Commit 81de3bf3 authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo

libperf: Add man pages

Change the man page generation to asciidoc, because it's easier to use
and has been more commonly used in related projects. Remove the current
rst pages.

Add 3 man pages to have a base for more additions:

  libperf.3          - overall description
  libperf-counting.7 - counting basics explained on simple example
  libperf-sampling.7 - sampling basics explained on simple example

The plan is to add more man pages to cover the basic API.

The build generates html and man pages:

  $ cd tools/lib/perf/Documentation
  $ make
    ASCIIDOC libperf.xml
    XMLTO    libperf.3
    ASCIIDOC libperf-counting.xml
    XMLTO    libperf-counting.7
    ASCIIDOC libperf-sampling.xml
    XMLTO    libperf-sampling.7
    ASCIIDOC libperf.html
    ASCIIDOC libperf-counting.html
    ASCIIDOC libperf-sampling.html

Add the following install targets:

   install-man      - man pages
   install-html     - html version of man pages
   install-examples - examples mentioned in the man pages
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191206210612.8676-3-jolsa@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 3ce311af
all: # SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
rst2man man/libperf.rst > man/libperf.7 # Most of this file is copied from tools/perf/Documentation/Makefile
rst2pdf tutorial/tutorial.rst
include ../../../scripts/Makefile.include
include ../../../scripts/utilities.mak
MAN3_TXT = libperf.txt
MAN7_TXT = libperf-counting.txt libperf-sampling.txt
MAN_EX = examples/*.c
MAN_TXT = $(MAN3_TXT) $(MAN7_TXT)
_MAN_XML = $(patsubst %.txt,%.xml,$(MAN_TXT))
_MAN_HTML = $(patsubst %.txt,%.html,$(MAN_TXT))
_MAN_3 = $(patsubst %.txt,%.3,$(MAN3_TXT))
_MAN_7 = $(patsubst %.txt,%.7,$(MAN7_TXT))
MAN_XML = $(addprefix $(OUTPUT),$(_MAN_XML))
MAN_HTML = $(addprefix $(OUTPUT),$(_MAN_HTML))
MAN_3 = $(addprefix $(OUTPUT),$(_MAN_3))
MAN_7 = $(addprefix $(OUTPUT),$(_MAN_7))
MAN_X = $(MAN_3) $(MAN_7)
# Make the path relative to DESTDIR, not prefix
ifndef DESTDIR
prefix ?=$(HOME)
endif
mandir ?= $(prefix)/share/man
man3dir = $(mandir)/man3
man7dir = $(mandir)/man7
docdir ?= $(prefix)/share/doc/libperf
htmldir = $(docdir)/html
exdir = $(docdir)/examples
ASCIIDOC = asciidoc
ASCIIDOC_EXTRA = --unsafe -f asciidoc.conf
ASCIIDOC_HTML = xhtml11
MANPAGE_XSL = manpage-normal.xsl
XMLTO_EXTRA =
XMLTO =xmlto
INSTALL ?= install
RM ?= rm -f
# For asciidoc ...
# -7.1.2, no extra settings are needed.
# 8.0-, set ASCIIDOC8.
#
# For docbook-xsl ...
# -1.68.1, set ASCIIDOC_NO_ROFF? (based on changelog from 1.73.0)
# 1.69.0, no extra settings are needed?
# 1.69.1-1.71.0, set DOCBOOK_SUPPRESS_SP?
# 1.71.1, no extra settings are needed?
# 1.72.0, set DOCBOOK_XSL_172.
# 1.73.0-, set ASCIIDOC_NO_ROFF
# If you had been using DOCBOOK_XSL_172 in an attempt to get rid
# of 'the ".ft C" problem' in your generated manpages, and you
# instead ended up with weird characters around callouts, try
# using ASCIIDOC_NO_ROFF instead (it works fine with ASCIIDOC8).
ifdef ASCIIDOC8
ASCIIDOC_EXTRA += -a asciidoc7compatible
endif
ifdef DOCBOOK_XSL_172
ASCIIDOC_EXTRA += -a libperf-asciidoc-no-roff
MANPAGE_XSL = manpage-1.72.xsl
else
ifdef ASCIIDOC_NO_ROFF
# docbook-xsl after 1.72 needs the regular XSL, but will not
# pass-thru raw roff codes from asciidoc.conf, so turn them off.
ASCIIDOC_EXTRA += -a libperf-asciidoc-no-roff
endif
endif
ifdef MAN_BOLD_LITERAL
XMLTO_EXTRA += -m manpage-bold-literal.xsl
endif
ifdef DOCBOOK_SUPPRESS_SP
XMLTO_EXTRA += -m manpage-suppress-sp.xsl
endif
DESTDIR ?=
DESTDIR_SQ = '$(subst ','\'',$(DESTDIR))'
