linux/tools/perf/util/trace-event.c
Ian Rogers 378ef0f5d9 perf build: Use libtraceevent from the system
Remove the LIBTRACEEVENT_DYNAMIC and LIBTRACEFS_DYNAMIC make command
line variables.

If libtraceevent isn't installed or NO_LIBTRACEEVENT=1 is passed to the
build, don't compile in libtraceevent and libtracefs support.

This also disables CONFIG_TRACE that controls "perf trace".

CONFIG_LIBTRACEEVENT is used to control enablement in Build/Makefiles,
HAVE_LIBTRACEEVENT is used in C code.

Without HAVE_LIBTRACEEVENT tracepoints are disabled and as such the
commands kmem, kwork, lock, sched and timechart are removed.  The
majority of commands continue to work including "perf test".

Committer notes:

Fixed up a tools/perf/util/Build reject and added:

  #include <traceevent/event-parse.h>

to tools/perf/util/scripting-engines/trace-event-perl.c.

Committer testing:

  $ rpm -qi libtraceevent-devel
  Name        : libtraceevent-devel
  Version     : 1.5.3
  Release     : 2.fc36
  Architecture: x86_64
  Install Date: Mon 25 Jul 2022 03:20:19 PM -03
  Group       : Unspecified
  Size        : 27728
  License     : LGPLv2+ and GPLv2+
  Signature   : RSA/SHA256, Fri 15 Apr 2022 02:11:58 PM -03, Key ID 999f7cbf38ab71f4
  Source RPM  : libtraceevent-1.5.3-2.fc36.src.rpm
  Build Date  : Fri 15 Apr 2022 10:57:01 AM -03
  Build Host  : buildvm-x86-05.iad2.fedoraproject.org
  Packager    : Fedora Project
  Vendor      : Fedora Project
  URL         : https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
  Bug URL     : https://bugz.fedoraproject.org/libtraceevent
  Summary     : Development headers of libtraceevent
  Description :
  Development headers of libtraceevent-libs
  $

Default build:

  $ ldd ~/bin/perf | grep tracee
  	libtraceevent.so.1 => /lib64/libtraceevent.so.1 (0x00007f1dcaf8f000)
  $

  # perf trace -e sched:* --max-events 10
       0.000 migration/0/17 sched:sched_migrate_task(comm: "", pid: 1603763 (perf), prio: 120, dest_cpu: 1)
       0.005 migration/0/17 sched:sched_wake_idle_without_ipi(cpu: 1)
       0.011 migration/0/17 sched:sched_switch(prev_comm: "", prev_pid: 17 (migration/0), prev_state: 1, next_comm: "", next_prio: 120)
       1.173 :0/0 sched:sched_wakeup(comm: "", pid: 3138 (gnome-terminal-), prio: 120)
       1.180 :0/0 sched:sched_switch(prev_comm: "", prev_prio: 120, next_comm: "", next_pid: 3138 (gnome-terminal-), next_prio: 120)
       0.156 migration/1/21 sched:sched_migrate_task(comm: "", pid: 1603763 (perf), prio: 120, orig_cpu: 1, dest_cpu: 2)
       0.160 migration/1/21 sched:sched_wake_idle_without_ipi(cpu: 2)
       0.166 migration/1/21 sched:sched_switch(prev_comm: "", prev_pid: 21 (migration/1), prev_state: 1, next_comm: "", next_prio: 120)
       1.183 :0/0 sched:sched_wakeup(comm: "", pid: 1602985 (kworker/u16:0-f), prio: 120, target_cpu: 1)
       1.186 :0/0 sched:sched_switch(prev_comm: "", prev_prio: 120, next_comm: "", next_pid: 1602985 (kworker/u16:0-f), next_prio: 120)
  #

Had to tweak tools/perf/util/setup.py to make sure the python binding
shared object links with libtraceevent if -DHAVE_LIBTRACEEVENT is
present in CFLAGS.

Building with NO_LIBTRACEEVENT=1 uncovered some more build failures:

- Make building of data-convert-bt.c to CONFIG_LIBTRACEEVENT=y

- perf-$(CONFIG_LIBTRACEEVENT) += scripts/

- bpf_kwork.o needs also to be dependent on CONFIG_LIBTRACEEVENT=y

- The python binding needed some fixups and util/trace-event.c can't be
  built and linked with the python binding shared object, so remove it
  in tools/perf/util/setup.py and exclude it from the list of
  dependencies in the python/perf.so Makefile.perf target.

