linux/tools/perf/builtin-buildid-list.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

62 lines
1.5 KiB
C

/*
* builtin-buildid-list.c
*
* Builtin buildid-list command: list buildids in perf.data
*
* Copyright (C) 2009, Red Hat Inc.
* Copyright (C) 2009, Arnaldo Carvalho de Melo <acme@redhat.com>
*/
#include "builtin.h"
#include "perf.h"
#include "util/build-id.h"
#include "util/cache.h"
#include "util/debug.h"
#include "util/parse-options.h"
#include "util/session.h"
#include "util/symbol.h"
static char const *input_name = "perf.data";
static bool force;
static bool with_hits;
static const char * const buildid_list_usage[] = {
"perf buildid-list [<options>]",
NULL
};
static const struct option options[] = {
OPT_BOOLEAN('H', "with-hits", &with_hits, "Show only DSOs with hits"),
OPT_STRING('i', "input", &input_name, "file",
"input file name"),
OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
OPT_INCR('v', "verbose", &verbose,
"be more verbose"),
OPT_END()
};
static int __cmd_buildid_list(void)
{
int err = -1;
struct perf_session *session;
session = perf_session__new(input_name, O_RDONLY, force, false,
&build_id__mark_dso_hit_ops);
if (session == NULL)
return -1;
if (with_hits)
perf_session__process_events(session, &build_id__mark_dso_hit_ops);
perf_session__fprintf_dsos_buildid(session, stdout, with_hits);
perf_session__delete(session);
return err;
}
int cmd_buildid_list(int argc, const char **argv, const char *prefix __used)
{
argc = parse_options(argc, argv, options, buildid_list_usage, 0);
setup_pager();
return __cmd_buildid_list();
}