export DESTDIR DESTDIR_SQ
# Please note that there is a minor bug in asciidoc.
# The version after 6.0.3 _will_ include the patch found here:
# http://marc.theaimsgroup.com/?l=libtraceevent&m=111558757202243&w=2
#
# Until that version is released you may have to apply the patch
# yourself - yes, all 6 characters of it!
QUIET_SUBDIR0 = +$(MAKE) -C # space to separate -C and subdir
QUIET_SUBDIR1 =
ifneq ($(findstring $(MAKEFLAGS),w),w)
PRINT_DIR = --no-print-directory
else # "make -w"
NO_SUBDIR = :
endif
ifneq ($(findstring $(MAKEFLAGS),s),s)
ifneq ($(V),1)
QUIET_ASCIIDOC = @echo ' ASCIIDOC '$@;
QUIET_XMLTO = @echo ' XMLTO '$@;
endif
endif
all: $(MAN_X) $(MAN_HTML)
$(MAN_HTML) $(MAN_X): asciidoc.conf
install-man: all
$(call QUIET_INSTALL, man) \
$(INSTALL) -d -m 755 $(DESTDIR)$(man3dir); \
$(INSTALL) -m 644 $(MAN_3) $(DESTDIR)$(man3dir); \
$(INSTALL) -d -m 755 $(DESTDIR)$(man7dir); \
$(INSTALL) -m 644 $(MAN_7) $(DESTDIR)$(man7dir);
install-html:
$(call QUIET_INSTALL, html) \
$(INSTALL) -d -m 755 $(DESTDIR)$(htmldir); \
$(INSTALL) -m 644 $(MAN_HTML) $(DESTDIR)$(htmldir); \
install-examples:
$(call QUIET_INSTALL, examples) \
$(INSTALL) -d -m 755 $(DESTDIR)$(exdir); \
$(INSTALL) -m 644 $(MAN_EX) $(DESTDIR)$(exdir); \
CLEAN_FILES = \
$(MAN_XML) $(addsuffix +,$(MAN_XML)) \
$(MAN_HTML) $(addsuffix +,$(MAN_HTML)) \
$(MAN_X)
clean: clean:
rm -f man/libperf.7 $(call QUIET_CLEAN, Documentation) $(RM) $(CLEAN_FILES)
rm -f tutorial/tutorial.pdf
$(MAN_3): $(OUTPUT)%.3: %.xml
$(QUIET_XMLTO)$(XMLTO) -o $(OUTPUT). -m $(MANPAGE_XSL) $(XMLTO_EXTRA) man $<
$(MAN_7): $(OUTPUT)%.7: %.xml
$(QUIET_XMLTO)$(XMLTO) -o $(OUTPUT). -m $(MANPAGE_XSL) $(XMLTO_EXTRA) man $<
$(MAN_XML): $(OUTPUT)%.xml: %.txt
$(QUIET_ASCIIDOC)$(ASCIIDOC) -b docbook -d manpage \
$(ASCIIDOC_EXTRA) -alibperf_version=$(EVENT_PARSE_VERSION) -o $@+ $< && \
mv $@+ $@
$(MAN_HTML): $(OUTPUT)%.html: %.txt
$(QUIET_ASCIIDOC)$(ASCIIDOC) -b $(ASCIIDOC_HTML) -d manpage \
$(ASCIIDOC_EXTRA) -aperf_version=$(EVENT_PARSE_VERSION) -o $@+ $< && \
mv $@+ $@
## linktep: macro
#
# Usage: linktep:command[manpage-section]
#
# Note, {0} is the manpage section, while {target} is the command.
#
# Show TEP link as: <command>(<section>); if section is defined, else just show
# the command.
[macros]
(?su)[\\]?(?P<name>linktep):(?P<target>\S*?)\[(?P<attrlist>.*?)\]=
[attributes]
asterisk=&#42;
plus=&#43;
caret=&#94;
startsb=&#91;
endsb=&#93;
tilde=&#126;
ifdef::backend-docbook[]
[linktep-inlinemacro]
{0%{target}}
{0#<citerefentry>}
{0#<refentrytitle>{target}</refentrytitle><manvolnum>{0}</manvolnum>}
{0#</citerefentry>}
endif::backend-docbook[]
ifdef::backend-docbook[]
ifndef::tep-asciidoc-no-roff[]
# "unbreak" docbook-xsl v1.68 for manpages. v1.69 works with or without this.
# v1.72 breaks with this because it replaces dots not in roff requests.
[listingblock]
<example><title>{title}</title>
<literallayout>
ifdef::doctype-manpage[]
&#10;.ft C&#10;
endif::doctype-manpage[]
|
ifdef::doctype-manpage[]
&#10;.ft&#10;
endif::doctype-manpage[]
</literallayout>
{title#}</example>
endif::tep-asciidoc-no-roff[]
ifdef::tep-asciidoc-no-roff[]
ifdef::doctype-manpage[]
# The following two small workarounds insert a simple paragraph after screen
[listingblock]
<example><title>{title}</title>
<literallayout>
|
</literallayout><simpara></simpara>
{title#}</example>
[verseblock]
<formalpara{id? id="{id}"}><title>{title}</title><para>
{title%}<literallayout{id? id="{id}"}>
{title#}<literallayout>
|
</literallayout>
{title#}</para></formalpara>
{title%}<simpara></simpara>
endif::doctype-manpage[]
endif::tep-asciidoc-no-roff[]
endif::backend-docbook[]
ifdef::doctype-manpage[]
ifdef::backend-docbook[]
[header]
template::[header-declarations]
<refentry>
<refmeta>
<refentrytitle>{mantitle}</refentrytitle>
<manvolnum>{manvolnum}</manvolnum>
<refmiscinfo class="source">libperf</refmiscinfo>
<refmiscinfo class="version">{libperf_version}</refmiscinfo>
<refmiscinfo class="manual">libperf Manual</refmiscinfo>
</refmeta>
<refnamediv>
<refname>{manname1}</refname>
<refname>{manname2}</refname>
<refname>{manname3}</refname>
<refname>{manname4}</refname>
<refname>{manname5}</refname>
<refname>{manname6}</refname>
<refname>{manname7}</refname>
<refname>{manname8}</refname>
<refname>{manname9}</refname>
<refname>{manname10}</refname>
<refname>{manname11}</refname>
<refname>{manname12}</refname>
<refname>{manname13}</refname>
<refname>{manname14}</refname>
<refname>{manname15}</refname>
<refname>{manname16}</refname>
<refname>{manname17}</refname>
