examples: add pf3.stp

[systemtap.git] / testsuite / systemtap.examples / index.txt

SYSTEMTAP EXAMPLES INDEX
(see also keyword-index.txt)

general/ansi_colors.stp - Color Table for ansi_set_color2() and ansi_set_color3()
keywords: format

  The script prints a table showing the available color combinations
  for the ansi_set_color2() and ans_set_color3() functions in the
  ansi.stp tapset.

  # stap ansi_colors.stp


general/ansi_colors2.stp - Show Attribues in Table for ansi_set_color3()
keywords: format

  The script prints a table showing the available attributes (bold,
  underline, and inverse) with color combinations for the
  ans_set_color3() function in the ansi.stp tapset.

  # stap ansi_colors2.stp


general/badname.stp - Bad Filename Filter
keywords: filesystem

  The badname.stp script shows how one could prevent the creation of
  files with undesirable names using guru mode.

  # stap -g badname.stp -c "touch /tmp/myXXXbadnameXXXfile.$$ 2>&1 | grep \
  denied"


general/eventcount.stp - Count Specified Events
keywords: statistics thread process

  The script prints a count of specified events and their related tid's
  over the course of execution.

  # stap eventcount.stp syscall.* -c 'sleep 0.2'


general/func_time_stats.stp - Function Time Statistics
keywords: function statistics

  The func_time_stats.stp script tracks the wall clock time for each
  invocation of the function probe listed as the first command line
  argument. When the script exits it prints out the minimum, average,
  and maximum times in microseconds followed by a count of times that
  the function was called and a histogram showing the distributions of
  times.

  # stap func_time_stats.stp 'syscall.nanosleep' -c "sleep 0.2"


general/graphs.stp - Graphing Disk and CPU Utilization
keywords: disk cpu utilization

  The script tracks the disk and CPU utilization. The resulting output
  of the script can be piped into gnuplot to generate a graph of disk
  and CPU USE.

  # stap graphs.stp -c "sleep 0.2"


general/helloworld.stp - SystemTap "Hello World" Program
keywords: simple

  A basic "Hello World" program implemented in SystemTap script. It
  prints out "hello world" message and then immediately exits.

  # stap helloworld.stp


general/para-callgraph-verbose.stp - Callgraph Tracing with Verbose Arguments
keywords: trace callgraph

  Print a timed per-thread callgraph, complete with pretty-printed
  function parameters and return values.  The first parameter names the
  function probe points to trace.  The optional second parameter names
  the probe points for trigger functions, which acts to enable tracing
  for only those functions that occur while the current thread is
  nested within the trigger.

  # stap para-callgraph-verbose.stp 'kernel.function("*@fs/proc*.c")' \
  'kernel.function("vfs_read")' -c "cat /proc/sys/vm/* || true"


general/para-callgraph.stp - Callgraph Tracing with Arguments
keywords: trace callgraph

  Print a timed per-thread callgraph, complete with function parameters
  and return values.  The first parameter names the function probe
  points to trace.  The optional second parameter names the probe
  points for trigger functions, which acts to enable tracing for only
  those functions that occur while the current thread is nested within
  the trigger.

  # stap para-callgraph.stp 'kernel.function("*@fs/proc*.c")' \
  'kernel.function("vfs_read")' -c "cat /proc/sys/vm/* || true"


general/sizeof.stp - Print the Size of a C Type
keywords: statistics memory

  This script prints the size of a type, based on dwarf debuginfo for
  any kernel or userspace module, or trial-compilation of a given
  header file name.

  # stap sizeof.stp FILE '</usr/include/stdio.h>'


general/stopwatches.stp - See the amount of wall clock time a process spends in various states
keywords: time

  The stopwatch.stp script illustrates how to use multiple stopwatches
  record how much wallclock time a process spends in kernel- and
  user-space.  On exit the script prints out the time in seconds,
  milliseconds, microseconds, and nanoseconds. Note that this output of
  this script is not directly comparable to the time command because
  time records the time that the process is actually active in kernel-
  and user-space.

  # stap stopwatches.stp -c "sleep 0.2"


general/varwatch.stp - Watch a Variable Changing Value in a Thread
keywords: monitoring

  This script places a set of probes (specified by $1), each of which
  monitors the state of some context $variable expression (specified by
  $2).  Whenever the value changes, with respect to the active thread,
  the event is traced.

