perf metric: Encode and use metric-id as qualifier

For a metric like IPC a group of events like {instructions,cycles}:W
would be formed.

If the events names were changed in parsing then the metric expression
parser would fail to find them.

This change makes the event encoding be something like:

  {instructions/metric-id=instructions/, cycles/metric-id=cycles/}

and then uses the evsel's stable metric-id value to locate the events.

This fixes the case that an event is restricted to user because of the
paranoia setting:

  $ echo 2 > /proc/sys/kernel/perf_event_paranoid
  $ perf stat -M IPC /bin/true
   Performance counter stats for '/bin/true':

             150,298      inst_retired.any:u        #      0.77 IPC
             187,095      cpu_clk_unhalted.thread:u

         0.002042731 seconds time elapsed

         0.000000000 seconds user
         0.002377000 seconds sys

Adding the metric-id as a qualifier has a complication in that
qualifiers will become embedded in qualifiers.

For example, msr/tsc/ could become msr/tsc,metric-id=msr/tsc// which
will fail parse-events.

To solve this problem the metric is encoded and decoded for the
metric-id with !<num> standing in for an encoded value.

Previously ! wasn't parsed.

With this msr/tsc/ becomes msr/tsc,metric-id=msr!3tsc!3/

The metric expression parser is changed so that @ isn't changed to /,
instead this is done when the ID is encoded for parse events.

metricgroup__add_metric_non_group() and metricgroup__add_metric_weak_group()
need to inject the metric-id qualifier, so to avoid repetition they are
merged into a single metricgroup__build_event_string with error codes
more rigorously checked.

stat-shadow's prepare_metric() uses the metric-id to match the metricgroup
code.

As "metric-id=..." is added to all events, it is adding during testing
with the fake PMU.

This complicates pmu_str_check code as PE_PMU_EVENT_FAKE won't match as
part of a configuration.

The testing fake PMU case is fixed so that if a known qualifier with an
! is parsed then it isn't reported as a fake PMU.

This is sufficient to pass all testing but it and the original mechanism
are somewhat brittle.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Antonov <alexander.antonov@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Kilroy <andrew.kilroy@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Changbin Du <changbin.du@intel.com>
Cc: Denys Zagorui <dzagorui@cisco.com>
Cc: Fabian Hemmer <copy@copy.sh>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joakim Zhang <qiangqing.zhang@nxp.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kees Kook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nicholas Fraser <nfraser@codeweavers.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: ShihCheng Tu <mrtoastcheng@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Wan Jiabing <wanjiabing@vivo.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20211015172132.1162559-17-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ian Rogers 2021-10-15 10:21:27 -07:00 committed by Arnaldo Carvalho de Melo
parent fb0811535e
commit ec5c5b3d2c
6 changed files with 240 additions and 79 deletions

View File

@ -129,9 +129,9 @@ int test__expr(struct test *t __maybe_unused, int subtest __maybe_unused)
expr__find_ids("EVENT1\\,param\\=?@ + EVENT2\\,param\\=?@",
NULL, ctx) == 0);
TEST_ASSERT_VAL("find ids", hashmap__size(ctx->ids) == 2);
TEST_ASSERT_VAL("find ids", hashmap__find(ctx->ids, "EVENT1,param=3/",
TEST_ASSERT_VAL("find ids", hashmap__find(ctx->ids, "EVENT1,param=3@",
(void **)&val_ptr));
TEST_ASSERT_VAL("find ids", hashmap__find(ctx->ids, "EVENT2,param=3/",
TEST_ASSERT_VAL("find ids", hashmap__find(ctx->ids, "EVENT2,param=3@",
(void **)&val_ptr));
/* Only EVENT1 or EVENT2 need be measured depending on the value of smt_on. */

View File

@ -761,6 +761,7 @@ static int check_parse_id(const char *id, struct parse_events_error *error,
{
struct evlist *evlist;
int ret;
char *dup, *cur;
/* Numbers are always valid. */
if (is_number(id))
@ -769,7 +770,17 @@ static int check_parse_id(const char *id, struct parse_events_error *error,
evlist = evlist__new();
if (!evlist)
return -ENOMEM;
ret = __parse_events(evlist, id, error, fake_pmu);
dup = strdup(id);
if (!dup)
return -ENOMEM;
for (cur = strchr(dup, '@') ; cur; cur = strchr(++cur, '@'))
*cur = '/';
ret = __parse_events(evlist, dup, error, fake_pmu);
free(dup);
evlist__delete(evlist);
return ret;
}