<refname>{manname18}</refname>
<refname>{manname19}</refname>
<refname>{manname20}</refname>
<refname>{manname21}</refname>
<refname>{manname22}</refname>
<refname>{manname23}</refname>
<refname>{manname24}</refname>
<refname>{manname25}</refname>
<refname>{manname26}</refname>
<refname>{manname27}</refname>
<refname>{manname28}</refname>
<refname>{manname29}</refname>
<refname>{manname30}</refname>
<refpurpose>{manpurpose}</refpurpose>
</refnamediv>
endif::backend-docbook[]
endif::doctype-manpage[]
ifdef::backend-xhtml11[]
[linktep-inlinemacro]
<a href="{target}.html">{target}{0?({0})}</a>
endif::backend-xhtml11[]
#include <linux/perf_event.h>
#include <perf/evlist.h>
#include <perf/evsel.h>
#include <perf/cpumap.h>
#include <perf/threadmap.h>
#include <perf/mmap.h>
#include <perf/core.h>
#include <perf/event.h>
#include <stdio.h>
#include <unistd.h>
static int libperf_print(enum libperf_print_level level,
const char *fmt, va_list ap)
{
return vfprintf(stderr, fmt, ap);
}
union u64_swap {
__u64 val64;
__u32 val32[2];
};
int main(int argc, char **argv)
{
struct perf_evlist *evlist;
struct perf_evsel *evsel;
struct perf_mmap *map;
struct perf_cpu_map *cpus;
struct perf_event_attr attr = {
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
.disabled = 1,
.freq = 1,
.sample_freq = 10,
.sample_type = PERF_SAMPLE_IP|PERF_SAMPLE_TID|PERF_SAMPLE_CPU|PERF_SAMPLE_PERIOD,
};
int err = -1;
union perf_event *event;
libperf_init(libperf_print);
cpus = perf_cpu_map__new(NULL);
if (!cpus) {
fprintf(stderr, "failed to create cpus\n");
return -1;
}
evlist = perf_evlist__new();
if (!evlist) {
fprintf(stderr, "failed to create evlist\n");
goto out_cpus;
}
evsel = perf_evsel__new(&attr);
if (!evsel) {
fprintf(stderr, "failed to create cycles\n");
goto out_cpus;
}
perf_evlist__add(evlist, evsel);
perf_evlist__set_maps(evlist, cpus, NULL);
err = perf_evlist__open(evlist);
if (err) {
fprintf(stderr, "failed to open evlist\n");
goto out_evlist;
}
err = perf_evlist__mmap(evlist, 4);
if (err) {
fprintf(stderr, "failed to mmap evlist\n");
goto out_evlist;
}
perf_evlist__enable(evlist);
sleep(3);
perf_evlist__disable(evlist);
perf_evlist__for_each_mmap(evlist, map, false) {
if (perf_mmap__read_init(map) < 0)
continue;
while ((event = perf_mmap__read_event(map)) != NULL) {
int cpu, pid, tid;
__u64 ip, period, *array;
union u64_swap u;
array = event->sample.array;
ip = *array;
array++;
u.val64 = *array;
pid = u.val32[0];
tid = u.val32[1];
array++;
u.val64 = *array;
cpu = u.val32[0];
array++;
period = *array;
fprintf(stdout, "cpu %3d, pid %6d, tid %6d, ip %20llx, period %20llu\n",
cpu, pid, tid, ip, period);
perf_mmap__consume(map);
}
perf_mmap__read_done(map);
}
out_evlist:
perf_evlist__delete(evlist);
out_cpus:
perf_cpu_map__put(cpus);
return err;
}
libperf-counting(7)
===================
NAME
----
libperf-counting - counting interface
DESCRIPTION
-----------
The counting interface provides API to meassure and get count for specific perf events.
The following test tries to explain count on `counting.c` example.
It is by no means complete guide to counting, but shows libperf basic API for counting.
The `counting.c` comes with libbperf package and can be compiled and run like:
[source,bash]
--
$ gcc -o counting counting.c -lperf
$ sudo ./counting
count 176792, enabled 176944, run 176944
count 176242, enabled 176242, run 176242
--
It requires root access, because of the `PERF_COUNT_SW_CPU_CLOCK` event,
which is available only for root.
The `counting.c` example monitors two events on the current process and displays their count, in a nutshel it:
* creates events
* adds them to the event list
* opens and enables events through the event list
* does some workload
* disables events
* reads and displays event counts
* destroys the event list
The first thing you need to do before using libperf is to call init function:
[source,c]
--
8 static int libperf_print(enum libperf_print_level level,
9 const char *fmt, va_list ap)
10 {
11 return vfprintf(stderr, fmt, ap);
12 }
14 int main(int argc, char **argv)
15 {
...
35 libperf_init(libperf_print);
--
It will setup the library and sets function for debug output from library.
The `libperf_print` callback will receive any message with its debug level,
defined as:
[source,c]
--
enum libperf_print_level {
LIBPERF_ERR,
LIBPERF_WARN,
LIBPERF_INFO,
LIBPERF_DEBUG,
LIBPERF_DEBUG2,
LIBPERF_DEBUG3,
};
--
Once the setup is complete we start by defining specific events using the `struct perf_event_attr`.
