel. Do not use this method if CPU hot-swap is supported by the
system, because it does not allow pfm to be easily unconfigured, as
required for a hot-swap; instead, use the sysconfig method below.
pseudo-device pfm
· Enter the following command from the root account. Do not configure
pfm if CPU hot-swap is anticipated.
# sysconfig -c pfm
If pfm is configured, the CPU hot-swap procedure requires that it be
unconfigured, using the following command, before any CPU is swapped:
# sysconfig -u pfm
The autosysconfig program can be used to automatically load the
configurable pfm device at each system startup.
The format of the data files produced by uprofile in Tru64 UNIX is
different from the format produced in versions of DIGITAL UNIX prior to
Version 4.0. The Tru64 UNIX data files include the names of selected
statistics in profile displays. To convert these data files to the
industry-standard format, at the expense of losing the names of the
statistics, use the pdtostd command.
RESTRICTIONS
The EV4 victim and novictim statistics rely on the external performance
counter pin connections as described in the EV4 chip specification. The DEC
3000/400, /500, /600, and /800 workstations have these connections.
Attempts to display either of these statistics on other platforms (while
allowed) will typically generate empty data.
The uprofile command is only supported on EV4 Pass 3 or later processors.
Attempts to use it on a Pass 2 processor will gather PC samples for every
process running on the system.
Using kprofile to generate statistics for a single command is only possible
on EV4 Pass 3 or later processors. Attempts to do this on a Pass 2
processor will gather statistics for the entire system, as if no command
had been specified.
Using kprofile with triggered mode also requires an EV4 Pass 3 or later
processor and cannot be performed with per-process monitoring.
Only one tool can use the performance counters at a time. A message similar
to "the counter device is busy" indicates that some other tool is using the
performance counters (or has used them but not cleaned up properly). If you
are sure no one else is using the performance counters, running
uprofile/kprofile with superuser privilege will attempt to reset the busy
status and proceed.
FILES
/dev/pfcntr
The performance counter device file.
umon.out[.n]
The statistics file(s) generated by uprofile.
kmon.out[.n]
The statistics file(s) generated by kprofile.
pid.program[.n]
The statistics file(s) generated with the -pids option.
/vmunix
The default kernel to profile.
SEE ALSO
Introduction: prof_intro(1)
pdtostd(1), pfm(7), prof(1), runon(1), psrinfo(1), sysconfig(8),
autosysconfig(8), processor_sets(4)
Programmer's Guide
|
Index for
Section 1 |
|
|
Alphabetical
listing for U |
|
 |
Top of
page |
|