Re: [PATCH 1/1] perf evsel: Introduce evsel__name_is() method to check if the evsel name is equal to a given string

Liang, Kan
2023-04-20T21:16:26Z

On 2023-04-20 3:28 p.m., Arnaldo Carvalho de Melo wrote:
> Em Thu, Apr 20, 2023 at 04:10:30PM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Thu, Apr 20, 2023 at 03:57:55PM -0300, Arnaldo Carvalho de Melo escreveu:
>>> This makes the logic a bit clear by avoiding the !strcmp() pattern and
>>> also a way to intercept the pointer if we need to do extra validation on
>>> it or to do lazy setting of evsel->name via evsel__name(evsel).
>>
>> + this, looking if there are others...
>
> Somehow the first message didn't go thru, so below is the combined
> patch, this is an effort to avoid accessing evsel->name directly as the
> preferred way to get an evsel name is evsel__name(), so looking for
> direct access and providing accessors that avoid that.

One more

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 2260e27adf44..3a960a3f6962 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -467,7 +467,7 @@ static int evsel__strcmp(struct evsel *pos, char
*evsel_name)
return 0;
if (evsel__is_dummy_event(pos))
return 1;
- return strcmp(pos->name, evsel_name);
+ return !evsel__name_is(pos, evsel_name);
}

static int evlist__is_enabled(struct evlist *evlist)

>
> - Arnaldo
>
> From e60455d6a4e35ba0c376966443294586a1adc3ec Mon Sep 17 00:00:00 2001
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> Date: Thu, 20 Apr 2023 15:54:11 -0300
> Subject: [PATCH 1/1] perf evsel: Introduce evsel__name_is() method to check if
> the evsel name is equal to a given string
>
> This makes the logic a bit clear by avoiding the !strcmp() pattern and
> also a way to intercept the pointer if we need to do extra validation on
> it or to do lazy setting of evsel->name via evsel__name(evsel).
>
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Ian Rogers <irogers@google.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: "Liang, Kan" <kan.liang@linux.intel.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Link: https://lore.kernel.org/lkml/ZEGLM8VehJbS0gP2@kernel.org
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