View File

@ -41,11 +41,9 @@ static char *normalize(char *str, int runtime)
char *dst = str;
while (*str) {
if (*str == '@')
*dst++ = '/';
else if (*str == '\\')
if (*str == '\\')
*dst++ = *++str;
else if (*str == '?') {
else if (*str == '?') {
char *paramval;
int i = 0;
int size = asprintf(&paramval, "%d", runtime);

View File

@ -212,13 +212,13 @@ static void metric__free(struct metric *m)
free(m);
}
static bool contains_event(struct evsel **metric_events, int num_events,
const char *event_name)
static bool contains_metric_id(struct evsel **metric_events, int num_events,
const char *metric_id)
{
int i;
for (i = 0; i < num_events; i++) {
if (!strcmp(metric_events[i]->name, event_name))
if (!strcmp(evsel__metric_id(metric_events[i]), metric_id))
return true;
}
return false;
@ -259,6 +259,7 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist,
{
struct evsel *ev, *current_leader = NULL;
struct expr_id_data *val_ptr;
const char *metric_id;
int i = 0, matched_events = 0, events_to_match;
int idnum = (int)hashmap__size(pctx->ids);
@ -300,10 +301,11 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist,
* different sibling groups aren't both added to
* metric_events.
*/
if (contains_event(metric_events, matched_events, ev->name))
metric_id = evsel__metric_id(ev);
if (contains_metric_id(metric_events, matched_events, metric_id))
continue;
/* Does this event belong to the parse context? */
if (hashmap__find(pctx->ids, ev->name, (void **)&val_ptr))
if (hashmap__find(pctx->ids, metric_id, (void **)&val_ptr))
metric_events[matched_events++] = ev;
if (matched_events == events_to_match)
@ -347,6 +349,7 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist,
* for each pmu. Set the metric leader of such events to be the
* event that appears in metric_events.
*/
metric_id = evsel__metric_id(ev);
evlist__for_each_entry_continue(perf_evlist, ev) {
/*
* If events are grouped then the search can terminate
@ -356,7 +359,7 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist,
ev->core.leader != metric_events[i]->core.leader &&
evsel_same_pmu_or_none(evsel__leader(ev), evsel__leader(metric_events[i])))
break;
if (!strcmp(metric_events[i]->name, ev->name)) {
if (!strcmp(evsel__metric_id(metric_events[i]), metric_id)) {
set_bit(ev->core.idx, evlist_used);
ev->metric_leader = metric_events[i];
}
@ -724,50 +727,191 @@ void metricgroup__print(bool metrics, bool metricgroups, char *filter,
strlist__delete(metriclist);
}
static void metricgroup__add_metric_weak_group(struct strbuf *events,
struct expr_parse_ctx *ctx)
static const char *code_characters = ",-=@";
static int encode_metric_id(struct strbuf *sb, const char *x)
{
char *c;
int ret = 0;
for (; *x; x++) {
c = strchr(code_characters, *x);
if (c) {
ret = strbuf_addch(sb, '!');
if (ret)
break;
ret = strbuf_addch(sb, '0' + (c - code_characters));
if (ret)
break;
} else {
ret = strbuf_addch(sb, *x);
if (ret)
break;
}
}
return ret;
}
static int decode_metric_id(struct strbuf *sb, const char *x)
{
const char *orig = x;
size_t i;
char c;
int ret;
for (; *x; x++) {
c = *x;
if (*x == '!') {
x++;
i = *x - '0';
if (i > strlen(code_characters)) {
pr_err("Bad metric-id encoding in: '%s'", orig);
return -1;
}
c = code_characters[i];
}
ret = strbuf_addch(sb, c);
if (ret)
return ret;
}
return 0;
}
static int decode_all_metric_ids(struct evlist *perf_evlist)
{
struct evsel *ev;
struct strbuf sb = STRBUF_INIT;
char *cur;
int ret = 0;
evlist__for_each_entry(perf_evlist, ev) {
if (!ev->metric_id)
continue;
ret = strbuf_setlen(&sb, 0);
if (ret)
break;
ret = decode_metric_id(&sb, ev->metric_id);
if (ret)
break;
free((char *)ev->metric_id);
ev->metric_id = strdup(sb.buf);
if (!ev->metric_id) {
ret = -ENOMEM;
break;
}
/*
* If the name is just the parsed event, use the metric-id to
* give a more friendly display version.
*/
if (strstr(ev->name, "metric-id=")) {
free(ev->name);
for (cur = strchr(sb.buf, '@') ; cur; cur = strchr(++cur, '@'))
*cur = '/';
ev->name = strdup(sb.buf);
if (!ev->name) {
ret = -ENOMEM;
break;
}
}
}
strbuf_release(&sb);
return ret;
}
static int metricgroup__build_event_string(struct strbuf *events,
const struct expr_parse_ctx *ctx,
bool has_constraint)
{
struct hashmap_entry *cur;
size_t bkt;
bool no_group = true, has_duration = false;
int ret = 0;
#define RETURN_IF_NON_ZERO(x) do { if (x) return x; } while (0)
hashmap__for_each_entry(ctx->ids, cur, bkt) {
pr_debug("found event %s\n", (const char *)cur->key);
