SYSTEMTAP EXAMPLES INDEX BY KEYWORD
(see also index.txt)
= AUDIT =
process/auditbt.stp - Generate backtraces for kernel audit events
keywords: monitoring security audit backtrace
Attaches to the kernel audit-log paths (also used by libaudit), and
log every record being sent, along with a user-space backtrace of the
process that caused it.
# stap auditbt.stp -d /usr/bin/sudo --ldd -c "sudo true"
= AUTOFS =
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"
= BACKTRACE =
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/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/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"
process/auditbt.stp - Generate backtraces for kernel audit events
keywords: monitoring security audit backtrace
Attaches to the kernel audit-log paths (also used by libaudit), and
log every record being sent, along with a user-space backtrace of the
process that caused it.
# stap auditbt.stp -d /usr/bin/sudo --ldd -c "sudo true"
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/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"
= CALLGRAPH =
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"
= CPU =
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"
= DEVICE =
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"
= DISK =
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"
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 (in sectors) 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/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`"
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"
= DROP =
network/netfilter_drop.stp - System-Wide Network Packet Dropping Tool
keywords: network drop packets
The script drops the specified number of packets of the specified
protocol. Valid protocols are TCP, UDP, or ALL. If ALL is specified,
all incoming packets are dropped. The number of packets to drop can
be specified with a positive integer. A value of 0 indicates that
packets should be dropped until the user manually exits.
# stap -g netfilter_drop.stp TCP 1 -c "sleep 2"
= FILE =
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"
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 $$
= FILESYSTEM =
general/badname.stp - Bad Filename Filter
keywords: filesystem
The badname.stp script shows how one could prevent the creation of
files with undesirable names using guru mode.
# stap -g badname.stp -c "touch /tmp/myXXXbadnameXXXfile.$$ 2>&1 | grep \
denied"
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"
= FORMAT =
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
= FUNCTION =
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"
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/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"
= FUTEX =
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"
= INTERRUPT =
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"
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"
= IO =
general/alias_suffixes.stp - Count I/O Syscalls using Alias Suffixes
keywords: io statistics
alias_suffixes.stp is a demonstration of how alias suffixes in the
systemtap language might be used. The script tracks the wall clock
time for each invocation of the system calls open, close, read, and
write. When the script exists it prints out the minimum, average, and
maximum times in microseconds for each system call, followed by a
count of times that each syscall was invoked and a histogram showing
the distributions of times.
# stap alias_suffixes.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"
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"
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"
= KVM =
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"
= LIMITS =
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"
= LOCKING =
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"
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/mutex-contention.stp - pthread mutex contention analysis
keywords: locking
Tracks pthread-mutex initialization/use and underlying futex
operations, to identify (with backtraces/symbol-names) the mutexes
suffering most contention. Invoke with "NNN -d SHLIB --ldd"
# stap mutex-contention.stp 100 -c "sleep 0.2"
= MEMORY =
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>'
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"
= MONITORING =
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"
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/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"
process/auditbt.stp - Generate backtraces for kernel audit events
keywords: monitoring security audit backtrace
Attaches to the kernel audit-log paths (also used by libaudit), and
log every record being sent, along with a user-space backtrace of the
process that caused it.
# stap auditbt.stp -d /usr/bin/sudo --ldd -c "sudo true"
= NANOSLEEP =
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"
= NETWORK =
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/netfilter_drop.stp - System-Wide Network Packet Dropping Tool
keywords: network drop packets
The script drops the specified number of packets of the specified
protocol. Valid protocols are TCP, UDP, or ALL. If ALL is specified,
all incoming packets are dropped. The number of packets to drop can
be specified with a positive integer. A value of 0 indicates that
packets should be dropped until the user manually exits.
# stap -g netfilter_drop.stp TCP 1 -c "sleep 2"
network/netfilter_summary.stp - System-Wide Count of Network Packets by IPs
keywords: network traffic
The script watches all IPv4 network traffic on the system. On exit
the script prints a list showing the number of packets sent along
source IP address / destination IP address pair encountered, and the
total number of bytes sent among the pair. The list is ordered from
greatest to least number of packets seen among the source/destination
pairs.