With the above one,

Reviewed-by: Kan Liang <kan.liang@linux.intel.com>

Thanks,
Kan
> ---
> tools/perf/arch/arm64/util/kvm-stat.c | 4 ++--
> tools/perf/arch/powerpc/util/kvm-stat.c | 4 ++--
> tools/perf/arch/x86/util/kvm-stat.c | 8 ++++----
> tools/perf/builtin-kvm.c | 6 +++---
> tools/perf/builtin-stat.c | 2 +-
> tools/perf/tests/expand-cgroup.c | 2 +-
> tools/perf/tests/parse-events.c | 12 ++++++------
> tools/perf/tests/parse-metric.c | 2 +-
> tools/perf/tests/pmu-events.c | 2 +-
> tools/perf/util/evsel.c | 7 ++++++-
> tools/perf/util/evsel.h | 1 +
> 11 files changed, 28 insertions(+), 22 deletions(-)
>
> diff --git a/tools/perf/arch/arm64/util/kvm-stat.c b/tools/perf/arch/arm64/util/kvm-stat.c
> index 72ca9bb45804d109..6611aa21cba957d9 100644
> --- a/tools/perf/arch/arm64/util/kvm-stat.c
> +++ b/tools/perf/arch/arm64/util/kvm-stat.c
> @@ -44,14 +44,14 @@ static bool event_begin(struct evsel *evsel,
> struct perf_sample *sample __maybe_unused,
> struct event_key *key __maybe_unused)
> {
> - return !strcmp(evsel->name, kvm_entry_trace);
> + return evsel__name_is(evsel, kvm_entry_trace);
> }
>
> static bool event_end(struct evsel *evsel,
> struct perf_sample *sample,
> struct event_key *key)
> {
> - if (!strcmp(evsel->name, kvm_exit_trace)) {
> + if (evsel__name_is(evsel, kvm_exit_trace)) {
> event_get_key(evsel, sample, key);
> return true;
> }
> diff --git a/tools/perf/arch/powerpc/util/kvm-stat.c b/tools/perf/arch/powerpc/util/kvm-stat.c
> index d04a08c9fd19c58c..ea1220d66b6758b2 100644
> --- a/tools/perf/arch/powerpc/util/kvm-stat.c
> +++ b/tools/perf/arch/powerpc/util/kvm-stat.c
> @@ -60,13 +60,13 @@ static bool hcall_event_end(struct evsel *evsel,
> struct perf_sample *sample __maybe_unused,
> struct event_key *key __maybe_unused)
> {
> - return (!strcmp(evsel->name, kvm_events_tp[3]));
> + return (evsel__name_is(evsel, kvm_events_tp[3]));
> }
>
> static bool hcall_event_begin(struct evsel *evsel,
> struct perf_sample *sample, struct event_key *key)
> {
> - if (!strcmp(evsel->name, kvm_events_tp[2])) {
> + if (evsel__name_is(evsel, kvm_events_tp[2])) {
> hcall_event_get_key(evsel, sample, key);
> return true;
> }
> diff --git a/tools/perf/arch/x86/util/kvm-stat.c b/tools/perf/arch/x86/util/kvm-stat.c
> index ef513def03bac71c..424716518b755915 100644
> --- a/tools/perf/arch/x86/util/kvm-stat.c
> +++ b/tools/perf/arch/x86/util/kvm-stat.c
> @@ -46,7 +46,7 @@ static bool mmio_event_begin(struct evsel *evsel,
> return true;
>
> /* MMIO write begin event in kernel. */
> - if (!strcmp(evsel->name, "kvm:kvm_mmio") &&
> + if (evsel__name_is(evsel, "kvm:kvm_mmio") &&
> evsel__intval(evsel, sample, "type") == KVM_TRACE_MMIO_WRITE) {
> mmio_event_get_key(evsel, sample, key);
> return true;
> @@ -63,7 +63,7 @@ static bool mmio_event_end(struct evsel *evsel, struct perf_sample *sample,
> return true;
>
> /* MMIO read end event in kernel.*/
> - if (!strcmp(evsel->name, "kvm:kvm_mmio") &&
> + if (evsel__name_is(evsel, "kvm:kvm_mmio") &&
> evsel__intval(evsel, sample, "type") == KVM_TRACE_MMIO_READ) {
> mmio_event_get_key(evsel, sample, key);
> return true;
> @@ -101,7 +101,7 @@ static bool ioport_event_begin(struct evsel *evsel,
> struct perf_sample *sample,
> struct event_key *key)
> {
> - if (!strcmp(evsel->name, "kvm:kvm_pio")) {
> + if (evsel__name_is(evsel, "kvm:kvm_pio")) {
> ioport_event_get_key(evsel, sample, key);
> return true;
> }
> @@ -145,7 +145,7 @@ static bool msr_event_begin(struct evsel *evsel,