const char *sep, *rsep, *id = cur->key;
pr_debug("found event %s\n", id);
/*
* Duration time maps to a software event and can make
* groups not count. Always use it outside a
* group.
*/
if (!strcmp(cur->key, "duration_time")) {
if (!strcmp(id, "duration_time")) {
has_duration = true;
continue;
}
strbuf_addf(events, "%s%s",
no_group ? "{" : ",",
(const char *)cur->key);
no_group = false;
}
if (!no_group) {
strbuf_addf(events, "}:W");
if (has_duration)
strbuf_addf(events, ",duration_time");
} else if (has_duration)
strbuf_addf(events, "duration_time");
}
/* Separate events with commas and open the group if necessary. */
if (no_group) {
if (!has_constraint) {
ret = strbuf_addch(events, '{');
RETURN_IF_NON_ZERO(ret);
}
static void metricgroup__add_metric_non_group(struct strbuf *events,
struct expr_parse_ctx *ctx)
{
struct hashmap_entry *cur;
size_t bkt;
bool first = true;
no_group = false;
} else {
ret = strbuf_addch(events, ',');
RETURN_IF_NON_ZERO(ret);
}
/*
* Encode the ID as an event string. Add a qualifier for
* metric_id that is the original name except with characters
* that parse-events can't parse replaced. For example,
* 'msr@tsc@' gets added as msr/tsc,metric-id=msr!3tsc!3/
*/
sep = strchr(id, '@');
if (sep != NULL) {
ret = strbuf_add(events, id, sep - id);
RETURN_IF_NON_ZERO(ret);
ret = strbuf_addch(events, '/');
RETURN_IF_NON_ZERO(ret);
rsep = strrchr(sep, '@');
ret = strbuf_add(events, sep + 1, rsep - sep - 1);
RETURN_IF_NON_ZERO(ret);
ret = strbuf_addstr(events, ",metric-id=");
RETURN_IF_NON_ZERO(ret);
sep = rsep;
} else {
sep = strchr(id, ':');
if (sep != NULL) {
ret = strbuf_add(events, id, sep - id);
RETURN_IF_NON_ZERO(ret);
} else {
ret = strbuf_addstr(events, id);
RETURN_IF_NON_ZERO(ret);
}
ret = strbuf_addstr(events, "/metric-id=");
RETURN_IF_NON_ZERO(ret);
}
ret = encode_metric_id(events, id);
RETURN_IF_NON_ZERO(ret);
ret = strbuf_addstr(events, "/");
RETURN_IF_NON_ZERO(ret);
hashmap__for_each_entry(ctx->ids, cur, bkt) {
if (!first)
strbuf_addf(events, ",");
strbuf_addf(events, "%s", (const char *)cur->key);
first = false;
if (sep != NULL) {
ret = strbuf_addstr(events, sep + 1);
RETURN_IF_NON_ZERO(ret);
}
}
if (has_duration) {
if (no_group) {
/* Strange case of a metric of just duration_time. */
ret = strbuf_addf(events, "duration_time");
} else if (!has_constraint)
ret = strbuf_addf(events, "}:W,duration_time");
else
ret = strbuf_addf(events, ",duration_time");
} else if (!no_group && !has_constraint)
ret = strbuf_addf(events, "}:W");
return ret;
#undef RETURN_IF_NON_ZERO
}
int __weak arch_get_runtimeparam(const struct pmu_event *pe __maybe_unused)
@ -1134,16 +1278,17 @@ static int metricgroup__add_metric(const char *metric_name, bool metric_no_group
list_sort(NULL, &list, metric_list_cmp);
list_for_each_entry(m, &list, nd) {
if (events->len > 0)
strbuf_addf(events, ",");
if (m->has_constraint) {
metricgroup__add_metric_non_group(events,
m->pctx);
} else {
metricgroup__add_metric_weak_group(events,
m->pctx);
if (events->len > 0) {
ret = strbuf_addf(events, ",");
if (ret)
break;
}
ret = metricgroup__build_event_string(events,
m->pctx,
m->has_constraint);
if (ret)
break;
}
out:
@ -1180,30 +1325,40 @@ static int metricgroup__add_metric_list(const char *list, bool metric_no_group,
const struct pmu_events_map *map)
{
char *llist, *nlist, *p;
int ret = -EINVAL;
int ret, count = 0;
nlist = strdup(list);
if (!nlist)
return -ENOMEM;
llist = nlist;
strbuf_init(events, 100);
strbuf_addf(events, "%s", "");
ret = strbuf_init(events, 100);
if (ret)
return ret;
while ((p = strsep(&llist, ",")) != NULL) {
ret = metricgroup__add_metric(p, metric_no_group, events,
metric_list, map);
if (ret == -EINVAL) {
fprintf(stderr, "Cannot find metric or group `%s'\n",
p);
if (ret == -EINVAL)
fprintf(stderr, "Cannot find metric or group `%s'\n", p);
if (ret)
break;
}
count++;
}
free(nlist);
if (!ret)
if (!ret) {
/*
* Warn about nmi_watchdog if any parsed metrics had the
* NO_NMI_WATCHDOG constraint.
*/
metricgroup___watchdog_constraint_hint(NULL, true);
/* No metrics. */
if (count == 0)
return -EINVAL;
}
return ret;
}
@ -1243,6 +1398,10 @@ static int parse_groups(struct evlist *perf_evlist, const char *str,
parse_events_print_error(&parse_error, extra_events.buf);
goto out;
}
ret = decode_all_metric_ids(perf_evlist);
if (ret)
goto out;
ret = metricgroup__setup_events(&metric_list, metric_no_merge,
perf_evlist, metric_events);
out:

