SHARK4(1) BSD General Commands Manual SHARK4(1)
NAME
shark -- creates *.mshark profiles of system or process behavior for
viewing with Shark.app.
SYNOPSIS
shark [-1] [-a process] [-b] [-c index] [-d path] [-e] [-f file] [-G]
[-g] [-i] [-I interval] [-l] [-L] [-m file] [-N] [-o basename] [-q]
[-r] [-S limit] [-t] [-T limit] [-u] [-v] [-x] [executable
[args...]]
DESCRIPTION
shark helps you tune and understand your code for optimal performance.
At the simplest level, shark profiles the system to see how time is being
spent. It can also produce profiles of hardware and software performance
events such as cache misses, virtual memory activity, instruction depen-
dency stalls, system traces, and other types of profiles. Using these
profiles, you can focus your optimization efforts on performance-critical
code.
shark creates a profile of execution behavior by periodically interrupt-
ing each processor in the system and sampling the currently running
process, thread and instruction address. Along with this contextual
information, shark records the values of the available hardware and soft-
ware performance counters. Each performance counter is capable of count-
ing a wide variety of performance events. In the case of processor and
memory controller counters, these include detailed, low-level information
that is otherwise impossible to know without a simulator.
The profiles generated by shark are statistical in nature; they give a
representative view of what was running on the system during a sampling
session. Samples can include all of the processes running on the system
from both user and supervisor code.
Sampling is controlled by:
Immediately (-i option) - sampling begins immediately and ends when
either the current max sample limit is reached or the launched/attached
target process exits
Hotkey - option-esc to start/stop sampling, ctrl-esc to quit (available
only to the currently logged in user)
Remote - (-r option) - There are several ways to toggle profiling when
shark is in 'remote' mode. 1: A CHUD remote client program can be instru-
mented with calls to: chudStartRemotePerfMonitor()/chudStopRemotePerfMon-
itor() to start/stop sampling. 2: The utility chudRemoteCtrl(1) can be
used on the command line of a terminal to start or stop the collection of
performance monitor samples. 3: The UNIX signals SIGUSR1 and SIGUSR2 can
be sent to shark via its process id (pid) number, to start or stop per-
formance monitoring. Sending the SIGUSR1 signal toggles the start and
stop of sampling. Sending a SIGUSR2 stops sampling and causes a session
file to be generated if need be. When you are using shark over a remote
shell (rlogin, telnet, ssh, etc.) connection, you will need to run shark
and the chudRemoteCtrl(1) utility in the same session (remote shell). The
UNIX signal method is the most reliable. And it works from a separate
shell logged into the same account as the shell running shark In fact the
chudRemoteCtrl(1) utility can send the appropriate UNIX signals to shark
from a separate shell. But the most direct way to send UNIX signals is by
using the kill(1) utility:
for example: % kill -s USR1 <pid>
% chudRemoteCtrl -s <session_name> -k<pid>
will start sampling using SIGUSR1; and
% chudRemoteCtrl -e -k<pid>
will stop sampling using SIGUSR2, which also creates the session file
(if any).
Profiling over a remote shell works very well if you have shark launch an
executable that has been instrumented with the CHUD functions. Typical
instrumentation might look like:
//add the header file
#include <CHUD/CHUD.h>
//then in the main...
chudInitialize();
chudAcquireRemoteAccess();
//just before the code to be profiled
chudStartRemotePerfMonitor("some run label");
//just after the code to be profiled
chudStopRemotePerfMonitor();
//before the program exits:
chudReleaseRemoteAccess();
Network Sharing (-N option) - a message is sent to the shark program,
from another computer on the network, to toggle profiling. Typically, one
system, on the network, is running Shark.app. The Shark.app program will
have been configured to manage other profiling "service" programs. shark
is a profiling service program when the '-N' option is given on the com-
mand line. In network sharing mode shark can still be triggered by sig-
nals and by hotkeys on the local host. The sessions generated by shark
will be cached and delivered to the controlling Shark application when
the Shark application requests the session file, or as soon as it is
available, if the Shark application requests automatic delivery of ses-
sions from the profiling services. One shark program can be run on each
of many systems on the network. One system running Shark.app can control
profiling on all of the systems running shark simultaneously.
OPTIONS
-1 Sample only the target process (specified through -a process
or the launched executable).
-a process Attach to a currently running process with the specified name
or PID. If a process is not given, shark can also optionally
launch a new process from a specified executable. If neither
-a process or an executable is specified, shark will wait for
further input (either a the start/stop hotkey, option-esc, or
a CHUD remote monitoring start message if remote monitoring
is enabled).
-b Enable batch mode. By default, shark will exit after record-
ing a single *.mshark session file. This option allows you
to record multiple sessions without exiting shark.
-c index Specifies the index of the sampling configuration to be used.