We create software events for cpu and task:
[source,c]
--
20 struct perf_event_attr attr1 = {
21 .type = PERF_TYPE_SOFTWARE,
22 .config = PERF_COUNT_SW_CPU_CLOCK,
23 .read_format = PERF_FORMAT_TOTAL_TIME_ENABLED|PERF_FORMAT_TOTAL_TIME_RUNNING,
24 .disabled = 1,
25 };
26 struct perf_event_attr attr2 = {
27 .type = PERF_TYPE_SOFTWARE,
28 .config = PERF_COUNT_SW_TASK_CLOCK,
29 .read_format = PERF_FORMAT_TOTAL_TIME_ENABLED|PERF_FORMAT_TOTAL_TIME_RUNNING,
30 .disabled = 1,
31 };
--
The `read_format` setup tells perf to include timing details together with each count.
Next step is to prepare threads map.
In this case we will monitor current process, so we create threads map with single pid (0):
[source,c]
--
37 threads = perf_thread_map__new_dummy();
38 if (!threads) {
39 fprintf(stderr, "failed to create threads\n");
40 return -1;
41 }
42
43 perf_thread_map__set_pid(threads, 0, 0);
--
Now we create libperf's event list, which will serve as holder for the events we want:
[source,c]
--
45 evlist = perf_evlist__new();
46 if (!evlist) {
47 fprintf(stderr, "failed to create evlist\n");
48 goto out_threads;
49 }
--
We create libperf's events for the attributes we defined earlier and add them to the list:
[source,c]
--
51 evsel = perf_evsel__new(&attr1);
52 if (!evsel) {
53 fprintf(stderr, "failed to create evsel1\n");
54 goto out_evlist;
55 }
56
57 perf_evlist__add(evlist, evsel);
58
59 evsel = perf_evsel__new(&attr2);
60 if (!evsel) {
61 fprintf(stderr, "failed to create evsel2\n");
62 goto out_evlist;
63 }
64
65 perf_evlist__add(evlist, evsel);
--
Configure event list with the thread map and open events:
[source,c]
--
67 perf_evlist__set_maps(evlist, NULL, threads);
68
69 err = perf_evlist__open(evlist);
70 if (err) {
71 fprintf(stderr, "failed to open evsel\n");
72 goto out_evlist;
73 }
--
Both events are created as disabled (note the `disabled = 1` assignment above),
so we need to enable the whole list explicitely (both events).
From this moment events are counting and we can do our workload.
When we are done we disable the events list.
[source,c]
--
75 perf_evlist__enable(evlist);
76
77 while (count--);
78
79 perf_evlist__disable(evlist);
--
Now we need to get the counts from events, following code iterates throught the events list and read counts:
[source,c]
--
81 perf_evlist__for_each_evsel(evlist, evsel) {
82 perf_evsel__read(evsel, 0, 0, &counts);
83 fprintf(stdout, "count %llu, enabled %llu, run %llu\n",
84 counts.val, counts.ena, counts.run);
85 }
--
And finaly cleanup.
We close the whole events list (both events) and remove it together with the threads map:
[source,c]
--
87 perf_evlist__close(evlist);
88
89 out_evlist:
90 perf_evlist__delete(evlist);
91 out_threads:
92 perf_thread_map__put(threads);
93 return err;
94 }
--
REPORTING BUGS
--------------
Report bugs to <linux-perf-users@vger.kernel.org>.
LICENSE
-------
libperf is Free Software licensed under the GNU LGPL 2.1
RESOURCES
---------
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
SEE ALSO
--------
libperf(3), libperf-sampling(7)
libperf-sampling(7)
===================
NAME
----
libperf-sampling - sampling interface
DESCRIPTION
-----------
The sampling interface provides API to meassure and get count for specific perf events.
The following test tries to explain count on `sampling.c` example.
It is by no means complete guide to sampling, but shows libperf basic API for sampling.
The `sampling.c` comes with libbperf package and can be compiled and run like:
[source,bash]
--
$ gcc -o sampling sampling.c -lperf
$ sudo ./sampling
cpu 0, pid 0, tid 0, ip ffffffffad06c4e6, period 1
cpu 0, pid 4465, tid 4469, ip ffffffffad118748, period 18322959
cpu 0, pid 0, tid 0, ip ffffffffad115722, period 33544846
cpu 0, pid 4465, tid 4470, ip 7f84fe0cdad6, period 23687474
cpu 0, pid 0, tid 0, ip ffffffffad9e0349, period 34255790
cpu 0, pid 4465, tid 4469, ip ffffffffad136581, period 38664069
cpu 0, pid 0, tid 0, ip ffffffffad9e55e2, period 21922384
cpu 0, pid 4465, tid 4470, ip 7f84fe0ebebf, period 17655175
...
--
It requires root access, because it uses hardware cycles event.
The `sampling.c` example profiles/samples all CPUs with hardware cycles, in a nutshel it:
- creates events
- adds them to the event list
- opens and enables events through the event list
- sleeps for 3 seconds
- disables events
- reads and displays recorded samples
- destroys the event list
The first thing you need to do before using libperf is to call init function:
[source,c]
--
12 static int libperf_print(enum libperf_print_level level,
13 const char *fmt, va_list ap)
14 {
15 return vfprintf(stderr, fmt, ap);
16 }
23 int main(int argc, char **argv)
24 {
...
40 libperf_init(libperf_print);
--
It will setup the library and sets function for debug output from library.
