History log of /linux-master/tools/perf/Documentation/perf.txt
Revision Date Author Comments
# 0bdfbd04 08-Feb-2024 Adrian Hunter <adrian.hunter@intel.com>

perf tools: Make it possible to see perf's kernel and module memory mappings

Dump kmaps if using 'perf --debug kmaps' or verbose > 2 (e.g. -vvv) for
tools 'perf script' and 'perf report' if there is no browser.

Example:

$ perf --debug kmaps script 2>&1 >/dev/null | grep kvm.intel
build id event received for /lib/modules/6.7.2-local/kernel/arch/x86/kvm/kvm-intel.ko: 0691d75e10e72ebbbd45a44c59f6d00a5604badf [20]
Map: 0-3a3 4f5d8 [kvm_intel].modinfo
Map: 0-5240 5f280 [kvm_intel]__versions
Map: 0-30 64 [kvm_intel].note.Linux
Map: 0-14 644c0 [kvm_intel].orc_header
Map: 0-5297 43680 [kvm_intel].rodata
Map: 0-5bee 3b837 [kvm_intel].text.unlikely
Map: 0-7e0 41430 [kvm_intel].noinstr.text
Map: 0-2080 713c0 [kvm_intel].bss
Map: 0-26 705c8 [kvm_intel].data..read_mostly
Map: 0-5888 6a4c0 [kvm_intel].data
Map: 0-22 70220 [kvm_intel].data.once
Map: 0-40 705f0 [kvm_intel].data..percpu
Map: 0-1685 41d20 [kvm_intel].init.text
Map: 0-4b8 6fd60 [kvm_intel].init.data
Map: 0-380 70248 [kvm_intel]__dyndbg
Map: 0-8 70218 [kvm_intel].exit.data
Map: 0-438 4f980 [kvm_intel]__param
Map: 0-5f5 4ca0f [kvm_intel].rodata.str1.1
Map: 0-3657 493b8 [kvm_intel].rodata.str1.8
Map: 0-e0 70640 [kvm_intel].data..ro_after_init
Map: 0-500 70ec0 [kvm_intel].gnu.linkonce.this_module
Map: ffffffffc13a7000-ffffffffc1421000 a0 /lib/modules/6.7.2-local/kernel/arch/x86/kvm/kvm-intel.ko

The example above shows how the module section mappings are all wrong
except for the main .text mapping at 0xffffffffc13a7000.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Like Xu <like.xu.linux@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240208085326.13432-2-adrian.hunter@intel.com


# 72108c0b 31-Oct-2023 Yang Jihong <yangjihong1@huawei.com>

perf tools: Add --debug-file option to redirect debug output

Currently, debug messages is output to stderr, add --debug-file option to
support redirection to a specified file.

Some test scenarios:

# perf --list-opts
--help --version --exec-path --html-path --paginate --no-pager --debugfs-dir --buildid-dir --list-cmds --list-opts --debug --debug-file

# perf --debug-file
No path given for --debug-file.

Usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]

# perf --debug-file /sys/perf.log record -v true
Open debug file '/sys/perf.log' failed: Permission denied

Usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]

# perf --debug-file /tmp/perf.log record -v true
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.013 MB perf.data (26 samples) ]
# cat /tmp/perf.log
DEBUGINFOD_URLS=
Using CPUID GenuineIntel-6-3E-4
nr_cblocks: 0
affinity: SYS
mmap flush: 1
comp level: 0
mmap size 528384B
Control descriptor is not initialized
mmap size 528384B
Looking at the vmlinux_path (8 entries long)
Using /proc/kcore for kernel data
Using /proc/kallsyms for symbols
symbol:unmap_start file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:unmap_complete file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:map_start file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:map_complete file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:reloc_start file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:reloc_complete file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:init_start file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:init_complete file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:lll_lock_wait_private file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:lll_lock_wait file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:setjmp file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:longjmp file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:longjmp_target file:(null) line:0 offset:0 return:0 lazy:(null)
failed to write feature HYBRID_TOPOLOGY

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231031105523.1472558-1-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 2adacd7f 13-Apr-2022 James Clark <james.clark@arm.com>

perf docs: Add man page entry for Arm SPE

The SPE integration in Perf has quite a few usability quirks that
can't be found by just reading the reference manual. So document this
and at the same time add a summary of the feature that is also hard to
find elsewhere.