# stap netfilter_summary.stp -c "sleep 0.4"
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/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
= NFS =
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/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/nfsdtop.stp - Keep track of NFS server statistics
keywords: nfs statistics
The nfsdtop.stp script gathers and displays NFS lookups,
# stap nfsd_unlink.stp -c "sleep 0.2"
= NUMA =
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"
= PACKETS =
network/netfilter_drop.stp - System-Wide Network Packet Dropping Tool
keywords: network drop packets
The script drops the specified number of packets of the specified
protocol. Valid protocols are TCP, UDP, or ALL. If ALL is specified,
all incoming packets are dropped. The number of packets to drop can
be specified with a positive integer. A value of 0 indicates that
packets should be dropped until the user manually exits.
# stap -g netfilter_drop.stp TCP 1 -c "sleep 2"
= PROCESS =
general/eventcount.stp - Count Specified Events
keywords: statistics thread process
The script periodically prints a count of specified events and their
related tid's over the course of execution. Numerous configuration
options exist to control filtering / reporting, see the script
source.
# stap eventcount.stp syscall.* -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"
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/ltrace.stp - uprobes-based ltrace
keywords: process
The ltrace.stp script lists calls that the designated process makes
through PLTs (procedure linkage tables), generally into shared
libraries.
# stap ltrace.stp -c ls || echo PR14738
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/psig.stp - Print Process File Descriptors
keywords: process signal
Run psig.stp to produce a human-readable summary of the signal
handling configuration of a given process. Specify the process-id as
-x PID for fastest performance.
# stap -DMAXACTION=10000 -g psig.stp -x $$
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/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 =
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/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"
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/perf.stp - Show performance ratios using perf.counter to access performance counters
keywords: profiling
On exit the perf.stp script provides a sorted list showing cycles per
insn, branches per insn, and cache refs per insn
# stap perf.stp -c "find /usr/bin -name \"l*\" -printf \"%h/%f %s %Cx \
%Ck%CM %Y\n\""
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/User 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"
= QEMU =
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"
= REGEX =
general/regex.stp - Report opened files whose names match a given regex
keywords: regex
Uses the regex functionality to detect opened files whose names match
a pattern given on the command line. If no command line parameter is
given, demonstrate by filtering for files that end with an extension
showing them to be an archive.
# stap regex.stp -c "sleep 0.2"
= SCHEDULER =
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/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/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/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/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"
= SCSI =
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"
= SECURITY =
process/auditbt.stp - Generate backtraces for kernel audit events
keywords: monitoring security audit backtrace
Attaches to the kernel audit-log paths (also used by libaudit), and
log every record being sent, along with a user-space backtrace of the
process that caused it.
# stap auditbt.stp -d /usr/bin/sudo --ldd -c "sudo true"
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'
= SIGNAL =
process/psig.stp - Print Process File Descriptors
keywords: process signal
Run psig.stp to produce a human-readable summary of the signal
handling configuration of a given process. Specify the process-id as
-x PID for fastest performance.
# stap -DMAXACTION=10000 -g psig.stp -x $$
= SIGNALS =
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
= SIMPLE =
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
= SLAB =
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"
= SOCKET =
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/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"
= STAPGAMES =
stapgames/block.stp - block breaker game
keywords: stapgames
A block game where you progressively break the ceiling blocks until
clearing the level
# stap -p4 -Itapset/ block.stp
stapgames/eater.stp - eater game
keywords: stapgames
walk through a maze, eat stuff
# stap -p4 -Itapset/ eater.stp
stapgames/lifegame.stp - life game
keywords: stapgames
watch as your creation morphes into different forms
# stap -p4 -Itapset/ lifegame.stp
stapgames/pingpong.stp - pingpong game
keywords: stapgames
A simulated ball bounces around the terminal reflecting at the edges
# stap -p4 -Itapset/ pingpong.stp
= STATISTICS =
general/alias_suffixes.stp - Count I/O Syscalls using Alias Suffixes
keywords: io statistics
alias_suffixes.stp is a demonstration of how alias suffixes in the
systemtap language might be used. The script tracks the wall clock
time for each invocation of the system calls open, close, read, and
write. When the script exists it prints out the minimum, average, and
maximum times in microseconds for each system call, followed by a
count of times that each syscall was invoked and a histogram showing
the distributions of times.