  # stap -w varwatch.stp 'kernel.statement("do_sys_open@fs/open.c:*")' \
  '$$vars' -c "sleep 0.2"


general/watchdog.stp - Watchdog Timer for Arbitrary Events
keywords: watchdog backtrace

  The watchdog.stp script provides a watchdog timer mechanism for
  arbitrary events. The script takes three arguments: the events to
  start watchdog timer, the event to stop the watchdog timer, and the
  time in millseconds for the watchdog. If the watchdog timer is
  exceed, the script will trigger a stack backtrace of the user-process
  that timed out using pstack. This script can be used to diagnose what
  the userspace application is doing when a slower than expected
  operation occurs.

  # stap watchdog.stp 'syscall.nanosleep' 'syscall.nanosleep.return' 1000 \
  -c "sleep 0.2"


interrupt/interrupts-by-dev.stp - Record Interrupts on a Per-Device Basis
keywords: interrupt

  The interrupts-by-dev.stp script profiles interrupts received by each
  device per 100 ms.

  # stap interrupts-by-dev.stp -c "sleep 0.2"


interrupt/scf.stp - Tally Backtraces for Inter-Processor Interrupt
keywords: interrupt backtrace

  The Linux kernel function smp_call_function causes expensive
  inter-processor interrupts (IPIs). The scf.stp script tallies the
  processes and backtraces causing the interprocessor interrupts to
  identify the cause of the expensive IPI. On exit the script prints
  the tallies in descending frequency.

  # stap scf.stp -c "sleep 0.2"


io/deviceseeks.stp - Histograms of Seek Behavior for Each Device
keywords: disk

  The deviceseeks.stp script generates a histogram showing the
  frequency of different sized seeks on each device.

  # stap deviceseeks.stp -c "sleep 0.2"


io/disktop.stp - Summarize Disk Read/Write Traffic
keywords: disk

  Get the status of reading/writing disk every 5 seconds, output top
  ten entries during that period.

  # stap disktop.stp -c "sleep 0.2"


io/enospc.stp - Report an disk out-of-space condition.
keywords: disk filesystem

  This script monitors a filesystem implementations for early internal
  indications of ENOSPC, and reports these to the system logger and the
  systemtap console.

  # stap enospc.stp -c "sleep 0.2"


io/inodewatch.stp - Monitoring Reads and Writes to a File
keywords: io

   The inodewatch.stp outputs the executable name and process id each
  time a read or write occurs to the specified inode on the specified
  major/minor device.

  # stap inodewatch.stp 0x08 0x01 100 -c "sleep 0.2"


io/inodewatch2.stp - Monitoring Attribute Changes to a File
keywords: io

   The inodewatch2.stp script outputs the executable name, process id,
  and attributes each time the attributes are changed on the specified
  inode on the specified major/minor device.

  # stap inodewatch2.stp 0x08 0x01 100 -c "sleep 0.2"


io/io_submit.stp - Tally Reschedule Reason During AIO io_submit Call
keywords: io backtrace

  When a reschedule occurs during an AIO io_submit call, accumulate the
  traceback in a histogram. When the script exits prints out a sorted
  list from most common to least common backtrace.

  # stap io_submit.stp -c "sleep 0.2"


io/ioblktime.stp - Average Time Block IO Requests Spend in Queue 
keywords: io

  The ioblktime.stp script tracks the amount of time that each block IO
  requests spend waiting for completion. The script computes the
  average waiting time for block IO per device and prints list every 10
  seconds. In some cases there can be too many outstanding block IO
  operations and the script may exceed the default number of
  MAXMAPENTRIES allowed. In this case the allowed number can be
  increased with "-DMAXMAPENTRIES=10000" option on the stap command
  line.

  # stap ioblktime.stp -c "sleep 0.2"


io/iodevstats.stp - List Executables Reading and Writing the Most Data by Device
keywords: io profiling

   The iodevstats.stp script measures the amount of data successfully
  read and written by all the executables for each io device on the
  system.  The output is sorted from greatest sum of bytes read and
  written to a device by an executable to the least. The output
  contains device major/minor number, the count of operations (reads
  and writes), the totals and averages for the number of bytes read and
  written.

  # stap iodevstats.stp -c "sleep 0.2"


io/iostat-scsi.stp - IO Statistics for SCSI Devices
keywords: io profiling scsi

  The iostat-scsi.stp script provides a breakdown of the number of blks
  read and written on the machine's various SCSI devices. The script
  takes one argument which is the number of seconds between reports.