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
Co-authored-by: Al Grant <al.grant@arm.com>
Co-authored-by: Luke Dare <Luke.Dare@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220413084021.2556142-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 0ff26efe 04-Apr-2022 Michael Petlan <mpetlan@redhat.com>

perf docs: Add perf-iostat link to manpages

Signed-off-by: Michael Petlan <mpetlan@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220404221541.30312-1-mpetlan@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 9bb8b74b 19-Nov-2020 Ian Rogers <irogers@google.com>

perf docs: Add man pages to see also

Add all other man pages to the "see also" list except for
perf-script-perl and perf-script-python that are linked to from
perf-script.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20201120063037.3166069-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 99f63817 09-Sep-2020 Zejiang Tang <tangzejiang@loongson.cn>

perf docs: Improve help information in perf.txt

perf has many undocumented options, such as:-vv, --exec-path,
--html-path, -p, --paginate,--no-pager, --debugfs-dir, --buildid-dir,
--list-cmds, --list-opts.

Add entris for these options in perf.txt.

Signed-off-by: Zejiang Tang <tangzejiang@loongson.cn>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Link: http://lore.kernel.org/lkml/1599645194-8438-1-git-send-email-tangzejiang@loongson.cn
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# ccd26741 08-Nov-2019 Ravi Bangoria <ravi.bangoria@linux.ibm.com>

perf tool: Provide an option to print perf_event_open args and return value

Perf record with verbose=2 already prints this information along with
whole lot of other traces which requires lot of scrolling. Introduce
an option to print only perf_event_open() arguments and return value.

Sample o/p:

$ perf --debug perf-event-open=1 record -- ls > /dev/null
------------------------------------------------------------
perf_event_attr:
size 112
{ sample_period, sample_freq } 4000
sample_type IP|TID|TIME|PERIOD
read_format ID
disabled 1
inherit 1
exclude_kernel 1
mmap 1
comm 1
freq 1
enable_on_exec 1
task 1
precise_ip 3
sample_id_all 1
exclude_guest 1
mmap2 1
comm_exec 1
ksymbol 1
bpf_event 1
------------------------------------------------------------
sys_perf_event_open: pid 4308 cpu 0 group_fd -1 flags 0x8 = 4
sys_perf_event_open: pid 4308 cpu 1 group_fd -1 flags 0x8 = 5
sys_perf_event_open: pid 4308 cpu 2 group_fd -1 flags 0x8 = 6
sys_perf_event_open: pid 4308 cpu 3 group_fd -1 flags 0x8 = 8
sys_perf_event_open: pid 4308 cpu 4 group_fd -1 flags 0x8 = 9
sys_perf_event_open: pid 4308 cpu 5 group_fd -1 flags 0x8 = 10
sys_perf_event_open: pid 4308 cpu 6 group_fd -1 flags 0x8 = 11
sys_perf_event_open: pid 4308 cpu 7 group_fd -1 flags 0x8 = 12
------------------------------------------------------------
perf_event_attr:
type 1
size 112
config 0x9
watermark 1
sample_id_all 1
bpf_event 1
{ wakeup_events, wakeup_watermark } 1
------------------------------------------------------------
sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8
sys_perf_event_open failed, error -13
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.002 MB perf.data (9 samples) ]

Committer notes:

Just like the 'verbose' variable this new 'debug_peo_args' needs to be
added to util/python.c, since we don't link the debug.o file in the
python binding, which ended up making 'perf test python' fail with:

# perf test -v python
18: 'import perf' in python :
--- start ---
test child forked, pid 19237
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: /tmp/build/perf/python/perf.so: undefined symbol: debug_peo_args
test child finished with -1
---- end ----
'import perf' in python: FAILED!
#

After adding that new variable to util/python.c:

# perf test -v python
18: 'import perf' in python :
--- start ---
test child forked, pid 22364
test child finished with 0
---- end ----
'import perf' in python: Ok
#

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20191108094128.28769-1-ravi.bangoria@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 6cf62656 13-May-2019 Thomas Richter <tmricht@linux.ibm.com>

perf docs: Add description for stderr

'perf report' displays recorded data on the screen and emits warnings
and debug messages in the status line (last one on screen).

perf also supports the possibility to write all debug messages to stderr
(instead of writing them to the status line).

This is achieved with the following command:

# ./perf --debug stderr=1 report -vvvvv -i ~/fast.data 2>/tmp/2
# ll /tmp/2
-rw-rw-r-- 1 tmricht tmricht 5420835 May 7 13:46 /tmp/2
#

The usage of variable stderr=1 is not documented, so add it to the perf
man page.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20190513080220.91966-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# a1853e2c 05-Oct-2015 Jiri Olsa <jolsa@kernel.org>

perf tools: Handle -h and -v options

Adding handling for '-h' and '-v' options to invoke help and version
command respectively.

Current behaviour is:

$ perf -v
Unknown option: -v

Usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]
$ perf -h
Unknown option: -h

Usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]

New behaviour:

$ perf -h

usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]

The most commonly used perf commands are:
annotate Read perf.data (created by perf record) and display annotated code
archive Create archive with object files with build-ids found in perf.data file
bench General framework for benchmark suites
...

