linux/tools/perf/builtin-inject.c
Ian Munsie 21ef97f05a perf session: Fallback to unordered processing if no sample_id_all
If we are running the new perf on an old kernel without support for
sample_id_all, we should fall back to the old unordered processing of
events. If we didn't than we would *always* process events without
timestamps out of order, whether or not we hit a reordering race. In
other words, instead of there being a chance of not attributing samples
correctly, we would guarantee that samples would not be attributed.

While processing all events without timestamps before events with
timestamps may seem like an intuitive solution, it falls down as
PERF_RECORD_EXIT events would also be processed before any samples.
Even with a workaround for that case, samples before/after an exec would
not be attributed correctly.

This patch allows commands to indicate whether they need to fall back to
unordered processing, so that commands that do not care about timestamps
on every event will not be affected. If we do fallback, this will print
out a warning if report -D was invoked.

This patch adds the test in perf_session__new so that we only need to
test once per session. Commands that do not use an event_ops (such as
record and top) can simply pass NULL in it's place.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <1291951882-sup-6069@au1.ibm.com>
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-12-21 20:17:51 -02:00

238 lines
5.0 KiB
C

/*
* builtin-inject.c
*
* Builtin inject command: Examine the live mode (stdin) event stream
* and repipe it to stdout while optionally injecting additional
* events into it.
*/
#include "builtin.h"
#include "perf.h"
#include "util/session.h"
#include "util/debug.h"
#include "util/parse-options.h"
static char const *input_name = "-";
static bool inject_build_ids;
static int event__repipe_synth(event_t *event,
struct perf_session *session __used)
{
uint32_t size;
void *buf = event;
size = event->header.size;
while (size) {
int ret = write(STDOUT_FILENO, buf, size);
if (ret < 0)
return -errno;
size -= ret;
buf += ret;
}
return 0;
}
static int event__repipe(event_t *event, struct sample_data *sample __used,
struct perf_session *session)
{
return event__repipe_synth(event, session);
}
static int event__repipe_mmap(event_t *self, struct sample_data *sample,
struct perf_session *session)
{
int err;
err = event__process_mmap(self, sample, session);
event__repipe(self, sample, session);
return err;
}
static int event__repipe_task(event_t *self, struct sample_data *sample,
struct perf_session *session)
{
int err;
err = event__process_task(self, sample, session);
event__repipe(self, sample, session);
return err;
}
static int event__repipe_tracing_data(event_t *self,
struct perf_session *session)
{
int err;
event__repipe_synth(self, session);
err = event__process_tracing_data(self, session);
return err;
}
static int dso__read_build_id(struct dso *self)
{
if (self->has_build_id)
return 0;
if (filename__read_build_id(self->long_name, self->build_id,
sizeof(self->build_id)) > 0) {
self->has_build_id = true;
return 0;
}
return -1;
}
static int dso__inject_build_id(struct dso *self, struct perf_session *session)
{
u16 misc = PERF_RECORD_MISC_USER;
struct machine *machine;
int err;
if (dso__read_build_id(self) < 0) {
pr_debug("no build_id found for %s\n", self->long_name);
return -1;
}
machine = perf_session__find_host_machine(session);
if (machine == NULL) {
pr_err("Can't find machine for session\n");
return -1;
}
if (self->kernel)
misc = PERF_RECORD_MISC_KERNEL;
err = event__synthesize_build_id(self, misc, event__repipe,
machine, session);
if (err) {
pr_err("Can't synthesize build_id event for %s\n", self->long_name);
return -1;
}
return 0;
}
static int event__inject_buildid(event_t *event, struct sample_data *sample,
struct perf_session *session)
{
struct addr_location al;
struct thread *thread;
u8 cpumode;
cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
thread = perf_session__findnew(session, event->ip.pid);
if (thread == NULL) {
pr_err("problem processing %d event, skipping it.\n",
event->header.type);
goto repipe;
}
thread__find_addr_map(thread, session, cpumode, MAP__FUNCTION,
event->ip.pid, event->ip.ip, &al);
if (al.map != NULL) {
if (!al.map->dso->hit) {
al.map->dso->hit = 1;
if (map__load(al.map, NULL) >= 0) {
dso__inject_build_id(al.map->dso, session);
/*
* If this fails, too bad, let the other side
* account this as unresolved.
*/
} else
pr_warning("no symbols found in %s, maybe "
"install a debug package?\n",
al.map->dso->long_name);
}
}
repipe:
event__repipe(event, sample, session);
return 0;
}
struct perf_event_ops inject_ops = {
.sample = event__repipe,
.mmap = event__repipe,
.comm = event__repipe,
.fork = event__repipe,
.exit = event__repipe,
.lost = event__repipe,
.read = event__repipe,
.throttle = event__repipe,
.unthrottle = event__repipe,
.attr = event__repipe_synth,
.event_type = event__repipe_synth,
.tracing_data = event__repipe_synth,
.build_id = event__repipe_synth,
};
extern volatile int session_done;
static void sig_handler(int sig __attribute__((__unused__)))
{
session_done = 1;
}
static int __cmd_inject(void)
{
struct perf_session *session;
int ret = -EINVAL;
signal(SIGINT, sig_handler);
if (inject_build_ids) {
inject_ops.sample = event__inject_buildid;
inject_ops.mmap = event__repipe_mmap;
inject_ops.fork = event__repipe_task;
inject_ops.tracing_data = event__repipe_tracing_data;
}
session = perf_session__new(input_name, O_RDONLY, false, true, &inject_ops);
if (session == NULL)
return -ENOMEM;
ret = perf_session__process_events(session, &inject_ops);
perf_session__delete(session);
return ret;
}
static const char * const report_usage[] = {
"perf inject [<options>]",
NULL
};
static const struct option options[] = {
OPT_BOOLEAN('b', "build-ids", &inject_build_ids,
"Inject build-ids into the output stream"),
OPT_INCR('v', "verbose", &verbose,
"be more verbose (show build ids, etc)"),
OPT_END()
};
int cmd_inject(int argc, const char **argv, const char *prefix __used)
{
argc = parse_options(argc, argv, options, report_usage, 0);
/*
* Any (unrecognized) arguments left?
*/
if (argc)
usage_with_options(report_usage, options);
if (symbol__init() < 0)
return -1;
return __cmd_inject();
}