-d path Sets the directory file path name used for *.mshark session
files. By default this is not set to anything. So shark gen-
erates session files in the current working directory. No
directories are created by shark. NOTE: If a directory path
is set with this option, then including a slash (/) as the
first component of the basename argument (to the '-o' option,
above) will generate a fatal error.
-e List the current settings of search-path environment vari-
ables used by shark to locate various types of files during
session processing. There are currently two environment
variables: SHARK_SEARCH_PATH_KEXT_FILES and
SHARK_SEARCH_PATH_SOURCE_FILES. shark will search the colon
delimited lists of file paths for Kernel Extensions and
Source Files, respectively. NOTE: Even if no search paths
are specified for Kernel Extensions
(SHARK_SEARCH_PATH_KEXT_FILES) some paths will be listed;
shark adds to these paths automatically.
-f file Specifies the path to an executable, or (MachO) object file
to be statically analyzed. This file is used in conjunction
with a shark -Static Analysis- config file. The config file
must be specified with the '-c' or '-m' options.
-G Create a brief textual report from each analysis module that
is active in the profiling config. If an analysis module
does not support plain text reporting a "<NO REPORT AVAIL-
ABLE>" message is printed. The text report will have the
same name as the session except the extension will be
"...-report.txt" instead of ".mshark"
-g session file name(s)
Create a brief textual report from any analysis modules that
are active in each session file named on the command line.
If an analysis module does not support plain text reporting a
"<NO REPORT AVAILABLE>" message is put in the report. The
text report will have the same name as the related session
file except the extension will be "...-report.txt" instead of
".mshark"
-i Begin sampling immediately, exiting after a session has been
taken.
-I interval
Change the per-sample time interval to this value. Enter the
value as a number followed by a suffix: for example 5m would
set the per-sample time interval to 5 milliseconds. 50u
would change the per-sample time limit to 50 microseconds. 5s
would change the per-sample time limit to 5 seconds.
-l Lists the available sampling configurations and exits. New
sampling configurations can be created with Shark.app (the
GUI version of shark ). shark looks for user configurations
in ~/Library/Application Support/Shark/Configs.
-L Similar to -l option, but adds detailed description of each
configuration.
-m file Specifies the path to a shark sampling config (*.cfg) file to
be used.
-N Enables Network Sharing mode in the shark program. Enabling
network sharing does not disable any of the other methods for
starting and stopping profiling.
-o basename
Sets the basic file name used for *.mshark session files. By
default this is "session", which generates session files
named session_{x}.mshark in the current working directory.
The 'basename' can contain relative path information, or
absolute path information if the '-d' option is not specified
on the command line. shark will honor the file path speci-
fied before the basename, provided ALL the directories in the
path exist already. No directories are created by shark.
-q Quiet mode. Runs silently (no output to terminal) unless an
error is encountered.
-r Enable remote monitoring mode. In this mode shark waits for a
CHUD remote client program to call chudStartRemotePerfMoni-
tor()/chudStopRemotePerfMonitor() to start and stop sampling.
(see above for more details on this option)
-S limit Change the sample limit to this <limit> number of samples.
-t [session file name(s)]
Create a text output file representing the complete analysis
from the session for each analysis module active in the ses-
sion. Note that not every analysis module supports full-text
output. If a module does not support full-text output, the
phrase:
<FULL-TEXT FORMAT NOT AVAILABLE> appears in the text file for
that module. The full-text output file will have the same
name as the session except the extension will be
"...-full.txt" instead of ".mshark".
Session file names are optional; if omitted, full text
reports will be generated for each session you take. If
included, no session will be taken - instead, text reports
will be generated from the given session file names.
The '-t' option and the '-G' option can both be used at the
same time, since they create different filenames.
-T limit Change the maximum time limit to this value. Enter the value
as a number followed by a suffix: for example 500m would set
the time limit to 500 milliseconds. 500000u would change the
time limit to 500000 microseconds. 22s would change the sam-
pling time limit to 22 seconds.
-u Identify processes by name (the default behavior is to iden-
tify processes by PID).
-v Prints the Shark version and exits.
-w After stopping sampling, wait until the user presses Return
before creating the session file.
-x Ignore task will exit notifications. Normally shark will be
notified whenever a process (task) exits while it is sam-
pling. This allows for all relevant symbol and other infor-
mation required for later analysis to be gathered before
allowing the exiting task to complete exiting. The process-
ing that occurs during a task exit notification can cause
gaps in the resulting profile.
BUGS
Please send your comments, suggestions and bug reports to: perftools-
feedback@group.apple.com
SEE ALSO
chudRemoteCtrl(1), kill(1), /Developer/Documenta-
tion/CHUD/Shark/SharkUserGuide.pdf
September 17, 2009
Mac OS X 10.6 - Generated Thu Sep 17 20:09:09 CDT 2009