$ perf -v
perf version 4.3.rc3.gc99e32

Updated man page.

Requested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1444068369-20978-10-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# edbe9817 20-Feb-2015 Jiri Olsa <jolsa@kernel.org>

perf data: Add perf data to CTF conversion support

Adding 'perf data convert' to convert perf data file into different
format. This patch adds support for CTF format conversion.

To convert perf.data into CTF run:
$ perf data convert --to-ctf=./ctf-data/
[ perf data convert: Converted 'perf.data' into CTF data './ctf-data/' ]
[ perf data convert: Converted and wrote 11.268 MB (100230 samples) ]

The command will create CTF metadata out of perf.data file (or one
specified via -i option) and then convert all sample events into single
CTF stream.

Each sample_type bit is translated into separated CTF event field apart
from following exceptions:

PERF_SAMPLE_RAW - added in next patch
PERF_SAMPLE_READ - TODO
PERF_SAMPLE_CALLCHAIN - TODO
PERF_SAMPLE_BRANCH_STACK - TODO
PERF_SAMPLE_REGS_USER - TODO
PERF_SAMPLE_STACK_USER - TODO

$ perf --debug=data-convert=2 data convert ...

The converted CTF data could be analyzed by CTF tools, like babletrace
or tracecompass [1].

$ babeltrace ./ctf-data/
[03:19:13.962125533] (+?.?????????) cycles: { }, { ip = 0xFFFFFFFF8105443A, tid = 20714, pid = 20714, period = 1 }
[03:19:13.962130001] (+0.000004468) cycles: { }, { ip = 0xFFFFFFFF8105443A, tid = 20714, pid = 20714, period = 1 }
[03:19:13.962131936] (+0.000001935) cycles: { }, { ip = 0xFFFFFFFF8105443A, tid = 20714, pid = 20714, period = 8 }
[03:19:13.962133732] (+0.000001796) cycles: { }, { ip = 0xFFFFFFFF8105443A, tid = 20714, pid = 20714, period = 114 }
[03:19:13.962135557] (+0.000001825) cycles: { }, { ip = 0xFFFFFFFF8105443A, tid = 20714, pid = 20714, period = 2087 }
[03:19:13.962137627] (+0.000002070) cycles: { }, { ip = 0xFFFFFFFF81361938, tid = 20714, pid = 20714, period = 37582 }
[03:19:13.962161091] (+0.000023464) cycles: { }, { ip = 0xFFFFFFFF8124218F, tid = 20714, pid = 20714, period = 600246 }
[03:19:13.962517569] (+0.000356478) cycles: { }, { ip = 0xFFFFFFFF811A75DB, tid = 20714, pid = 20714, period = 1325731 }
[03:19:13.969518008] (+0.007000439) cycles: { }, { ip = 0x34080917B2, tid = 20714, pid = 20714, period = 1144298 }

The following members to the ctf-environment were decided to be added to
distinguish and specify perf CTF data:

- domain

It says "kernel" because it contains a kernel trace (not to be
confused with a user space like lttng-ust does)

- tracer_name

It says perf. This can be used to distinguish between lttng and perf
CTF based trace.

- version

The kernel version from stream. In addition to release, this is what
it looks like on a Debian kernel:

release = "3.14-1-amd64";
version = "3.14.0";

[1] http://projects.eclipse.org/projects/tools.tracecompass

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1424470628-5969-4-git-send-email-jolsa@kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 99ce8e9f 01-Dec-2014 Jiri Olsa <jolsa@kernel.org>

perf tools: Add --buildid-dir option to set cache directory

Adding --buildid-dir to be able to set specific cache directory. It's
going to be handy for buildid tests coming in shortly.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1417460789-13874-4-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# bbb2cea7 16-Jul-2014 Jiri Olsa <jolsa@redhat.com>

perf tools: Add --debug optionto set debug variable

Adding --debug option as a way to setup debug variables. Starting with
support for verbose, more will come.

It's possible to use it now with report command:
$ perf --debug verbose ...
$ perf --debug verbose=2 ...

I'll need this support to add separated debug variable for ordered
events change in order to separate debug output out of standard verbose
stream.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140717105500.GG516@krava.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>


# 0895cf0a 13-Jan-2010 Kirill Smelkov <kirr@landau.phys.spbu.ru>

perf: Fix few typos + cosmetics

Signed-off-by: Kirill Smelkov <kirr@landau.phys.spbu.ru>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1263396139-4798-2-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


# 86470930 06-Jun-2009 Ingo Molnar <mingo@elte.hu>

perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/

Several people have suggested that 'perf' has become a full-fledged
tool that should be moved out of Documentation/. Move it to the
(new) tools/ directory.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>