  # stap -g iostat-scsi.stp 1 -c "sleep 0.2"


io/iostats.stp - List Executables Reading and Writing the Most Data
keywords: io profiling

   The iostat.stp script measures the amount of data successfully read
  and written by all the executables on the system.  The output is
  sorted from most greatest sum of bytes read and written by an
  executable to the least. The output contains  the count of operations
  (opens, reads, and writes), the totals and averages for the number of
  bytes read and written.

  # stap iostats.stp -c "sleep 0.2"


io/iotime.stp - Trace Time Spent in Read and Write for Files 
keywords: profiling syscall io file

  The script watches each open, close, read, and write syscalls on the
  system. For each file the scripts observes opened it accumulates the
  amount of wall clock time spent in read and write operations and the
  number of bytes read and written. When a file is closed the script
  prints out a pair of lines for the file. Both lines begin with a
  timestamp in microseconds, the PID number, and the executable name in
  parentheses. The first line with the "access" keyword lists the file
  name, the attempted number of bytes for the read and write
  operations. The second line with the "iotime" keyword list the file
  name and the number of microseconds accumulated in the read and write
  syscalls.

  # stap iotime.stp -c "sleep 0.2"


io/iotop.stp - Periodically Print IO Activity by Process Name
keywords: io

  Every five seconds print out the top ten executables generating I/O
  traffic during that interval sorted in descending order.

  # stap iotop.stp -c "sleep 0.2"


io/mbrwatch.stp - Monitor Read/Write of the Boot Sector Area of Block Devices
keywords: io monitoring disk

   The mbrwatch.stp script reports any attempted reads/writes of the
  first few sectors of a raw block device.

  # stap mbrwatch.stp -c "dd of=/dev/null count=1 if=/dev/`grep -v major \
  /proc/partitions | grep . | awk '{print $4}' | head -1`"


io/nfs_func_users.stp - Tally the Number of NFS Functions Used by Each Process
keywords: io profiling

  The nfs_func_users.stp script counts the uses of NFS functions in the
  kernel on a per process bases.  The output is sorted from the process
  with the greatest number of NFS functions called to the least. The
  output contains the executable name, the process number, and the
  total number of NFS functions called by the process.

  # stap nfs_func_users.stp -c "sleep 0.2"


io/traceio.stp - Track Cumulative IO Activity by Process Name
keywords: io

  Every second print out the top ten executables sorted in descending
  order based on cumulative I/O traffic observed.

  # stap traceio.stp -c "sleep 0.2"


io/traceio2.stp - Watch IO Activity on a Particular Device
keywords: io

  Print out the executable name and process number as reads and writes
  to the specified device occur.

  # stap traceio2.stp 0x0801 -c "sleep 0.2"


io/ttyspy.stp - Monitor TTY Typing
keywords: io tty monitoring

  The ttyspy.stp script uses tty_audit hooks to monitor recent typing
  activity on the system, printing a scrolling record of recent
  keystrokes, on a per-tty basis.

  # stap --skip-badvars -g ttyspy.stp -c "sleep 1"


locks/bkl.stp - Tracing Contention on Big Kernel Lock
keywords: locking

  The bkl.stp script can help determine whether the Big Kernel Lock
  (BKL) is causing serialization on a multiprocessor system due to
  excessive contention of the BKL. The bkl.stp script takes one
  argument which is the number of processes waiting for the Big Kernel
  Lock (BKL). When the number of processes waiting for the BKL is
  reached or exceeded, the script will print a time stamp, the number
  of processes waiting for the BKL, the holder of the BKL, and the
  amount of time the BKL was held.

  # stap bkl.stp -c "sleep 0.2" 1


locks/bkl_stats.stp - Per Process Statistics on Big Kernel Lock Use
keywords: locking

  The bkl_stats.stp script can indicate which processes have excessive
  waits for the Big Kernel Lock (BKL) and which processes are taking
  the BKL for long periods of time. The bkl_stats.stp script prints
  lists of all the processes that require the BKL. Every five seconds
  two tables are printed out. The first table lists the processes that
  waited for the BKL followed by the number of times that the process
  waited, the minimum time of the wait, the average and the maximum
  time waited. The second table lists has similar information for the
  time spent in holding the lock for each of the processes.

  # stap bkl_stats.stp -c "sleep 0.2"


memory/hw_watch_addr.stp - Watch a Kernel Address Using Breakpoint Hardware
keywords: memory watchpoint

  The script will watch accesses to a single kernel address and prints
  a traceback each time the address is accessed. This script needs to
  be run as root to allow access to the breakpoint hardware.