The `libperf_print` callback will receive any message with its debug level,
defined as:
[source,c]
--
enum libperf_print_level {
LIBPERF_ERR,
LIBPERF_WARN,
LIBPERF_INFO,
LIBPERF_DEBUG,
LIBPERF_DEBUG2,
LIBPERF_DEBUG3,
};
--
Once the setup is complete we start by defining cycles event using the `struct perf_event_attr`:
[source,c]
--
29 struct perf_event_attr attr = {
30 .type = PERF_TYPE_HARDWARE,
31 .config = PERF_COUNT_HW_CPU_CYCLES,
32 .disabled = 1,
33 .freq = 1,
34 .sample_freq = 10,
35 .sample_type = PERF_SAMPLE_IP|PERF_SAMPLE_TID|PERF_SAMPLE_CPU|PERF_SAMPLE_PERIOD,
36 };
--
Next step is to prepare cpus map.
In this case we will monitor all the available CPUs:
[source,c]
--
42 cpus = perf_cpu_map__new(NULL);
43 if (!cpus) {
44 fprintf(stderr, "failed to create cpus\n");
45 return -1;
46 }
--
Now we create libperf's event list, which will serve as holder for the cycles event:
[source,c]
--
48 evlist = perf_evlist__new();
49 if (!evlist) {
50 fprintf(stderr, "failed to create evlist\n");
51 goto out_cpus;
52 }
--
We create libperf's event for the cycles attribute we defined earlier and add it to the list:
[source,c]
--
54 evsel = perf_evsel__new(&attr);
55 if (!evsel) {
56 fprintf(stderr, "failed to create cycles\n");
57 goto out_cpus;
58 }
59
60 perf_evlist__add(evlist, evsel);
--
Configure event list with the cpus map and open event:
[source,c]
--
62 perf_evlist__set_maps(evlist, cpus, NULL);
63
64 err = perf_evlist__open(evlist);
65 if (err) {
66 fprintf(stderr, "failed to open evlist\n");
67 goto out_evlist;
68 }
--
Once the events list is open, we can create memory maps AKA perf ring buffers:
[source,c]
--
70 err = perf_evlist__mmap(evlist, 4);
71 if (err) {
72 fprintf(stderr, "failed to mmap evlist\n");
73 goto out_evlist;
74 }
--
The event is created as disabled (note the `disabled = 1` assignment above),
so we need to enable the events list explicitely.
From this moment the cycles event is sampling.
We will sleep for 3 seconds while the ring buffers get data from all CPUs, then we disable the events list.
[source,c]
--
76 perf_evlist__enable(evlist);
77 sleep(3);
78 perf_evlist__disable(evlist);
--
Following code walks through the ring buffers and reads stored events/samples:
[source,c]
--
80 perf_evlist__for_each_mmap(evlist, map, false) {
81 if (perf_mmap__read_init(map) < 0)
82 continue;
83
84 while ((event = perf_mmap__read_event(map)) != NULL) {
/* process event */
108 perf_mmap__consume(map);
109 }
110 perf_mmap__read_done(map);
111 }
--
Each sample needs to get parsed:
[source,c]
--
85 int cpu, pid, tid;
86 __u64 ip, period, *array;
87 union u64_swap u;
88
89 array = event->sample.array;
90
91 ip = *array;
92 array++;
93
94 u.val64 = *array;
95 pid = u.val32[0];
96 tid = u.val32[1];
97 array++;
98
99 u.val64 = *array;
100 cpu = u.val32[0];
101 array++;
102
103 period = *array;
104
105 fprintf(stdout, "cpu %3d, pid %6d, tid %6d, ip %20llx, period %20llu\n",
106 cpu, pid, tid, ip, period);
--
And finaly cleanup.
We close the whole events list (both events) and remove it together with the threads map:
[source,c]
--
113 out_evlist:
114 perf_evlist__delete(evlist);
115 out_cpus:
116 perf_cpu_map__put(cpus);
117 return err;
118 }
--
REPORTING BUGS
--------------
Report bugs to <linux-perf-users@vger.kernel.org>.
