uprofile(1) General Commands Manual 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
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 spec-
ify 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 control-
ling 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
OPERANDS
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. The name of the executable to run while profiling operations are being performed. 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 con-
taining spaces, *, and so on must be quoted. Engages verbose mode, which prints some useful information about the program being profiled.
Prevents informational and progress messages from being printed. Specifies the directory path in which the profiling data file or files
are created. [Disables] or enables the addition of the process-id number to the name of the profiling data file or files. 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 pro-
gram must be run using the runon command. 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). 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. Produces and 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. Overrides the name of the kernel to profile. (The
default is the booted kernel.) Enables triggered mode for kprofile. This option sets up all required information for running the perfor-
mance counters, but does not invoke them. See the STATISTICS section for additional information. 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. Runs prof on the resulting profile data file(s). The following prof options are supported: Reports the profile as an annotated
disassembly. Excludes procedure proc from the profile but includes its CPU time or other statistic in the total. Excludes procedure proc
from the profile and from the total. Profiles source lines, printing those with the highest CPU time or other statistic first. Reports
the profile per source line within each procedure. Merges all profile data files into file. Prints each procedure's starting line number.
Includes only procedure proc in the profile, but totals all procedures. Includes only procedure proc in the profile and in the total.
Profiles procedures, printing those with the highest CPU time or other statistic first. 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 statis-
tic 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-spe-
cific 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 sta-
tistics 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_miss_per_ret icache_parity inflt_bcache inflt_replays
inflt_retires interrupt istream_accvio itb_miss
ldst_order ldst_unalign map_stall map_stall_per_ret
mispredict mispre- opcdec replay_trap
dict_per_ret
replay_trap_per_ret retire trap 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 instruc-
tion 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 (the previous method automatically adds this line without requiring you to manually
edit the file):
pseudo-device pfm Enter the following command from the root account: # sysconfig -c 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 plat-
forms (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
The performance counter device file. The statistics file(s) generated by uprofile. The statistics file(s) generated by kprofile. The
statistics file(s) generated with the -pids option. The default kernel to profile.
SEE ALSO
prof_intro(1), pdtostd(1), pfm(7), prof(1), runon(1), psrinfo(1), sysconfig(8), autosysconfig(8)
Programmer's Guide
uprofile(1)