  # stap --all-modules hw_watch_addr.stp 0x`grep "pid_max$" /proc/kallsyms` \
  -c "sleep 1"


memory/hw_watch_sym.stp - Watch a Kernel Symbol Using Breakpoint Hardware
keywords: memory watchpoint

  The script will watch accesses to the starting address of a single
  kernel symbol and prints a traceback each time the symbol is
  accessed. This script needs to be run as root to allow access to the
  breakpoint hardware.

  # stap --all-modules hw_watch_sym.stp pid_max -c "sleep 1"


memory/kmalloc-top - Show Paths to Kernel Malloc Invocations
keywords: memory

  The kmalloc-top perl program runs a small systemtap script to collect
  stack traces for each call to the kmalloc function and counts the
  time that each stack trace is observed. When kmalloc-top exits it
  prints out sorted list. The output can be filtered to print only the
  first N stack traces (-t), stack traces with a minimum counts (-m),
  or exclude certain stack traces (-e).

  # ./kmalloc-top -c "sleep 0.2"


memory/mmanonpage.stp - Track Virtual Memory System Actions on Anonymous Pages
keywords: memory

  The mmanonpage.stp script uses the virtual memory tracepoints
  available in some kernels to track the number of faults, user space
  frees, page ins, copy on writes and unmaps for anonymous pages. When
  the script is terminated the counts are printed for each process that
  allocated pages while the script was running. This script displays
  the anonymous page statistics for each process that ran while the
  script is active.  It's useful in debugging leaks in the anonymous
  regions of a process.

  # stap mmanonpage.stp -c "sleep 0.2"


memory/mmfilepage.stp - Track Virtual Memory System Actions on File Backed Pages
keywords: memory

  The mmfilepage.stp script uses the virtual memory tracepoints
  available in some kernels to track the number of faults, copy on
  writes mapping, and unmapping operations for file backed pages. When
  the script is terminated the counts are printed for each process that
  allocated pages while the script was running. The mmfilepage.stp
  script is useful in debugging leaks in the mapped file regions of a
  process.

  # stap mmfilepage.stp -c "sleep 0.2"


memory/mmreclaim.stp - Track Virtual Memory System Page Reclamation
keywords: memory

  The mmreclaim.stp script uses the virtual memory tracepoints
  available in some kernels to track page reclaim activity that
  occurred while the script was running. It's useful in debugging
  performance problems that occur due to page reclamation.

  # stap mmreclaim.stp -c "sleep 0.2"


memory/mmwriteback.stp - Track Virtual Memory System Writing to Disk
keywords: memory

  The mmwriteback.stp script uses the virtual memory tracepoints
  available in some kernels to report all of the file writebacks that
  occur form kupdate, pdflush and kjournald while the script is
  running.  It's useful in determining where writes are coming from on
  a supposedly idle system that is experiencing unexpected IO.

  # stap mmwriteback.stp -c "sleep 0.2"


memory/numa_faults.stp - Summarize Process Misses across NUMA Nodes
keywords: memory numa

  The numa_faults.stp script tracks the read and write pages faults for
  each process. When the script exits it prints out the total read and
  write pages faults for each process. The script also provide a break
  down of page faults per node for each process. This script is useful
  for determining whether the program has good locality (page faults
  limited to a single node) on a NUMA computer.

  # stap numa_faults.stp -c "sleep 0.2"


memory/overcommit.stp - Log Failed Process Memory Allocation Due to Overcommit Limits
keywords: memory limits

  The overcommit.stp script prints a line each time the kernel refuses
  a memory allocation request from a process because of
  /proc/sys/vm/overcommit* limits.

  # stap overcommit.stp -c "sleep 0.2"


memory/pfaults.stp - Generate Log of Major and Minor Page Faults
keywords: memory

  The pfaults.stp script generates a simple log for each major and
  minor page fault that occurs on the system. Each line contains a
  timestamp (in microseconds) when the page fault servicing was
  completed, the pid of the process, the address of the page fault, the
  type of access (read or write), the type of fault (major or minor),
  and the elapsed time for page fault. This log can be examined to
  determine where the page faults are occurring.

  # stap pfaults.stp -c "sleep 0.2"


memory/vm.tracepoints.stp - Collect Slab Allocation Statistics
keywords: memory slab statistics

  The script will probe all memory slab/slub allocations and collects
  information about the size of the object (bytes requested) and
  user-space process in execution. When run over a period of time, it
  helps to correlate kernel-space memory consumption owing to
  user-space processes.

  # stap vm.tracepoints.stp -c "sleep 10"


network/autofs4.stp - Watch autofs4 Operations
keywords: network autofs nfs

  Trace key autofs4 operations such as mounting or unmounting remote
  filesystems.