LICENSE
-------
libperf is Free Software licensed under the GNU LGPL 2.1
RESOURCES
---------
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
SEE ALSO
--------
libperf(3), libperf-counting(7)
libperf(3)
==========
NAME
----
libperf - Linux kernel perf event library
SYNOPSIS
--------
*Generic API:*
[source,c]
--
#include <perf/core.h>
enum libperf_print_level {
LIBPERF_ERR,
LIBPERF_WARN,
LIBPERF_INFO,
LIBPERF_DEBUG,
LIBPERF_DEBUG2,
LIBPERF_DEBUG3,
};
typedef int (*libperf_print_fn_t)(enum libperf_print_level level,
const char *, va_list ap);
void libperf_init(libperf_print_fn_t fn);
--
*API to handle cpu maps:*
[source,c]
--
#include <perf/cpumap.h>
struct perf_cpu_map;
struct perf_cpu_map *perf_cpu_map__dummy_new(void);
struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list);
struct perf_cpu_map *perf_cpu_map__read(FILE *file);
struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map);
struct perf_cpu_map *perf_cpu_map__merge(struct perf_cpu_map *orig,
struct perf_cpu_map *other);
void perf_cpu_map__put(struct perf_cpu_map *map);
int perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx);
int perf_cpu_map__nr(const struct perf_cpu_map *cpus);
bool perf_cpu_map__empty(const struct perf_cpu_map *map);
int perf_cpu_map__max(struct perf_cpu_map *map);
#define perf_cpu_map__for_each_cpu(cpu, idx, cpus)
--
*API to handle thread maps:*
[source,c]
--
#include <perf/threadmap.h>
struct perf_thread_map;
struct perf_thread_map *perf_thread_map__new_dummy(void);
void perf_thread_map__set_pid(struct perf_thread_map *map, int thread, pid_t pid);
char *perf_thread_map__comm(struct perf_thread_map *map, int thread);
int perf_thread_map__nr(struct perf_thread_map *threads);
pid_t perf_thread_map__pid(struct perf_thread_map *map, int thread);
struct perf_thread_map *perf_thread_map__get(struct perf_thread_map *map);
void perf_thread_map__put(struct perf_thread_map *map);
--
*API to handle event lists:*
[source,c]
--
#include <perf/evlist.h>
struct perf_evlist;
void perf_evlist__add(struct perf_evlist *evlist,
struct perf_evsel *evsel);
void perf_evlist__remove(struct perf_evlist *evlist,
struct perf_evsel *evsel);
struct perf_evlist *perf_evlist__new(void);
void perf_evlist__delete(struct perf_evlist *evlist);
struct perf_evsel* perf_evlist__next(struct perf_evlist *evlist,
struct perf_evsel *evsel);
int perf_evlist__open(struct perf_evlist *evlist);
void perf_evlist__close(struct perf_evlist *evlist);
void perf_evlist__enable(struct perf_evlist *evlist);
void perf_evlist__disable(struct perf_evlist *evlist);
#define perf_evlist__for_each_evsel(evlist, pos)
void perf_evlist__set_maps(struct perf_evlist *evlist,
struct perf_cpu_map *cpus,
struct perf_thread_map *threads);
int perf_evlist__poll(struct perf_evlist *evlist, int timeout);
int perf_evlist__filter_pollfd(struct perf_evlist *evlist,
short revents_and_mask);
int perf_evlist__mmap(struct perf_evlist *evlist, int pages);
void perf_evlist__munmap(struct perf_evlist *evlist);
struct perf_mmap *perf_evlist__next_mmap(struct perf_evlist *evlist,
struct perf_mmap *map,
bool overwrite);
#define perf_evlist__for_each_mmap(evlist, pos, overwrite)
--
*API to handle events:*
[source,c]
--
#include <perf/evsel.h>*
struct perf_evsel;
struct perf_counts_values {
union {
struct {
uint64_t val;
uint64_t ena;
uint64_t run;
};
uint64_t values[3];
};
};
struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr);
void perf_evsel__delete(struct perf_evsel *evsel);
int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
struct perf_thread_map *threads);
void perf_evsel__close(struct perf_evsel *evsel);
void perf_evsel__close_cpu(struct perf_evsel *evsel, int cpu);
int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread,
struct perf_counts_values *count);
int perf_evsel__enable(struct perf_evsel *evsel);
int perf_evsel__enable_cpu(struct perf_evsel *evsel, int cpu);
int perf_evsel__disable(struct perf_evsel *evsel);
int perf_evsel__disable_cpu(struct perf_evsel *evsel, int cpu);
struct perf_cpu_map *perf_evsel__cpus(struct perf_evsel *evsel);
struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel);
struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel);
--
*API to handle maps (perf ring buffers):*
[source,c]
--
#include <perf/mmap.h>
struct perf_mmap;
void perf_mmap__consume(struct perf_mmap *map);
int perf_mmap__read_init(struct perf_mmap *map);
void perf_mmap__read_done(struct perf_mmap *map);
union perf_event *perf_mmap__read_event(struct perf_mmap *map);
--
*Structures to access perf API events:*
[source,c]
--
#include <perf/event.h>
struct perf_record_mmap;
struct perf_record_mmap2;
struct perf_record_comm;
struct perf_record_namespaces;
struct perf_record_fork;
struct perf_record_lost;
struct perf_record_lost_samples;
struct perf_record_read;
struct perf_record_throttle;
struct perf_record_ksymbol;
struct perf_record_bpf_event;
struct perf_record_sample;
struct perf_record_switch;
struct perf_record_header_attr;
struct perf_record_record_cpu_map;
struct perf_record_cpu_map_data;
struct perf_record_cpu_map;
struct perf_record_event_update_cpus;
struct perf_record_event_update_scale;
struct perf_record_event_update;
struct perf_trace_event_type;
struct perf_record_header_event_type;
struct perf_record_header_tracing_data;
struct perf_record_header_build_id;
struct perf_record_id_index;
struct perf_record_auxtrace_info;
struct perf_record_auxtrace;
struct perf_record_auxtrace_error;
struct perf_record_aux;
struct perf_record_itrace_start;
struct perf_record_thread_map_entry;
struct perf_record_thread_map;
struct perf_record_stat_config_entry;
struct perf_record_stat_config;
struct perf_record_stat;
struct perf_record_stat_round;
struct perf_record_time_conv;
struct perf_record_header_feature;
struct perf_record_compressed;
--
DESCRIPTION
-----------
The libperf library provides an API to access the linux kernel perf
events subsystem.
Following objects are key to the libperf interface:
[horizontal]
struct perf_cpu_map:: Provides a cpu list abstraction.
struct perf_thread_map:: Provides a thread list abstraction.
struct perf_evsel:: Provides an abstraction for single a perf event.
struct perf_evlist:: Gathers several struct perf_evsel object and performs functions on all of them.
struct perf_mmap:: Provides an abstraction for accessing perf ring buffer.
The exported API functions bind these objects together.
REPORTING BUGS
--------------
Report bugs to <linux-perf-users@vger.kernel.org>.
