remarkable-linux/tools/perf/builtin-report.c
Arnaldo Carvalho de Melo ec80fde746 perf symbols: Handle /proc/sys/kernel/kptr_restrict
Perf uses /proc/modules to figure out where kernel modules are loaded.

With the advent of kptr_restrict, non root users get zeroes for all module
start addresses.

So check if kptr_restrict is non zero and don't generate the syntethic
PERF_RECORD_MMAP events for them.

Warn the user about it in perf record and in perf report.

In perf report the reference relocation symbol being zero means that
kptr_restrict was set, thus /proc/kallsyms has only zeroed addresses, so don't
use it to fixup symbol addresses when using a valid kallsyms (in the buildid
cache) or vmlinux (in the vmlinux path) build-id located automatically or
specified by the user.

Provide an explanation about it in 'perf report' if kernel samples were taken,
checking if a suitable vmlinux or kallsyms was found/specified.

Restricted /proc/kallsyms don't go to the buildid cache anymore.

Example:

 [acme@emilia ~]$ perf record -F 100000 sleep 1

 WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted, check
 /proc/sys/kernel/kptr_restrict.

 Samples in kernel functions may not be resolved if a suitable vmlinux file is
 not found in the buildid cache or in the vmlinux path.

 Samples in kernel modules won't be resolved at all.

 If some relocation was applied (e.g. kexec) symbols may be misresolved even
 with a suitable vmlinux or kallsyms file.

 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.005 MB perf.data (~231 samples) ]
 [acme@emilia ~]$

 [acme@emilia ~]$ perf report --stdio
 Kernel address maps (/proc/{kallsyms,modules}) were restricted,
 check /proc/sys/kernel/kptr_restrict before running 'perf record'.

 If some relocation was applied (e.g. kexec) symbols may be misresolved.

 Samples in kernel modules can't be resolved as well.

 # Events: 13  cycles
 #
 # Overhead  Command      Shared Object                 Symbol
 # ........  .......  .................  .....................
 #
    20.24%    sleep  [kernel.kallsyms]  [k] page_fault
    20.04%    sleep  [kernel.kallsyms]  [k] filemap_fault
    19.78%    sleep  [kernel.kallsyms]  [k] __lru_cache_add
    19.69%    sleep  ld-2.12.so         [.] memcpy
    14.71%    sleep  [kernel.kallsyms]  [k] dput
     4.70%    sleep  [kernel.kallsyms]  [k] flush_signal_handlers
     0.73%    sleep  [kernel.kallsyms]  [k] perf_event_comm
     0.11%    sleep  [kernel.kallsyms]  [k] native_write_msr_safe

 #
 # (For a higher level overview, try: perf report --sort comm,dso)
 #
 [acme@emilia ~]$

This is because it found a suitable vmlinux (build-id checked) in
/lib/modules/2.6.39-rc7+/build/vmlinux (use -v in perf report to see the long
file name).

If we remove that file from the vmlinux path:

 [root@emilia ~]# mv /lib/modules/2.6.39-rc7+/build/vmlinux \
		     /lib/modules/2.6.39-rc7+/build/vmlinux.OFF
 [acme@emilia ~]$ perf report --stdio
 [kernel.kallsyms] with build id 57298cdbe0131f6871667ec0eaab4804dcf6f562
 not found, continuing without symbols

 Kernel address maps (/proc/{kallsyms,modules}) were restricted, check
 /proc/sys/kernel/kptr_restrict before running 'perf record'.

 As no suitable kallsyms nor vmlinux was found, kernel samples can't be
 resolved.

 Samples in kernel modules can't be resolved as well.

 # Events: 13  cycles
 #
 # Overhead  Command      Shared Object  Symbol
 # ........  .......  .................  ......
 #
    80.31%    sleep  [kernel.kallsyms]  [k] 0xffffffff8103425a
    19.69%    sleep  ld-2.12.so         [.] memcpy

 #
 # (For a higher level overview, try: perf report --sort comm,dso)
 #
 [acme@emilia ~]$

Reported-by: Stephane Eranian <eranian@google.com>
Suggested-by: David Miller <davem@davemloft.net>
Cc: Dave Jones <davej@redhat.com>
Cc: David Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Link: http://lkml.kernel.org/n/tip-mt512joaxxbhhp1odop04yit@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-05-26 11:15:25 -03:00