  # stap autofs4.stp -c "sleep 1"


network/dropwatch.stp - Watch Where Socket Buffers Are Freed in the Kernel
keywords: network tracepoint socket

  Every five seconds the dropwatch.stp script lists the number of
  socket buffers freed at locations in the kernel.

  # stap dropwatch.stp -c "sleep 0.2"


network/netdev.stp - Trace Activity on Network Devices
keywords: network device traffic

  The netdev.stp script traces configuration and transmit/receive
  activity on network devices.

  # stap netdev.stp -c "sleep 0.2"


network/nettop.stp - Periodic Listing of Processes Using Network Interfaces
keywords: network traffic

  Every five seconds the nettop.stp script prints out a list of
  processed (PID and command) with the number of packets sent/received
  and the amount of data sent/received by the process during that
  interval.

  # stap nettop.stp -c "sleep 0.2"


network/nfsd_unlink.stp - Find Which Client Is Removing NFS Files on Server
keywords: nfs disk

  The nfsd_unlink.stp script lists the ip address and file name each
  time time a file is being removed or unlinked by the nfsd. This
  script is run on the nfs server.

  # stap nfsd_unlink.stp -c "sleep 0.2"


network/sk_stream_wait_memory.stp - Track Start and Stop of Processes Due to Network Buffer Space
keywords: network tcp process

  The sk_stream-wait_memory.stp prints a time stamp, executable, and
  pid each time a process blocks due to the send buffer being full. A
  similar entry is printed each time a process continues because there
  is room in the buffer.

  # stap sk_stream_wait_memory.stp -c "sleep 0.2"


network/socket-trace.stp - Trace Functions Called in Network Socket Code
keywords: network socket

  The script instruments each of the functions in the Linux kernel's
  net/socket.c file. The script prints out trace data. The first
  element of a line is time delta in microseconds from the previous
  entry. This is followed by the command name and the PID. The "->" and
  "<-" indicates function entry and function exit, respectively. The
  last element of the line is the function name.

  # stap socket-trace.stp -c "sleep 0.2"


network/socktop - Periodically Summarize Socket Activity on the System
keywords: network socket

  The socktop script periodically prints out a list of the processes
  with the highest socket activity.  Command line options for the
  script allow filtering to focus on particular types of sockets. The
  "-h" option lists socktop script's filtering options.

  # ./socktop -c 1


network/tcp_connections.stp - Track Creation of Incoming TCP Connections
keywords: network tcp socket

  The tcp_connections.stp script prints information for each new
  incoming TCP connection accepted by the computer. The information
  includes the UID, the command accepting the connection, the PID of
  the command, the port the connection is on, and the IP address of the
  originator of the request.

  # stap tcp_connections.stp -c "sleep 0.2"


network/tcp_init_cwnd.stp - Increase Initial TCP Congestion Window to 10
keywords: network tcp socket

  Run the tcp_init_cwnd.stp script in the background to override a
  kernel's default tcp cwnd value to 10, which has been found to
  improve latency for web server type workloads.  The script prints a
  count of cwnd value changes when it is stopped.

  # stap -g tcp_init_cwnd.stp -c "sleep 0.2"


network/tcp_trace.stp - TCP Connection Tracing Utility
keywords: network trace

  This scripts traces a given TCP connection based on the filter
  parameters given by the user. The indexing is done by the 4 tuples
  local address, remote address, local port, remote port.

  # stap tcp_trace.stp 127.0.0.1:*-127.0.0.1:* timeout=1


network/tcpdumplike.stp - Dump of Received TCP Packets
keywords: network traffic

  The tcpdumplike.stp prints out a line for each TCP packet received.
  Each line includes the source and destination IP addresses, the
  source and destination ports, and flags.

  # stap tcpdumplike.stp -c "sleep 0.2"


network/tcpipstat.stp - Display Network Statistics for Individual TCP Sockets
keywords: network statistics

  The tcpipstat script collects and displays network statistics related
  to individual TCP sockets or groups of sockets.  The statistics that
  are collected are simular to that of the command netstat -s, only
  sorted and grouped by individual sockets.

  # stap tcpipstat.stp timeout=1


process/chng_cpu.stp - Monitor Changes in Processor Executing a Task
keywords: scheduler

  The chng_cpu.stp script takes an argument which is the executable
  name of the task it should monitor. Each time a task with that
  executable name is found running on a different processor, the script
  prints out the thread id (tid), the executable name, the processor
  now running the task, the thread state, and a backtrace showing the
  kernel functions that triggered the running of the task on the
  processor.