LICENSE
-------
libperf is Free Software licensed under the GNU LGPL 2.1
RESOURCES
---------
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
SEE ALSO
--------
libperf-sampling(7), libperf-counting(7)
.. SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
libperf
The libperf library provides an API to access the linux kernel perf
events subsystem. It provides the following high level objects:
- struct perf_cpu_map
- struct perf_thread_map
- struct perf_evlist
- struct perf_evsel
reference
=========
Function reference by header files:
perf/core.h
-----------
.. code-block:: c
typedef int (\*libperf_print_fn_t)(enum libperf_print_level level,
const char \*, va_list ap);
void libperf_set_print(libperf_print_fn_t fn);
perf/cpumap.h
-------------
.. code-block:: c
struct perf_cpu_map \*perf_cpu_map__dummy_new(void);
struct perf_cpu_map \*perf_cpu_map__new(const char \*cpu_list);
struct perf_cpu_map \*perf_cpu_map__read(FILE \*file);
struct perf_cpu_map \*perf_cpu_map__get(struct perf_cpu_map \*map);
void perf_cpu_map__put(struct perf_cpu_map \*map);
int perf_cpu_map__cpu(const struct perf_cpu_map \*cpus, int idx);
int perf_cpu_map__nr(const struct perf_cpu_map \*cpus);
perf_cpu_map__for_each_cpu(cpu, idx, cpus)
perf/threadmap.h
----------------
.. code-block:: c
struct perf_thread_map \*perf_thread_map__new_dummy(void);
void perf_thread_map__set_pid(struct perf_thread_map \*map, int thread, pid_t pid);
char \*perf_thread_map__comm(struct perf_thread_map \*map, int thread);
struct perf_thread_map \*perf_thread_map__get(struct perf_thread_map \*map);
void perf_thread_map__put(struct perf_thread_map \*map);
perf/evlist.h
-------------
.. code-block::
void perf_evlist__init(struct perf_evlist \*evlist);
void perf_evlist__add(struct perf_evlist \*evlist,
struct perf_evsel \*evsel);
void perf_evlist__remove(struct perf_evlist \*evlist,
struct perf_evsel \*evsel);
struct perf_evlist \*perf_evlist__new(void);
void perf_evlist__delete(struct perf_evlist \*evlist);
struct perf_evsel\* perf_evlist__next(struct perf_evlist \*evlist,
struct perf_evsel \*evsel);
int perf_evlist__open(struct perf_evlist \*evlist);
void perf_evlist__close(struct perf_evlist \*evlist);
void perf_evlist__enable(struct perf_evlist \*evlist);
void perf_evlist__disable(struct perf_evlist \*evlist);
perf_evlist__for_each_evsel(evlist, pos)
void perf_evlist__set_maps(struct perf_evlist \*evlist,
struct perf_cpu_map \*cpus,
struct perf_thread_map \*threads);
perf/evsel.h
------------
.. code-block:: c
struct perf_counts_values {
union {
struct {
uint64_t val;
uint64_t ena;
uint64_t run;
};
uint64_t values[3];
};
};
void perf_evsel__init(struct perf_evsel \*evsel,
struct perf_event_attr \*attr);
struct perf_evsel \*perf_evsel__new(struct perf_event_attr \*attr);
void perf_evsel__delete(struct perf_evsel \*evsel);
int perf_evsel__open(struct perf_evsel \*evsel, struct perf_cpu_map \*cpus,
struct perf_thread_map \*threads);
void perf_evsel__close(struct perf_evsel \*evsel);
int perf_evsel__read(struct perf_evsel \*evsel, int cpu, int thread,
struct perf_counts_values \*count);
int perf_evsel__enable(struct perf_evsel \*evsel);
int perf_evsel__disable(struct perf_evsel \*evsel);
int perf_evsel__apply_filter(struct perf_evsel \*evsel, const char \*filter);
struct perf_cpu_map \*perf_evsel__cpus(struct perf_evsel \*evsel);
struct perf_thread_map \*perf_evsel__threads(struct perf_evsel \*evsel);
struct perf_event_attr \*perf_evsel__attr(struct perf_evsel \*evsel);
<!-- manpage-1.72.xsl:
special settings for manpages rendered from asciidoc+docbook
handles peculiarities in docbook-xsl 1.72.0 -->
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<xsl:import href="manpage-base.xsl"/>
<!-- these are the special values for the roff control characters
needed for docbook-xsl 1.72.0 -->
<xsl:param name="git.docbook.backslash">&#x2593;</xsl:param>
<xsl:param name="git.docbook.dot" >&#x2302;</xsl:param>
</xsl:stylesheet>
<!-- manpage-base.xsl:
special formatting for manpages rendered from asciidoc+docbook -->
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<!-- these params silence some output from xmlto -->
<xsl:param name="man.output.quietly" select="1"/>
<xsl:param name="refentry.meta.get.quietly" select="1"/>
<!-- convert asciidoc callouts to man page format;
git.docbook.backslash and git.docbook.dot params
must be supplied by another XSL file or other means -->
<xsl:template match="co">
<xsl:value-of select="concat(
$git.docbook.backslash,'fB(',
substring-after(@id,'-'),')',
$git.docbook.backslash,'fR')"/>
</xsl:template>
<xsl:template match="calloutlist">
<xsl:value-of select="$git.docbook.dot"/>
<xsl:text>sp&#10;</xsl:text>
<xsl:apply-templates/>
<xsl:text>&#10;</xsl:text>
</xsl:template>
<xsl:template match="callout">
<xsl:value-of select="concat(
$git.docbook.backslash,'fB',
substring-after(@arearefs,'-'),
'. ',$git.docbook.backslash,'fR')"/>
