-a, --all-cpus
System-wide collection from all CPUs.
-e, --expr, --event
List of syscalls and other perf events (tracepoints, HW cache
events, etc) to show. Globbing is supported, e.g.: "epoll_*",
"msg", etc. See perf list for a complete list of events.
Prefixing with ! shows all syscalls but the ones specified.
You may need to escape it.
--filter=<filter>
Event filter. This option should follow an event selector
(-e) which selects tracepoint event(s).
-D msecs, --delay msecs
After starting the program, wait msecs before measuring. This
is useful to filter out the startup phase of the program,
which is often very different.
-o, --output=
Output file name.
-p, --pid=
Record events on existing process ID (comma separated list).
-t, --tid=
Record events on existing thread ID (comma separated list).
-u, --uid=
Record events in threads owned by uid. Name or number.
-G, --cgroup
Record events in threads in a cgroup.
Look for cgroups to set at the /sys/fs/cgroup/perf_event directory, then
remove the /sys/fs/cgroup/perf_event/ part and try:
perf trace -G A -e sched:*switch
Will set all raw_syscalls:sys_{enter,exit}, pgfault, vfs_getname, etc
_and_ sched:sched_switch to the 'A' cgroup, while:
perf trace -e sched:*switch -G A
will only set the sched:sched_switch event to the 'A' cgroup, all the
other events (raw_syscalls:sys_{enter,exit}, etc are left "without"
a cgroup (on the root cgroup, sys wide, etc).
Multiple cgroups:
perf trace -G A -e sched:*switch -G B
the syscall ones go to the 'A' cgroup, the sched:sched_switch goes
to the 'B' cgroup.
--filter-pids=
Filter out events for these pids and for trace itself (comma
separated list).
-v, --verbose
Increase the verbosity level.
--no-inherit
Child tasks do not inherit counters.
-m, --mmap-pages=
Number of mmap data pages (must be a power of two) or size
specification with appended unit character - B/K/M/G. The
size is rounded up to have nearest pages power of two value.
-C, --cpu
Collect samples only on the list of CPUs provided. Multiple
CPUs can be provided as a comma-separated list with no space:
0,1. Ranges of CPUs are specified with -: 0-2. In per-thread
mode with inheritance mode on (default), Events are captured
only when the thread executes on the designated CPUs. Default
is to monitor all CPUs.
--duration
Show only events that had a duration greater than N.M ms.
--sched
Accrue thread runtime and provide a summary at the end of the
session.
--failure
Show only syscalls that failed, i.e. that returned < 0.
-i, --input
Process events from a given perf data file.
-T, --time
Print full timestamp rather time relative to first sample.
--comm
Show process COMM right beside its ID, on by default, disable
with --no-comm.
-s, --summary
Show only a summary of syscalls by thread with min, max, and
average times (in msec) and relative stddev.
-S, --with-summary
Show all syscalls followed by a summary by thread with min,
max, and average times (in msec) and relative stddev.
--errno-summary
To be used with -s or -S, to show stats for the errnos
experienced by syscalls, using only this option will trigger
--summary.
--tool_stats
Show tool stats such as number of times fd→pathname was
discovered thru hooking the open syscall return + vfs_getname
or via reading /proc/pid/fd, etc.
-f, --force
Don't complain, do it.
-F=[all|min|maj], --pf=[all|min|maj]
Trace pagefaults. Optionally, you can specify whether you
want minor, major or all pagefaults. Default value is maj.
--syscalls
Trace system calls. This options is enabled by default,
disable with --no-syscalls.
--call-graph [mode,type,min[,limit],order[,key][,branch]]
Setup and enable call-graph (stack chain/backtrace)
recording. See --call-graph section in perf-record and
perf-report man pages for details. The ones that are most
useful in perf trace are dwarf and lbr, where available, try:
perf trace --call-graph dwarf.
Using this will, for the root user, bump the value of --mmap-pages to 4
times the maximum for non-root users, based on the kernel.perf_event_mlock_kb
sysctl. This is done only if the user doesn't specify a --mmap-pages value.
--kernel-syscall-graph
Show the kernel callchains on the syscall exit path.
--max-events=N
Stop after processing N events. Note that strace-like events
are considered only at exit time or when a syscall is
interrupted, i.e. in those cases this option is equivalent to
the number of lines printed.
--switch-on EVENT_NAME
Only consider events after this event is found.
--switch-off EVENT_NAME
Stop considering events after this event is found.
--show-on-off-events
Show the --switch-on/off events too.
--max-stack
Set the stack depth limit when parsing the callchain,
anything beyond the specified depth will be ignored. Note
that at this point this is just about the presentation part,
i.e. the kernel is still not limiting, the overhead of
callchains needs to be set via the knobs in --call-graph
dwarf.
Implies '--call-graph dwarf' when --call-graph not present on the
command line, on systems where DWARF unwinding was built in.
Default: /proc/sys/kernel/perf_event_max_stack when present for
live sessions (without --input/-i), 127 otherwise.
--min-stack
Set the stack depth limit when parsing the callchain,
anything below the specified depth will be ignored. Disabled
by default.
Implies '--call-graph dwarf' when --call-graph not present on the
command line, on systems where DWARF unwinding was built in.
--print-sample
Print the PERF_RECORD_SAMPLE PERF_SAMPLE_ info for the
raw_syscalls:sys_{enter,exit} tracepoints, for debugging.
--proc-map-timeout
When processing pre-existing threads /proc/XXX/mmap, it may
take a long time, because the file may be huge. A time out is
needed in such cases. This option sets the time out limit.
The default value is 500 ms.
--sort-events
Do sorting on batches of events, use when noticing out of
order events that may happen, for instance, when a thread
gets migrated to a different CPU while processing a syscall.
--libtraceevent_print
Use libtraceevent to print tracepoint arguments. By default
perf trace uses the same beautifiers used in the strace-like
enter+exit lines to augment the tracepoint arguments.
--map-dump
Dump BPF maps setup by events passed via -e, for instance the
augmented_raw_syscalls living in
tools/perf/examples/bpf/augmented_raw_syscalls.c. For now
this dumps just boolean map values and integer keys, in time
this will print in hex by default and use BTF when available,
as well as use functions to do pretty printing using the
existing perf trace syscall arg beautifiers to map integer
arguments to strings (pid to comm, syscall id to syscall
name, etc).