  # stap chng_cpu.stp -c "sleep 0.2" bash


process/cycle_thief.stp - Track IRQ's and Other Processes Stealing Cycles from a Task
keywords: process scheduler time tracepoint interrupt

  The cycle_thief.stp script instruments the scheduler and IRQ handler
  to determine which processes and interrupts are competing with the
  specified task for the cpu cycles. This script uses the '-c' or '-x'
  options to focus on a specific task. The script output the number of
  times the task migrates between processors, histograms showing the
  length of time on and off processor, lists of processes running while
  the task is off the processor, and the interrupts that occurred while
  the task was running.

  # stap cycle_thief.stp -c "sleep 0.2"


process/errsnoop.stp - Tabulate System Call Errors
keywords: process syscall

  Prints a periodic tabular report about failing system calls, by
  process and by syscall failure.  The first optional argument
  specifies the reporting interval (in seconds, default 5); the second
  optional argument gives a screen height (number of lines in the
  report, default 20).

  # stap errsnoop.stp 1 10 -c "sleep 1"


process/forktracker.stp - Trace Creation of Processes
keywords: process scheduler

  The forktracker.stp script prints out a time-stamped entry showing
  each fork and exec operation on the machine. This can be useful to
  determine what process is creating a flurry of short-lived processes.

  # stap forktracker.stp -c "sleep 0.2"


process/futexes.stp - System-Wide Futex Contention
keywords: syscall locking futex

  The script watches the futex syscall on the system. On exit the
  futexes address, the number of contentions, and the average time for
  each contention on the futex are printed from lowest pid number to
  highest.

  # stap futexes.stp -c "sleep 0.2"


process/migrate.stp - Track the Migration of Specific Executables
keywords: scheduler

  The migrate.stp script takes an argument which is the executable name
  of the task it should monitor. Each time a task with that executable
  name migrates between processors an entry is printed with the process
  id (pid), the executable name, the processor off loading the task,
  and the process taking the task. Note that the task may or may not be
  executing at the time of the migration.

  # stap migrate.stp -c "sleep 0.2" bash


process/noptrace.stp - Disable ptrace from Hierarchies of Processes
keywords: process security

  Blocks ptrace(2) attempts from processes identified by stap -c/-x, as
  also specifiable from /proc/systemtap/stap_XXX/ control files. 
  Processes may be added or removed from the blocked list.

  # stap -g noptrace.stp -c 'strace ls || true'


process/pfiles.stp - Print Process File Descriptors
keywords: process file

  Run pfiles.stp to produce a human-readable summary of all open file
  descriptors of a given process.  Specify the process-id as -x PID for
  fastest performance.

  # stap -g pfiles.stp -x $$


process/plimit.stp - Print Resource Limits of Process
keywords: process

  The script prints a variety of resource limits for a given pid, like
  /proc/$$/limits on recent kernels.

  # stap -g plimit.stp $$


process/pstrace_exec.stp - Print trace of process ancestors for matching exec commands
keywords: process backtrace

  The pstrace_exec.stp script watches each exec operation. If the exec
  contains a substring that matches the script's command-line argument,
  it prints out that process and all of its ancestors.

  # stap pstrace_exec.stp -c "sleep 0.2" bash


process/schedtimes.stp - Track Time Processes Spend in Various States Using Tracepoints
keywords: process scheduler time tracepoint

  The schedtimes.stp script instruments the scheduler to track the
  amount of time that each process spends in running, sleeping,
  queuing, and waiting for io. On exit the script prints out the
  accumulated time for each state of processes observed.  Optionally,
  this script can be used with the '-c' or '-x' options to focus on a
  specific PID.

  # stap schedtimes.stp -c "sleep 0.2"


process/sig_by_pid.stp -  Signal Counts by Process ID
keywords: signals

  Print signal counts by process ID in descending order.

  # stap sig_by_pid.stp -c "sleep 0.2"


process/sig_by_proc.stp -  Signal Counts by Process Name
keywords: signals

  Print signal counts by process name in descending order.

  # stap sig_by_proc.stp -c "sleep 0.2"


process/sigkill.stp - Track SIGKILL Signals
keywords: signals

  The script traces any SIGKILL signals. When that SIGKILL signal is
  sent to a process, the script prints out the signal name, the
  destination executable and process ID, the executable name and user
  ID that sents the signal.