> struct perf_sample *sample,
> struct event_key *key)
> {
> - if (!strcmp(evsel->name, "kvm:kvm_msr")) {
> + if (evsel__name_is(evsel, "kvm:kvm_msr")) {
> msr_event_get_key(evsel, sample, key);
> return true;
> }
> diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
> index 747d19336340f28f..71165036e4cac89b 100644
> --- a/tools/perf/builtin-kvm.c
> +++ b/tools/perf/builtin-kvm.c
> @@ -625,7 +625,7 @@ void exit_event_get_key(struct evsel *evsel,
>
> bool kvm_exit_event(struct evsel *evsel)
> {
> - return !strcmp(evsel->name, kvm_exit_trace);
> + return evsel__name_is(evsel, kvm_exit_trace);
> }
>
> bool exit_event_begin(struct evsel *evsel,
> @@ -641,7 +641,7 @@ bool exit_event_begin(struct evsel *evsel,
>
> bool kvm_entry_event(struct evsel *evsel)
> {
> - return !strcmp(evsel->name, kvm_entry_trace);
> + return evsel__name_is(evsel, kvm_entry_trace);
> }
>
> bool exit_event_end(struct evsel *evsel,
> @@ -878,7 +878,7 @@ static bool is_child_event(struct perf_kvm_stat *kvm,
> return false;
>
> for (; child_ops->name; child_ops++) {
> - if (!strcmp(evsel->name, child_ops->name)) {
> + if (evsel__name_is(evsel, child_ops->name)) {
> child_ops->get_key(evsel, sample, key);
> return true;
> }
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index d3cbee7460fcc48e..efda63f6bf329b51 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -2170,7 +2170,7 @@ static void setup_system_wide(int forks)
>
> evlist__for_each_entry(evsel_list, counter) {
> if (!counter->core.requires_cpu &&
> - strcmp(counter->name, "duration_time")) {
> + !evsel__name_is(counter, "duration_time")) {
> return;
> }
> }
> diff --git a/tools/perf/tests/expand-cgroup.c b/tools/perf/tests/expand-cgroup.c
> index ec340880a848d907..9c1a1f18db750607 100644
> --- a/tools/perf/tests/expand-cgroup.c
> +++ b/tools/perf/tests/expand-cgroup.c
> @@ -61,7 +61,7 @@ static int test_expand_events(struct evlist *evlist,
>
> i = 0;
> evlist__for_each_entry(evlist, evsel) {
> - if (strcmp(evsel->name, ev_name[i % nr_events])) {
> + if (!evsel__name_is(evsel, ev_name[i % nr_events])) {
> pr_debug("event name doesn't match:\n");
> pr_debug(" evsel[%d]: %s\n expected: %s\n",
> i, evsel->name, ev_name[i % nr_events]);
> diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
> index 6eb1400443adddee..8068cfd89b84f723 100644
> --- a/tools/perf/tests/parse-events.c
> +++ b/tools/perf/tests/parse-events.c
> @@ -1401,7 +1401,7 @@ static int test__checkevent_config_symbol(struct evlist *evlist)
> {
> struct evsel *evsel = evlist__first(evlist);
>
> - TEST_ASSERT_VAL("wrong name setting", strcmp(evsel->name, "insn") == 0);
> + TEST_ASSERT_VAL("wrong name setting", evsel__name_is(evsel, "insn"));
> return TEST_OK;
> }
>
> @@ -1409,7 +1409,7 @@ static int test__checkevent_config_raw(struct evlist *evlist)
> {
> struct evsel *evsel = evlist__first(evlist);
>
> - TEST_ASSERT_VAL("wrong name setting", strcmp(evsel->name, "rawpmu") == 0);
> + TEST_ASSERT_VAL("wrong name setting", evsel__name_is(evsel, "rawpmu"));
> return TEST_OK;
> }
>
> @@ -1417,7 +1417,7 @@ static int test__checkevent_config_num(struct evlist *evlist)
> {
> struct evsel *evsel = evlist__first(evlist);
>
> - TEST_ASSERT_VAL("wrong name setting", strcmp(evsel->name, "numpmu") == 0);
> + TEST_ASSERT_VAL("wrong name setting", evsel__name_is(evsel, "numpmu"));
> return TEST_OK;
> }
>
> @@ -1425,7 +1425,7 @@ static int test__checkevent_config_cache(struct evlist *evlist)
> {