View File

@ -138,18 +138,23 @@ static int pmu_str_check(yyscan_t scanner, struct parse_events_state *parse_stat
yylval->str = strdup(text);
if (parse_state->fake_pmu)
return PE_PMU_EVENT_FAKE;
/*
* If we're not testing then parse check determines the PMU event type
* which if it isn't a PMU returns PE_NAME. When testing the result of
* parse check can't be trusted so we return PE_PMU_EVENT_FAKE unless
* an '!' is present in which case the text can't be a PMU name.
*/
switch (perf_pmu__parse_check(text)) {
case PMU_EVENT_SYMBOL_PREFIX:
return PE_PMU_EVENT_PRE;
case PMU_EVENT_SYMBOL_SUFFIX:
return PE_PMU_EVENT_SUF;
case PMU_EVENT_SYMBOL:
return PE_KERNEL_PMU_EVENT;
return parse_state->fake_pmu
? PE_PMU_EVENT_FAKE : PE_KERNEL_PMU_EVENT;
default:
return PE_NAME;
return parse_state->fake_pmu && !strchr(text,'!')
? PE_PMU_EVENT_FAKE : PE_NAME;
}
}
@ -204,7 +209,7 @@ bpf_source [^,{}]+\.c[a-zA-Z0-9._]*
num_dec [0-9]+
num_hex 0x[a-fA-F0-9]+
num_raw_hex [a-fA-F0-9]+
name [a-zA-Z_*?\[\]][a-zA-Z0-9_*?.\[\]]*
name [a-zA-Z_*?\[\]][a-zA-Z0-9_*?.\[\]!]*
name_tag [\'][a-zA-Z_*?\[\]][a-zA-Z0-9_*?\-,\.\[\]:=]*[\']
name_minus [a-zA-Z_*?][a-zA-Z0-9\-_*?.:]*
drv_cfg_term [a-zA-Z0-9_\.]+(=[a-zA-Z0-9_*?\.:]+)?

View File

@ -821,7 +821,7 @@ static int prepare_metric(struct evsel **metric_events,
struct runtime_stat *st)
{
double scale;
char *n, *pn;
char *n;
int i, j, ret;
for (i = 0; metric_events[i]; i++) {
@ -844,23 +844,11 @@ static int prepare_metric(struct evsel **metric_events,
if (v->metric_other)
metric_total = v->metric_total;
}
n = strdup(metric_events[i]->name);
n = strdup(evsel__metric_id(metric_events[i]));
if (!n)
return -ENOMEM;
/*
* This display code with --no-merge adds [cpu] postfixes.
* These are not supported by the parser. Remove everything
* after the space.
*/
pn = strchr(n, ' ');
if (pn)
*pn = 0;
if (metric_total)
expr__add_id_val(pctx, n, metric_total);
else
expr__add_id_val(pctx, n, avg_stats(stats)*scale);
expr__add_id_val(pctx, n, metric_total ? : avg_stats(stats) * scale);
}
for (j = 0; metric_refs && metric_refs[j].metric_name; j++) {