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linux/tools/perf/builtin-buildid-list.c
Stephane Eranian 299c345208 perf buildid-list: Work better with pipe mode
In order for perf buildid-list to work with pipe-mode files, it needs to
process buildids and event attr structs.

$ perf record -o - noploop 2 | ./perf inject -b | perf buildid-list -i - -H
noploop for 2 seconds
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.084 MB - (~3678 samples) ]
0000000000000000000000000000000000000000 [kernel.kallsyms]
3a0d0629efe74a8da3eeba372cdbd74ad9b8f5d5 /usr/local/bin/noploop

The reason [kernel.kallsyms] shows a 0 build-id comes from the
way buildids are injected in the stream.

The buildid for the kernel is provided by a BUILD_ID record. The
[kernel.kallsyms] is provided by a MMAP record. There is no clean and
obvious way to link the two, unfortunately.

In regular mode, the kernel buildid is generated from reading the ELF
image or kallsyms and perf knows to associate [kernel.kallsyms] to it.
Later on, when perf processes the [kernel.kallsyms] MMAP record, it will
already have a dso for it.

So for now, make sure perf buildid-list shows the buildids for
everything but the kernel image.

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1337081295-10303-6-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-05-22 13:03:54 -03:00

114 lines
2.8 KiB
C

/*
* builtin-buildid-list.c
*
* Builtin buildid-list command: list buildids in perf.data, in the running
* kernel and in ELF files.
*
* 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"
#include <libelf.h>
static const char *input_name;
static bool force;
static bool show_kernel;
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_BOOLEAN('k', "kernel", &show_kernel, "Show current kernel build id"),
OPT_INCR('v', "verbose", &verbose,
"be more verbose"),
OPT_END()
};
static int sysfs__fprintf_build_id(FILE *fp)
{
u8 kallsyms_build_id[BUILD_ID_SIZE];
char sbuild_id[BUILD_ID_SIZE * 2 + 1];
if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
sizeof(kallsyms_build_id)) != 0)
return -1;
build_id__sprintf(kallsyms_build_id, sizeof(kallsyms_build_id),
sbuild_id);
fprintf(fp, "%s\n", sbuild_id);
return 0;
}
static int filename__fprintf_build_id(const char *name, FILE *fp)
{
u8 build_id[BUILD_ID_SIZE];
char sbuild_id[BUILD_ID_SIZE * 2 + 1];
if (filename__read_build_id(name, build_id,
sizeof(build_id)) != sizeof(build_id))
return 0;
build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
return fprintf(fp, "%s\n", sbuild_id);
}
static int perf_session__list_build_ids(void)
{
struct perf_session *session;
elf_version(EV_CURRENT);
session = perf_session__new(input_name, O_RDONLY, force, false,
&build_id__mark_dso_hit_ops);
if (session == NULL)
return -1;
/*
* See if this is an ELF file first:
*/
if (filename__fprintf_build_id(session->filename, stdout))
goto out;
/*
* in pipe-mode, the only way to get the buildids is to parse
* the record stream. Buildids are stored as RECORD_HEADER_BUILD_ID
*/
if (with_hits || session->fd_pipe)
perf_session__process_events(session, &build_id__mark_dso_hit_ops);
perf_session__fprintf_dsos_buildid(session, stdout, with_hits);
out:
perf_session__delete(session);
return 0;
}
static int __cmd_buildid_list(void)
{
if (show_kernel)
return sysfs__fprintf_build_id(stdout);
return perf_session__list_build_ids();
}
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();
}