526 lines
14 KiB
C

/*
* builtin-report.c
*
* Builtin report command: Analyze the perf.data input file,
* look up and read DSOs and symbol information and display
* a histogram of results, along various sorting keys.
*/
#include "builtin.h"
#include "util/util.h"
#include "util/annotate.h"
#include "util/color.h"
#include <linux/list.h>
#include "util/cache.h"
#include <linux/rbtree.h>
#include "util/symbol.h"
#include "util/callchain.h"
#include "util/strlist.h"
#include "util/values.h"
#include "perf.h"
#include "util/debug.h"
#include "util/evlist.h"
#include "util/evsel.h"
#include "util/header.h"
#include "util/session.h"
#include "util/parse-options.h"
#include "util/parse-events.h"
#include "util/thread.h"
#include "util/sort.h"
#include "util/hist.h"
static char const *input_name = "perf.data";
static bool force, use_tui, use_stdio;
static bool hide_unresolved;
static bool dont_use_callchains;
static bool show_threads;
static struct perf_read_values show_threads_values;
static const char default_pretty_printing_style[] = "normal";
static const char *pretty_printing_style = default_pretty_printing_style;
static char callchain_default_opt[] = "fractal,0.5";
static symbol_filter_t annotate_init;
static int perf_session__add_hist_entry(struct perf_session *session,
struct addr_location *al,
struct perf_sample *sample,
struct perf_evsel *evsel)
{
struct symbol *parent = NULL;
int err = 0;
struct hist_entry *he;
if ((sort__has_parent || symbol_conf.use_callchain) && sample->callchain) {
err = perf_session__resolve_callchain(session, al->thread,
sample->callchain, &parent);
if (err)
return err;
}
he = __hists__add_entry(&evsel->hists, al, parent, sample->period);
if (he == NULL)
return -ENOMEM;
if (symbol_conf.use_callchain) {
err = callchain_append(he->callchain, &session->callchain_cursor,
sample->period);
if (err)
return err;
}
/*
* Only in the newt browser we are doing integrated annotation,
* so we don't allocated the extra space needed because the stdio
* code will not use it.
*/
if (al->sym != NULL && use_browser > 0) {
struct annotation *notes = symbol__annotation(he->ms.sym);
assert(evsel != NULL);
err = -ENOMEM;
if (notes->src == NULL &&
symbol__alloc_hist(he->ms.sym, session->evlist->nr_entries) < 0)
goto out;
err = hist_entry__inc_addr_samples(he, evsel->idx, al->addr);
}
evsel->hists.stats.total_period += sample->period;
hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);
out:
return err;
}
static int process_sample_event(union perf_event *event,
struct perf_sample *sample,
struct perf_evsel *evsel,
struct perf_session *session)
{
struct addr_location al;
if (perf_event__preprocess_sample(event, session, &al, sample,
annotate_init) < 0) {
fprintf(stderr, "problem processing %d event, skipping it.\n",
event->header.type);
return -1;
}
if (al.filtered || (hide_unresolved && al.sym == NULL))
return 0;
if (al.map != NULL)
al.map->dso->hit = 1;
if (perf_session__add_hist_entry(session, &al, sample, evsel)) {
pr_debug("problem incrementing symbol period, skipping event\n");
return -1;
}
return 0;
}
static int process_read_event(union perf_event *event,
struct perf_sample *sample __used,
struct perf_session *session)
{
struct perf_evsel *evsel = perf_evlist__id2evsel(session->evlist,
event->read.id);
if (show_threads) {
const char *name = evsel ? event_name(evsel) : "unknown";
perf_read_values_add_value(&show_threads_values,
event->read.pid, event->read.tid,
event->read.id,
name,
event->read.value);
}
dump_printf(": %d %d %s %" PRIu64 "\n", event->read.pid, event->read.tid,
evsel ? event_name(evsel) : "FAIL",
event->read.value);
return 0;
}
static int perf_session__setup_sample_type(struct perf_session *self)
{
if (!(self->sample_type & PERF_SAMPLE_CALLCHAIN)) {
if (sort__has_parent) {
fprintf(stderr, "selected --sort parent, but no"
" callchain data. Did you call"
" perf record without -g?\n");
return -EINVAL;
}
if (symbol_conf.use_callchain) {
fprintf(stderr, "selected -g but no callchain data."
" Did you call perf record without"
" -g?\n");
return -1;
}
} else if (!dont_use_callchains && callchain_param.mode != CHAIN_NONE &&
!symbol_conf.use_callchain) {
symbol_conf.use_callchain = true;
if (callchain_register_param(&callchain_param) < 0) {
fprintf(stderr, "Can't register callchain"
" params\n");
return -EINVAL;
}
}
return 0;
}
static struct perf_event_ops event_ops = {
.sample = process_sample_event,
.mmap = perf_event__process_mmap,
.comm = perf_event__process_comm,
.exit = perf_event__process_task,
.fork = perf_event__process_task,
.lost = perf_event__process_lost,
.read = process_read_event,
.attr = perf_event__process_attr,
.event_type = perf_event__process_event_type,
.tracing_data = perf_event__process_tracing_data,
.build_id = perf_event__process_build_id,
.ordered_samples = true,
.ordering_requires_timestamps = true,
};
extern volatile int session_done;
static void sig_handler(int sig __used)
{
session_done = 1;
}
static size_t hists__fprintf_nr_sample_events(struct hists *self,
const char *evname, FILE *fp)
{
size_t ret;
char unit;
unsigned long nr_events = self->stats.nr_events[PERF_RECORD_SAMPLE];
nr_events = convert_unit(nr_events, &unit);
ret = fprintf(fp, "# Events: %lu%c", nr_events, unit);
if (evname != NULL)
ret += fprintf(fp, " %s", evname);
return ret + fprintf(fp, "\n#\n");
}
static int perf_evlist__tty_browse_hists(struct perf_evlist *evlist,
const char *help)
{
struct perf_evsel *pos;
list_for_each_entry(pos, &evlist->entries, node) {
struct hists *hists = &pos->hists;
const char *evname = NULL;
if (rb_first(&hists->entries) != rb_last(&hists->entries))
evname = event_name(pos);
hists__fprintf_nr_sample_events(hists, evname, stdout);
hists__fprintf(hists, NULL, false, stdout);
fprintf(stdout, "\n\n");
}
if (sort_order == default_sort_order &&
parent_pattern == default_parent_pattern) {
fprintf(stdout, "#\n# (%s)\n#\n", help);
if (show_threads) {
bool style = !strcmp(pretty_printing_style, "raw");
perf_read_values_display(stdout, &show_threads_values,
style);
perf_read_values_destroy(&show_threads_values);
}
}
return 0;
}
static int __cmd_report(void)
{
int ret = -EINVAL;
u64 nr_samples;
struct perf_session *session;
struct perf_evsel *pos;
struct map *kernel_map;
struct kmap *kernel_kmap;
const char *help = "For a higher level overview, try: perf report --sort comm,dso";
signal(SIGINT, sig_handler);
session = perf_session__new(input_name, O_RDONLY, force, false, &event_ops);
if (session == NULL)
return -ENOMEM;
if (show_threads)
perf_read_values_init(&show_threads_values);
ret = perf_session__setup_sample_type(session);
if (ret)
goto out_delete;
ret = perf_session__process_events(session, &event_ops);
if (ret)
goto out_delete;
kernel_map = session->host_machine.vmlinux_maps[MAP__FUNCTION];
kernel_kmap = map__kmap(kernel_map);
if (kernel_map == NULL ||
(kernel_map->dso->hit &&
(kernel_kmap->ref_reloc_sym == NULL ||
kernel_kmap->ref_reloc_sym->addr == 0))) {
const struct dso *kdso = kernel_map->dso;
ui__warning("Kernel address maps "
"(/proc/{kallsyms,modules}) were restricted, "
"check /proc/sys/kernel/kptr_restrict before "
"running 'perf record'.\n\n%s\n\n"
"Samples in kernel modules can't be resolved "
"as well.\n\n",
RB_EMPTY_ROOT(&kdso->symbols[MAP__FUNCTION]) ?
"As no suitable kallsyms nor vmlinux was found, "
"kernel samples can't be resolved." :
"If some relocation was applied (e.g. kexec) "
"symbols may be misresolved.");
}
if (dump_trace) {
perf_session__fprintf_nr_events(session, stdout);
goto out_delete;
}
if (verbose > 3)
perf_session__fprintf(session, stdout);
if (verbose > 2)
perf_session__fprintf_dsos(session, stdout);
nr_samples = 0;
list_for_each_entry(pos, &session->evlist->entries, node) {
struct hists *hists = &pos->hists;
hists__collapse_resort(hists);
hists__output_resort(hists);
nr_samples += hists->stats.nr_events[PERF_RECORD_SAMPLE];
}
if (nr_samples == 0) {
ui__warning("The %s file has no samples!\n", input_name);
goto out_delete;
}
if (use_browser > 0)
perf_evlist__tui_browse_hists(session->evlist, help);
else
perf_evlist__tty_browse_hists(session->evlist, help);
out_delete:
/*
* Speed up the exit process, for large files this can
* take quite a while.
*
* XXX Enable this when using valgrind or if we ever
* librarize this command.
*
* Also experiment with obstacks to see how much speed
* up we'll get here.
*
* perf_session__delete(session);
*/
return ret;
}
static int
parse_callchain_opt(const struct option *opt __used, const char *arg,
int unset)
{
char *tok, *tok2;
char *endptr;
/*
* --no-call-graph
*/
if (unset) {
dont_use_callchains = true;
return 0;
}
symbol_conf.use_callchain = true;
if (!arg)
return 0;
tok = strtok((char *)arg, ",");
if (!tok)
return -1;
/* get the output mode */
if (!strncmp(tok, "graph", strlen(arg)))
callchain_param.mode = CHAIN_GRAPH_ABS;
else if (!strncmp(tok, "flat", strlen(arg)))
callchain_param.mode = CHAIN_FLAT;
else if (!strncmp(tok, "fractal", strlen(arg)))
callchain_param.mode = CHAIN_GRAPH_REL;
else if (!strncmp(tok, "none", strlen(arg))) {
callchain_param.mode = CHAIN_NONE;
symbol_conf.use_callchain = false;
return 0;
}
else
return -1;
/* get the min percentage */
tok = strtok(NULL, ",");
if (!tok)
goto setup;
tok2 = strtok(NULL, ",");
callchain_param.min_percent = strtod(tok, &endptr);
if (tok == endptr)
return -1;
if (tok2)
callchain_param.print_limit = strtod(tok2, &endptr);
setup:
if (callchain_register_param(&callchain_param) < 0) {
fprintf(stderr, "Can't register callchain params\n");
return -1;
}
return 0;
}
static const char * const report_usage[] = {
"perf report [<options>] <command>",
NULL
};
static const struct option options[] = {
OPT_STRING('i', "input", &input_name, "file",
"input file name"),
OPT_INCR('v', "verbose", &verbose,
"be more verbose (show symbol address, etc)"),
OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
"dump raw trace in ASCII"),
OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
"file", "vmlinux pathname"),
OPT_STRING(0, "kallsyms", &symbol_conf.kallsyms_name,
"file", "kallsyms pathname"),
OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
"load module symbols - WARNING: use only with -k and LIVE kernel"),
OPT_BOOLEAN('n', "show-nr-samples", &symbol_conf.show_nr_samples,
"Show a column with the number of samples"),
OPT_BOOLEAN('T', "threads", &show_threads,
"Show per-thread event counters"),
OPT_STRING(0, "pretty", &pretty_printing_style, "key",
"pretty printing style key: normal raw"),
OPT_BOOLEAN(0, "tui", &use_tui, "Use the TUI interface"),
OPT_BOOLEAN(0, "stdio", &use_stdio, "Use the stdio interface"),
OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
"sort by key(s): pid, comm, dso, symbol, parent"),
OPT_BOOLEAN(0, "showcpuutilization", &symbol_conf.show_cpu_utilization,
"Show sample percentage for different cpu modes"),
OPT_STRING('p', "parent", &parent_pattern, "regex",
"regex filter to identify parent, see: '--sort parent'"),
OPT_BOOLEAN('x', "exclude-other", &symbol_conf.exclude_other,
"Only display entries with parent-match"),
OPT_CALLBACK_DEFAULT('g', "call-graph", NULL, "output_type,min_percent",
"Display callchains using output_type (graph, flat, fractal, or none) and min percent threshold. "
"Default: fractal,0.5", &parse_callchain_opt, callchain_default_opt),
OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
"only consider symbols in these dsos"),
OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
"only consider symbols in these comms"),
OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
"only consider these symbols"),
OPT_STRING('w', "column-widths", &symbol_conf.col_width_list_str,
"width[,width...]",
"don't try to adjust column width, use these fixed values"),
OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
"separator for columns, no spaces will be added between "
"columns '.' is reserved."),
OPT_BOOLEAN('U', "hide-unresolved", &hide_unresolved,
"Only display entries resolved to a symbol"),
OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
"Look for files with symbols relative to this directory"),
OPT_END()
};
int cmd_report(int argc, const char **argv, const char *prefix __used)
{
argc = parse_options(argc, argv, options, report_usage, 0);
if (use_stdio)
use_browser = 0;
else if (use_tui)
use_browser = 1;
if (strcmp(input_name, "-") != 0)
setup_browser(true);
else
use_browser = 0;
/*
* Only in the newt browser we are doing integrated annotation,
* so don't allocate extra space that won't be used in the stdio
* implementation.
*/
if (use_browser > 0) {
symbol_conf.priv_size = sizeof(struct annotation);
annotate_init = symbol__annotate_init;
/*
* For searching by name on the "Browse map details".
* providing it only in verbose mode not to bloat too
* much struct symbol.
*/
if (verbose) {
/*
* XXX: Need to provide a less kludgy way to ask for
* more space per symbol, the u32 is for the index on
* the ui browser.
* See symbol__browser_index.
*/
symbol_conf.priv_size += sizeof(u32);
symbol_conf.sort_by_name = true;
}
}
if (symbol__init() < 0)
return -1;
setup_sorting(report_usage, options);
if (parent_pattern != default_parent_pattern) {
if (sort_dimension__add("parent") < 0)
return -1;
sort_parent.elide = 1;
} else
symbol_conf.exclude_other = false;
/*
* Any (unrecognized) arguments left?
*/
if (argc)
usage_with_options(report_usage, options);
sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", stdout);
sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", stdout);
sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", stdout);
return __cmd_report();
}