  # stap sigkill.stp -c "sleep 0.2"


process/sigmon.stp - Track a Particular Signal to a Specific Process
keywords: signals

  The script watches for a particular signal sent to a specific
  process. When that signal is sent to the specified process, the
  script prints out the PID and executable of the process sending the
  signal, the PID and executable name of the process receiving the
  signal, and the signal number and name.

  # stap sigmon.stp -c "sleep 0.2" SIGKILL


process/sleepingBeauties.stp - Generate Backtraces of Threads Waiting for IO Operations
keywords: io scheduler backtrace

  The script monitors the time that threads spend in waiting for IO
  operations (in "D" state) in the wait_for_completion function.  If a
  thread spends over 10ms, its name and backtrace is printed, and later
  so is the total delay.

  # stap sleepingBeauties.stp -c "sleep 0.2"


process/sleeptime.stp - Trace Time Spent in Nanosleep Syscalls
keywords: syscall nanosleep

  The script watches each nanosleep syscall on the system. At the end
  of each nanosleep syscall the script prints out a line with a
  timestamp in microseconds, the pid, the executable name in
  parentheses, the "nanosleep:" key, and the duration of the sleep in
  microseconds.

  # stap sleeptime.stp -c "sleep 0.2"


process/syscalls_by_pid.stp - System-Wide Count of Syscalls by PID
keywords: syscall

  The script watches all syscall on the system. On exit the script
  prints a list showing the number of systemcalls executed by each PID
  ordered from greatest to least number of syscalls.

  # stap syscalls_by_pid.stp -c "sleep 0.2"


process/syscalls_by_proc.stp - System-Wide Count of Syscalls by Executable
keywords: syscall

  The script watches all syscall on the system. On exit the script
  prints a list showing the number of systemcalls executed by each
  executable ordered from greatest to least number of syscalls.

  # stap syscalls_by_proc.stp -c "sleep 0.2"


process/syscalltimes - System-Wide Syscall Statistics with Filtering
keywords: syscall

  Combination shell/systemtap script to measure system call counts and
  times.  Can be filtered by process IDs, process names and users.

  # ./syscalltimes -c 'sleep 0.2'


process/wait4time.stp - Trace Time Spent in wait4 Syscalls
keywords: syscall process

  The script watches each wait4 syscall on the system. At the end of
  each wait4 syscall the script prints out a line with a timestamp in
  microseconds, the pid, the executable name in parentheses, the
  "wait4:" key, the duration of the wait and the PID that the wait4 was
  waiting for. If the waited for PID is not specified , it is "-1".

  # stap wait4time.stp -c "sleep 0.2"


profiling/errno.stp - Show Which Processes and System Calls Return Errors Most Frequently
keywords: profiling

  On exit the errno.stp script provides a sorted list showing which
  combination of PID, system call, and error occur most frequently.

  # stap errno.stp -c "sleep 0.2"


profiling/fntimes.stp - Show Functions Taking Longer Than Usual
keywords: profiling

  The fntimes.stp script monitors the execution time history of a given
  function family (assumed non-recursive).  Each time (beyond a warmup
  interval) is then compared to the historical maximum.  If it exceeds
  a certain threshold (250%), a message is printed.

  # stap fntimes.stp 'kernel.function("sys_*")' -c "sleep 7"


profiling/functioncallcount.stp - Count Times Functions Are Called
keywords: profiling function

  The functioncallcount.stp script takes one argument, a list of
  functions to probe. The script will run and count the number of times
  that each of the functions on the list is called. On exit the script
  will print a sorted list from most frequently to least frequently
  called function.

  # stap  functioncallcount.stp "*@mm/*.c" -c "sleep 0.2"


profiling/latencytap.stp - Show Reasons and Durations for Processes Sleeping
keywords: profiling

  The latencytap.stp script collects data on the intervals processes
  are deactivated (sleeping).  The script categorizes the reasons for
  the sleeps by analyzing the backtraces and displays a sorted list of
  the top 20 causes from largest total sum time sleeping to smallest.
  The output is updated every 30 seconds. The script needs to be
  compiled with the '--all-modules' option to produce reasons for
  sleeps caused by modules.  Optionally, this script can be used with
  the '-c' or '-x' options to focus on a specific PID.

  # stap latencytap.stp --all-modules -c "sleep 0.2"


profiling/linetimes.stp - Show Time Spent on Each Line of a Function
keywords: profiling

  The linetimes.stp script takes two arguments: where to find the
  function and the function name. linetimes.stp will instrument each
  line in the function. It will print out the number of times that the
  function is called, a table with the average and maximum time each
  line takes, and control flow information when the script exits.

  # stap linetimes.stp kernel sys_nanosleep -c "sleep 0.2"


profiling/periodic.stp - Show the Period of the Various Timers on the System
keywords: profiling

  The periodic.stp script uses the  kernel.trace("timer_expire_entry")
  tracepoint to collect data on period and frequency of the various
  timers on the system.  The script displays a sorted list of the
  timers observed on the system from most frequent to least frequent.
  The script needs to be compiled with the '--all-modules' option to
  produce list the function names.  Optionally, this script can be used
  with a numerical argument to indicate the interval in seconds between
  printing output.

  # stap periodic.stp --all-modules -c "sleep 0.2"


profiling/pf2.stp - Profile Kernel Functions
keywords: profiling

  The pf2.stp script sets up time-based sampling. Every five seconds it
  prints out a sorted list with the top ten kernel functions with
  samples.

  # stap pf2.stp -c "sleep 0.2"


profiling/pf3.stp - Profile Kernel Functions
keywords: profiling

  The pf3.stp script sets up time-based sampling. Every five seconds it
  prints out a sorted list with the top twenty kernel and/or user
  functions with samples.  Use any of --ldd, --all-modules, -d MODULE,
  -d /PATH/TO/EXEC to add more symbolic info.

  # stap pf3.stp -c "sleep 6" --all-modules --ldd


profiling/sched_switch.stp - Display the Task Switches Happening in the Scheduler
keywords: profiling function

  The sched_switch.stp script takes two arguments, first argument can
  be "pid" or "name" to indicate what is being passed as second
  argument. The script will trace the process based on pid/name and
  print the scheduler switches happening with the process. If no
  arguments are passed, it displays all the scheduler switches. This
  can be used to understand which tasks schedule out the current
  process being traced, and when it gets scheduled in again.

  # stap  sched_switch.stp -c "sleep 1"


profiling/thread-times.stp - Profile Kernel Functions
keywords: profiling

  The thread-times.stp script sets up time-based sampling.  Every five
  seconds it prints out a sorted list with the top twenty threads
  occupying the CPUs, broken down as a percentage of user and kernel
  time.

  # stap thread-times.stp -c "sleep 0.2"


profiling/timeout.stp - Show Processes Doing Polling Operations
keywords: profiling

  The timeout.stp script is based on a blog entry
  (http://udrepper.livejournal.com/19041.html) mentioning a need for a
  tool to help developers find applications that are polling. The
  timeout.stp script monitors systemcall used for polling and records
  the systemcalls that timed out rather than returned because some
  action occurred. The script updates the screen once a second with the
  top twenty processes.

  # stap timeout.stp -c "sleep 0.2"


profiling/topsys.stp - Show Processes Doing Polling Operations
keywords: profiling

   The topsys.stp script lists out the top twenty systemcalls for the
  previous 5 seconds. The output is sorted from most frequent to least
  frequent.

  # stap topsys.stp -c "sleep 0.2"


virtualization/kvm_service_time.stp - Time Statistics on KVM Exit Reasons
keywords: virtualization kvm

  The kvm_service_time.stp script tracks the statistics about the
  amount of time that the processor left the guest virtual machine for
  each exit reason (for example fixing up a page table or handling an
  IO operation).  When the script exits it prints out the number of
  times each exit reason was encountered, the total duration of time it
  left the guest VM, the minimum time, the average time, and the
  maximum time in microseconds for that exit reason. On Linux 2.6.38
  and newer kernel the script can automatically determine whether it is
  running on Intel or AMD processors. For older kernels with a
  kernel.trace("kvm_exit") tracepoint that does not have the $isa
  parameter you can explicitly state the kvm type with a "-G kvm=intel"
  or "-G kvm=amd" on the command line.

  # stap kvm_service_time.stp -c "sleep 0.2"


virtualization/qemu_count.stp - Tally the Number of User-Space QEMU Events
keywords: virtualization qemu kvm

  The qemu_count.stp script tallies the number of times each of the
  user-space qemu probepoints is encountered. When the script exits, it
  prints a list of the number of times each user-space qemu probepoint
  is encountered.

  # stap qemu_count.stp -c "sleep 0.2"


virtualization/qemu_io.stp - Tally the Number of User-Space QEMU IO on Each IO Port
keywords: virtualization qemu kvm io

  The qemu_io.stp script tallies the number of times each of the IO
  port on the guest virtual machines is touched by a input or output
  operation. When the script exits, it prints a count of the number of
  times each IO port read and written.

  # stap qemu_io.stp -c "sleep 0.2"