Building without libtraceevent-devel installed uncovered more build
failures:

- The python binding tools/perf/util/python.c was assuming that
  traceevent/parse-events.h was always available, which was the case
  when we defaulted to using the in-kernel tools/lib/traceevent/ files,
  now we need to enclose it under ifdef HAVE_LIBTRACEEVENT, just like
  the other parts of it that deal with tracepoints.

- We have to ifdef the rules in the Build files with
  CONFIG_LIBTRACEEVENT=y to build builtin-trace.c and
  tools/perf/trace/beauty/ as we only ifdef setting CONFIG_TRACE=y when
  setting NO_LIBTRACEEVENT=1 in the make command line, not when we don't
  detect libtraceevent-devel installed in the system. Simplification here
  to avoid these two ways of disabling builtin-trace.c and not having
  CONFIG_TRACE=y when libtraceevent-devel isn't installed is the clean
  way.

From Athira:

<quote>
tools/perf/arch/powerpc/util/Build
-perf-y += kvm-stat.o
+perf-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o
</quote>

Then, ditto for arm64 and s390, detected by container cross build tests.

- s/390 uses test__checkevent_tracepoint() that is now only available if
  HAVE_LIBTRACEEVENT is defined, enclose the callsite with ifder HAVE_LIBTRACEEVENT.

Also from Athira:

<quote>
With this change, I could successfully compile in these environment:
- Without libtraceevent-devel installed
- With libtraceevent-devel installed
- With “make NO_LIBTRACEEVENT=1”
</quote>

Then, finally rename CONFIG_TRACEEVENT to CONFIG_LIBTRACEEVENT for
consistency with other libraries detected in tools/perf/.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20221205225940.3079667-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-12-14 11:16:12 -03:00

119 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <traceevent/event-parse.h>
#include <api/fs/tracing_path.h>
#include <api/fs/fs.h>
#include "trace-event.h"
#include "machine.h"
/*
* global trace_event object used by trace_event__tp_format
*
* TODO There's no cleanup call for this. Add some sort of
* __exit function support and call trace_event__cleanup
* there.
*/
static struct trace_event tevent;
static bool tevent_initialized;
int trace_event__init(struct trace_event *t)
{
struct tep_handle *pevent = tep_alloc();
if (pevent) {
t->plugin_list = tep_load_plugins(pevent);
t->pevent = pevent;
}
return pevent ? 0 : -1;
}
static int trace_event__init2(void)
{
int be = tep_is_bigendian();
struct tep_handle *pevent;
if (trace_event__init(&tevent))
return -1;
pevent = tevent.pevent;
tep_set_flag(pevent, TEP_NSEC_OUTPUT);
tep_set_file_bigendian(pevent, be);
tep_set_local_bigendian(pevent, be);
tevent_initialized = true;
return 0;
}
int trace_event__register_resolver(struct machine *machine,
tep_func_resolver_t *func)
{
if (!tevent_initialized && trace_event__init2())
return -1;
return tep_set_function_resolver(tevent.pevent, func, machine);
}
void trace_event__cleanup(struct trace_event *t)
{
tep_unload_plugins(t->plugin_list, t->pevent);
tep_free(t->pevent);
}
/*
* Returns pointer with encoded error via <linux/err.h> interface.
*/
static struct tep_event*
tp_format(const char *sys, const char *name)
{
char *tp_dir = get_events_file(sys);
struct tep_handle *pevent = tevent.pevent;
struct tep_event *event = NULL;
char path[PATH_MAX];
size_t size;
char *data;
int err;
if (!tp_dir)
return ERR_PTR(-errno);
scnprintf(path, PATH_MAX, "%s/%s/format", tp_dir, name);
put_events_file(tp_dir);
err = filename__read_str(path, &data, &size);
if (err)
return ERR_PTR(err);
tep_parse_format(pevent, &event, data, size, sys);
free(data);
return event;
}
/*
* Returns pointer with encoded error via <linux/err.h> interface.
*/
struct tep_event*
trace_event__tp_format(const char *sys, const char *name)
{
if (!tevent_initialized && trace_event__init2())
return ERR_PTR(-ENOMEM);
return tp_format(sys, name);
}
struct tep_event *trace_event__tp_format_id(int id)
{
if (!tevent_initialized && trace_event__init2())
return ERR_PTR(-ENOMEM);
return tep_find_event(tevent.pevent, id);
}