<xsl:apply-templates/>
<xsl:value-of select="$git.docbook.dot"/>
<xsl:text>br&#10;</xsl:text>
</xsl:template>
</xsl:stylesheet>
<!-- manpage-bold-literal.xsl:
special formatting for manpages rendered from asciidoc+docbook -->
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<!-- render literal text as bold (instead of plain or monospace);
this makes literal text easier to distinguish in manpages
viewed on a tty -->
<xsl:template match="literal">
<xsl:value-of select="$git.docbook.backslash"/>
<xsl:text>fB</xsl:text>
<xsl:apply-templates/>
<xsl:value-of select="$git.docbook.backslash"/>
<xsl:text>fR</xsl:text>
</xsl:template>
</xsl:stylesheet>
<!-- manpage-normal.xsl:
special settings for manpages rendered from asciidoc+docbook
handles anything we want to keep away from docbook-xsl 1.72.0 -->
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<xsl:import href="manpage-base.xsl"/>
<!-- these are the normal values for the roff control characters -->
<xsl:param name="git.docbook.backslash">\</xsl:param>
<xsl:param name="git.docbook.dot" >.</xsl:param>
</xsl:stylesheet>
<!-- manpage-suppress-sp.xsl:
special settings for manpages rendered from asciidoc+docbook
handles erroneous, inline .sp in manpage output of some
versions of docbook-xsl -->
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<!-- attempt to work around spurious .sp at the tail of the line
that some versions of docbook stylesheets seem to add -->
<xsl:template match="simpara">
<xsl:variable name="content">
<xsl:apply-templates/>
</xsl:variable>
<xsl:value-of select="normalize-space($content)"/>
<xsl:if test="not(ancestor::authorblurb) and
not(ancestor::personblurb)">
<xsl:text>&#10;&#10;</xsl:text>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
.. SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
libperf tutorial
================
Compile and install libperf from kernel sources
===============================================
.. code-block:: bash
git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
cd linux/tools/perf/lib
make
sudo make install prefix=/usr
Libperf object
==============
The libperf library provides several high level objects:
struct perf_cpu_map
Provides a cpu list abstraction.
struct perf_thread_map
Provides a thread list abstraction.
struct perf_evsel
Provides an abstraction for single a perf event.
struct perf_evlist
Gathers several struct perf_evsel object and performs functions on all of them.
The exported API binds these objects together,
for full reference see the libperf.7 man page.
Examples
========
Examples aim to explain libperf functionality on simple use cases.
They are based in on a checked out linux kernel git tree:
.. code-block:: bash
$ cd tools/perf/lib/Documentation/tutorial/
$ ls -d ex-*
ex-1-compile ex-2-evsel-stat ex-3-evlist-stat
ex-1-compile example
====================
This example shows the basic usage of *struct perf_cpu_map*,
how to create it and display its cpus:
.. code-block:: bash
$ cd ex-1-compile/
$ make
gcc -o test test.c -lperf
$ ./test
0 1 2 3 4 5 6 7
The full code listing is here:
.. code-block:: c
1 #include <perf/cpumap.h>
2
3 int main(int argc, char **Argv)
4 {
5 struct perf_cpu_map *cpus;
6 int cpu, tmp;
7
8 cpus = perf_cpu_map__new(NULL);
9
10 perf_cpu_map__for_each_cpu(cpu, tmp, cpus)
11 fprintf(stdout, "%d ", cpu);
12
13 fprintf(stdout, "\n");
14
15 perf_cpu_map__put(cpus);
16 return 0;
17 }
First you need to include the proper header to have *struct perf_cpumap*
declaration and functions:
.. code-block:: c
1 #include <perf/cpumap.h>
The *struct perf_cpumap* object is created by *perf_cpu_map__new* call.
The *NULL* argument asks it to populate the object with the current online CPUs list:
.. code-block:: c
8 cpus = perf_cpu_map__new(NULL);
This is paired with a *perf_cpu_map__put*, that drops its reference at the end, possibly deleting it.
.. code-block:: c
15 perf_cpu_map__put(cpus);
The iteration through the *struct perf_cpumap* CPUs is done using the *perf_cpu_map__for_each_cpu*
macro which requires 3 arguments:
- cpu - the cpu numer
- tmp - iteration helper variable
- cpus - the *struct perf_cpumap* object
.. code-block:: c
10 perf_cpu_map__for_each_cpu(cpu, tmp, cpus)
11 fprintf(stdout, "%d ", cpu);
ex-2-evsel-stat example
=======================
TBD
ex-3-evlist-stat example
========================
TBD
...@@ -181,7 +181,10 @@ install_pkgconfig: $(LIBPERF_PC) ...@@ -181,7 +181,10 @@ install_pkgconfig: $(LIBPERF_PC)
$(call QUIET_INSTALL, $(LIBPERF_PC)) \ $(call QUIET_INSTALL, $(LIBPERF_PC)) \
$(call do_install,$(LIBPERF_PC),$(libdir_SQ)/pkgconfig,644) $(call do_install,$(LIBPERF_PC),$(libdir_SQ)/pkgconfig,644)
install: install_lib install_headers install_pkgconfig install_doc:
$(Q)$(MAKE) -C Documentation install-man install-html install-examples
install: install_lib install_headers install_pkgconfig install_doc
FORCE: FORCE:
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment