perf hists browser: Warn about lost events

Just like the old perf top --tui and the --stdio version.

But because we have the initial menu to choose which event to show in a
session with multiple events we can see how many chunks were lost in
each of the event types, clarifying which events are being affected the
most.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-47yyqbubmjzch2chezmb21m6@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 1ca4ff41
......@@ -89,6 +89,7 @@ static bool vmlinux_warned;
static bool inherit = false;
static int realtime_prio = 0;
static bool group = false;
static bool sample_id_all_avail = true;
static unsigned int mmap_pages = 128;
static bool dump_symtab = false;
......@@ -289,11 +290,13 @@ static void print_sym_table(void)
printf("%-*.*s\n", win_width, win_width, graph_dotted_line);
if (top.total_lost_warned != top.session->hists.stats.total_lost) {
top.total_lost_warned = top.session->hists.stats.total_lost;
color_fprintf(stdout, PERF_COLOR_RED, "WARNING:");
printf(" LOST %" PRIu64 " events, Check IO/CPU overload\n",
top.total_lost_warned);
if (top.sym_evsel->hists.stats.nr_lost_warned !=
top.sym_evsel->hists.stats.nr_events[PERF_RECORD_LOST]) {
top.sym_evsel->hists.stats.nr_lost_warned =
top.sym_evsel->hists.stats.nr_events[PERF_RECORD_LOST];
color_fprintf(stdout, PERF_COLOR_RED,
"WARNING: LOST %d chunks, Check IO/CPU overload",
top.sym_evsel->hists.stats.nr_lost_warned);
++printed;
}
......@@ -671,6 +674,7 @@ static int symbol_filter(struct map *map __used, struct symbol *sym)
}
static void perf_event__process_sample(const union perf_event *event,
struct perf_evsel *evsel,
struct perf_sample *sample,
struct perf_session *session)
{
......@@ -770,12 +774,8 @@ static void perf_event__process_sample(const union perf_event *event,
}
if (al.sym == NULL || !al.sym->ignore) {
struct perf_evsel *evsel;
struct hist_entry *he;
evsel = perf_evlist__id2evsel(top.evlist, sample->id);
assert(evsel != NULL);
if ((sort__has_parent || symbol_conf.use_callchain) &&
sample->callchain) {
err = perf_session__resolve_callchain(session, al.thread,
......@@ -807,6 +807,7 @@ static void perf_event__process_sample(const union perf_event *event,
static void perf_session__mmap_read_idx(struct perf_session *self, int idx)
{
struct perf_sample sample;
struct perf_evsel *evsel;
union perf_event *event;
int ret;
......@@ -817,10 +818,16 @@ static void perf_session__mmap_read_idx(struct perf_session *self, int idx)
continue;
}
evsel = perf_evlist__id2evsel(self->evlist, sample.id);
assert(evsel != NULL);
if (event->header.type == PERF_RECORD_SAMPLE)
perf_event__process_sample(event, &sample, self);
else
perf_event__process_sample(event, evsel, &sample, self);
else if (event->header.type < PERF_RECORD_MAX) {
hists__inc_nr_events(&evsel->hists, event->header.type);
perf_event__process(event, &sample, self);
} else
++self->hists.stats.nr_unknown_events;
}
}
......@@ -864,6 +871,8 @@ static void start_counters(struct perf_evlist *evlist)
attr->mmap = 1;
attr->comm = 1;
attr->inherit = inherit;
retry_sample_id:
attr->sample_id_all = sample_id_all_avail ? 1 : 0;
try_again:
if (perf_evsel__open(counter, top.evlist->cpus,
top.evlist->threads, group,
......@@ -873,6 +882,12 @@ static void start_counters(struct perf_evlist *evlist)
if (err == EPERM || err == EACCES) {
ui__error_paranoid();
goto out_err;
} else if (err == EINVAL && sample_id_all_avail) {
/*
* Old kernel, no attr->sample_id_type_all field
*/
sample_id_all_avail = false;
goto retry_sample_id;
}
/*
* If it's cycles then fall back to hrtimer
......
......@@ -28,6 +28,7 @@ struct events_stats {
u64 total_lost;
u64 total_invalid_chains;
u32 nr_events[PERF_RECORD_HEADER_MAX];
u32 nr_lost_warned;
u32 nr_unknown_events;
u32 nr_invalid_chains;
u32 nr_unknown_id;
......
......@@ -738,10 +738,27 @@ static int perf_session_deliver_event(struct perf_session *session,
dump_event(session, event, file_offset, sample);
evsel = perf_evlist__id2evsel(session->evlist, sample->id);
if (evsel != NULL && event->header.type != PERF_RECORD_SAMPLE) {
/*
* XXX We're leaving PERF_RECORD_SAMPLE unnacounted here
* because the tools right now may apply filters, discarding
* some of the samples. For consistency, in the future we
* should have something like nr_filtered_samples and remove
* the sample->period from total_sample_period, etc, KISS for
* now tho.
*
* Also testing against NULL allows us to handle files without
* attr.sample_id_all and/or without PERF_SAMPLE_ID. In the
* future probably it'll be a good idea to restrict event
* processing via perf_session to files with both set.
*/
hists__inc_nr_events(&evsel->hists, event->header.type);
}
switch (event->header.type) {
case PERF_RECORD_SAMPLE:
dump_sample(session, event, sample);
evsel = perf_evlist__id2evsel(session->evlist, sample->id);
if (evsel == NULL) {
++session->hists.stats.nr_unknown_id;
return -1;
......@@ -874,11 +891,11 @@ static void perf_session__warn_about_errors(const struct perf_session *session,
const struct perf_event_ops *ops)
{
if (ops->lost == perf_event__process_lost &&
session->hists.stats.total_lost != 0) {
ui__warning("Processed %" PRIu64 " events and LOST %" PRIu64
"!\n\nCheck IO/CPU overload!\n\n",
session->hists.stats.total_period,
session->hists.stats.total_lost);
session->hists.stats.nr_events[PERF_RECORD_LOST] != 0) {
ui__warning("Processed %d events and lost %d chunks!\n\n"
"Check IO/CPU overload!\n\n",
session->hists.stats.nr_events[0],
session->hists.stats.nr_events[PERF_RECORD_LOST]);
}
if (session->hists.stats.nr_unknown_events != 0) {
......
......@@ -19,7 +19,6 @@ struct perf_top {
u64 kernel_samples, us_samples;
u64 exact_samples;
u64 guest_us_samples, guest_kernel_samples;
u64 total_lost_warned;
int print_entries, count_filter, delay_secs;
int freq;
pid_t target_pid, target_tid;
......
......@@ -176,16 +176,29 @@ void ui_browser__handle_resize(struct ui_browser *browser)
ui_browser__refresh(browser);
}
int ui_browser__warning(struct ui_browser *browser, const char *format, ...)
int ui_browser__warning(struct ui_browser *browser, int timeout,
const char *format, ...)
{
va_list args;
int key;
char *text;
int key = 0, err;
va_start(args, format);
while ((key = __ui__warning("Warning!", format, args)) == K_RESIZE)
ui_browser__handle_resize(browser);
err = vasprintf(&text, format, args);
va_end(args);
if (err < 0) {
va_start(args, format);
ui_helpline__vpush(format, args);
va_end(args);
} else {
while ((key == ui__question_window("Warning!", text,
"Press any key...",
timeout)) == K_RESIZE)
ui_browser__handle_resize(browser);
free(text);
}
return key;
}
......
......@@ -45,7 +45,8 @@ int ui_browser__run(struct ui_browser *browser, int delay_secs);
void ui_browser__update_nr_entries(struct ui_browser *browser, u32 nr_entries);
void ui_browser__handle_resize(struct ui_browser *browser);
int ui_browser__warning(struct ui_browser *browser, const char *format, ...);
int ui_browser__warning(struct ui_browser *browser, int timeout,
const char *format, ...);
int ui_browser__help_window(struct ui_browser *browser, const char *text);
bool ui_browser__dialog_yesno(struct ui_browser *browser, const char *text);
......
......@@ -295,6 +295,15 @@ static void hist_browser__set_folding(struct hist_browser *self, bool unfold)
ui_browser__reset_index(&self->b);
}
static void ui_browser__warn_lost_events(struct ui_browser *browser)
{
ui_browser__warning(browser, 4,
"Events are being lost, check IO/CPU overload!\n\n"
"You may want to run 'perf' using a RT scheduler policy:\n\n"
" perf top -r 80\n\n"
"Or reduce the sampling frequency.");
}
static int hist_browser__run(struct hist_browser *self, const char *ev_name,
void(*timer)(void *arg), void *arg, int delay_secs)
{
......@@ -318,8 +327,15 @@ static int hist_browser__run(struct hist_browser *self, const char *ev_name,
case K_TIMER:
timer(arg);
ui_browser__update_nr_entries(&self->b, self->hists->nr_entries);
hists__browser_title(self->hists, title, sizeof(title),
ev_name);
if (self->hists->stats.nr_lost_warned !=
self->hists->stats.nr_events[PERF_RECORD_LOST]) {
self->hists->stats.nr_lost_warned =
self->hists->stats.nr_events[PERF_RECORD_LOST];
ui_browser__warn_lost_events(&self->b);
}
hists__browser_title(self->hists, title, sizeof(title), ev_name);
ui_browser__show_title(&self->b, title);
continue;
case 'D': { /* Debug */
......@@ -883,7 +899,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
goto out_free_stack;
case 'a':
if (!browser->has_symbols) {
ui_browser__warning(&browser->b,
ui_browser__warning(&browser->b, delay_secs * 2,
"Annotation is only available for symbolic views, "
"include \"sym\" in --sort to use it.");
continue;
......@@ -1061,6 +1077,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
struct perf_evsel_menu {
struct ui_browser b;
struct perf_evsel *selection;
bool lost_events, lost_events_warned;
};
static void perf_evsel_menu__write(struct ui_browser *browser,
......@@ -1073,14 +1090,29 @@ static void perf_evsel_menu__write(struct ui_browser *browser,
unsigned long nr_events = evsel->hists.stats.nr_events[PERF_RECORD_SAMPLE];
const char *ev_name = event_name(evsel);
char bf[256], unit;
const char *warn = " ";
size_t printed;
ui_browser__set_color(browser, current_entry ? HE_COLORSET_SELECTED :
HE_COLORSET_NORMAL);
nr_events = convert_unit(nr_events, &unit);
snprintf(bf, sizeof(bf), "%lu%c%s%s", nr_events,
unit, unit == ' ' ? "" : " ", ev_name);
slsmg_write_nstring(bf, browser->width);
printed = snprintf(bf, sizeof(bf), "%lu%c%s%s", nr_events,
unit, unit == ' ' ? "" : " ", ev_name);
slsmg_printf("%s", bf);
nr_events = evsel->hists.stats.nr_events[PERF_RECORD_LOST];
if (nr_events != 0) {
menu->lost_events = true;
if (!current_entry)
ui_browser__set_color(browser, HE_COLORSET_TOP);
nr_events = convert_unit(nr_events, &unit);
snprintf(bf, sizeof(bf), ": %ld%c%schunks LOST!", nr_events,
unit, unit == ' ' ? "" : " ");
warn = bf;
}
slsmg_write_nstring(warn, browser->width - printed);
if (current_entry)
menu->selection = evsel;
......@@ -1105,6 +1137,11 @@ static int perf_evsel_menu__run(struct perf_evsel_menu *menu,
switch (key) {
case K_TIMER:
timer(arg);
if (!menu->lost_events_warned && menu->lost_events) {
ui_browser__warn_lost_events(&menu->b);
menu->lost_events_warned = true;
}
continue;
case K_RIGHT:
case K_ENTER:
......
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