> struct evsel *evsel = evlist__first(evlist);
>
> - TEST_ASSERT_VAL("wrong name setting", strcmp(evsel->name, "cachepmu") == 0);
> + TEST_ASSERT_VAL("wrong name setting", evsel__name_is(evsel, "cachepmu"));
> return TEST_OK;
> }
>
> @@ -1438,7 +1438,7 @@ static int test__intel_pt(struct evlist *evlist)
> {
> struct evsel *evsel = evlist__first(evlist);
>
> - TEST_ASSERT_VAL("wrong name setting", strcmp(evsel->name, "intel_pt//u") == 0);
> + TEST_ASSERT_VAL("wrong name setting", evsel__name_is(evsel, "intel_pt//u"));
> return TEST_OK;
> }
>
> @@ -1446,7 +1446,7 @@ static int test__checkevent_complex_name(struct evlist *evlist)
> {
> struct evsel *evsel = evlist__first(evlist);
>
> - TEST_ASSERT_VAL("wrong complex name parsing", strcmp(evsel->name, "COMPLEX_CYCLES_NAME:orig=cycles,desc=chip-clock-ticks") == 0);
> + TEST_ASSERT_VAL("wrong complex name parsing", evsel__name_is(evsel, "COMPLEX_CYCLES_NAME:orig=cycles,desc=chip-clock-ticks"));
> return TEST_OK;
> }
>
> diff --git a/tools/perf/tests/parse-metric.c b/tools/perf/tests/parse-metric.c
> index c43b056f9fa395f4..1185b79e6274886e 100644
> --- a/tools/perf/tests/parse-metric.c
> +++ b/tools/perf/tests/parse-metric.c
> @@ -39,7 +39,7 @@ static void load_runtime_stat(struct evlist *evlist, struct value *vals)
> evlist__for_each_entry(evlist, evsel) {
> count = find_value(evsel->name, vals);
> evsel->stats->aggr->counts.val = count;
> - if (!strcmp(evsel->name, "duration_time"))
> + if (evsel__name_is(evsel, "duration_time"))
> update_stats(&walltime_nsecs_stats, count);
> }
> }
> diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
> index 7f8e864525271483..1dff863b9711cf6d 100644
> --- a/tools/perf/tests/pmu-events.c
> +++ b/tools/perf/tests/pmu-events.c
> @@ -866,7 +866,7 @@ static int test__parsing_callback(const struct pmu_metric *pm,
> evlist__alloc_aggr_stats(evlist, 1);
> evlist__for_each_entry(evlist, evsel) {
> evsel->stats->aggr->counts.val = k;
> - if (!strcmp(evsel->name, "duration_time"))
> + if (evsel__name_is(evsel, "duration_time"))
> update_stats(&walltime_nsecs_stats, k);
> k++;
> }
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index a85a987128aad281..81b854650160c2b0 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -821,6 +821,11 @@ const char *evsel__name(struct evsel *evsel)
> return "unknown";
> }
>
> +bool evsel__name_is(struct evsel *evsel, const char *name)
> +{
> + return !strcmp(evsel->name, name);
> +}
> +
> const char *evsel__group_pmu_name(const struct evsel *evsel)
> {
> const struct evsel *leader;
> @@ -1146,7 +1151,7 @@ static void evsel__set_default_freq_period(struct record_opts *opts,
>
> static bool evsel__is_offcpu_event(struct evsel *evsel)
> {
> - return evsel__is_bpf_output(evsel) && !strcmp(evsel->name, OFFCPU_EVENT);
> + return evsel__is_bpf_output(evsel) && evsel__name_is(evsel, OFFCPU_EVENT);
> }
>
> /*
> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> index 68072ec655ce9fff..1e5d640e4a9bd0f1 100644
> --- a/tools/perf/util/evsel.h
> +++ b/tools/perf/util/evsel.h
> @@ -282,6 +282,7 @@ int arch_evsel__hw_name(struct evsel *evsel, char *bf, size_t size);
>
> int __evsel__hw_cache_type_op_res_name(u8 type, u8 op, u8 result, char *bf, size_t size);
> const char *evsel__name(struct evsel *evsel);
> +bool evsel__name_is(struct evsel *evsel, const char *name);
> const char *evsel__group_pmu_name(const struct evsel *evsel);
> const char *evsel__metric_id(const struct evsel *evsel);
>