# stap alias_suffixes.stp -c "sleep 0.2"
general/eventcount.stp - Count Specified Events
keywords: statistics thread process
The script periodically prints a count of specified events and their
related tid's over the course of execution. Numerous configuration
options exist to control filtering / reporting, see the script
source.
# 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/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>'
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/nfsdtop.stp - Keep track of NFS server statistics
keywords: nfs statistics
The nfsdtop.stp script gathers and displays NFS lookups,
# stap nfsd_unlink.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
= SYSCALL =
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"
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/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/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"
= TCP =
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/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"
= THREAD =
general/eventcount.stp - Count Specified Events
keywords: statistics thread process
The script periodically prints a count of specified events and their
related tid's over the course of execution. Numerous configuration
options exist to control filtering / reporting, see the script
source.
# stap eventcount.stp syscall.* -c 'sleep 0.2'
process/threadstacks.stp - Override default new-pthread stack sizes
keywords: thread
Overrides default NPTL pthread_create stack size for all new threads
created by target processes. Reports one line per process when the
related glibc variable __default_stacksize is updated. Moot for
glibc versions that support $LIBC_PTHREAD_DEFAULT_STACKSIZE_NP.
# stap -g threadstacks.stp -Gsize=65536 -c "sleep 1" -d stap
= TIME =
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"
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/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"
= TRACE =
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"
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
= TRACEPOINT =
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"
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/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"
= TRAFFIC =
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/netfilter_summary.stp - System-Wide Count of Network Packets by IPs
keywords: network traffic
The script watches all IPv4 network traffic on the system. On exit
the script prints a list showing the number of packets sent along
source IP address / destination IP address pair encountered, and the
total number of bytes sent among the pair. The list is ordered from
greatest to least number of packets seen among the source/destination
pairs.
# stap netfilter_summary.stp -c "sleep 0.4"
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/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"
= TTY =
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"
= UTILIZATION =
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"
= VIRTUALIZATION =
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 $isa
parameter you can explicitly state the kvm type with a "-G kvm=intel"
or "-G kvm=amd" on the command line.
# stap kvm_service_time.stp -c "sleep 0.2"
virtualization/qemu_count.stp - Tally the Number of User-Space QEMU Events
keywords: virtualization qemu kvm
The qemu_count.stp script tallies the number of times each of the
user-space qemu probepoints is encountered. When the script exits, it
prints a list of the number of times each user-space qemu probepoint
is encountered.
# stap qemu_count.stp -c "sleep 0.2"
virtualization/qemu_io.stp - Tally the Number of User-Space QEMU IO on Each IO Port
keywords: virtualization qemu kvm io
The qemu_io.stp script tallies the number of times each of the IO
port on the guest virtual machines is touched by a input or output
operation. When the script exits, it prints a count of the number of
times each IO port read and written.
# stap qemu_io.stp -c "sleep 0.2"
= WATCHDOG =
general/watchdog.stp - Watchdog Timer for Arbitrary Events
keywords: watchdog backtrace
The watchdog.stp script provides a watchdog timer mechanism for
arbitrary events. The script takes three arguments: the events to
start watchdog timer, the event to stop the watchdog timer, and the
time in millseconds for the watchdog. If the watchdog timer is
exceed, the script will trigger a stack backtrace of the user-process
that timed out using pstack. This script can be used to diagnose what
the userspace application is doing when a slower than expected
operation occurs.
# stap watchdog.stp 'syscall.nanosleep' 'syscall.nanosleep.return' 1000 \
-c "sleep 0.2"
= WATCHPOINT =
memory/hw_watch_addr.stp - Watch a Kernel Address Using Breakpoint Hardware
keywords: memory watchpoint
The script will watch accesses to a single kernel address and prints
a traceback each time the address is accessed. This script needs to
be run as root to allow access to the breakpoint hardware.
# stap --all-modules hw_watch_addr.stp 0x`grep "pid_max$" /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"
