Re: [PATCH v4 1/2] perf parse: Refactor struct perf_evsel_config_term

Mathieu Poirier
2020-01-08T17:58:45Z

On Wed, 8 Jan 2020 at 07:20, Leo Yan <leo.yan@linaro.org> wrote:
>
> The struct perf_evsel_config_term::val is a union which contains
> multiple variables for corresponding types. This leads the union to
> be complex and also causes complex code logic.
>
> This patch refactors the structure to use two general variables in the
> 'val' union: one is 'num' for unsigned 64-bit integer and another is
> 'str' for string variable. This can simplify the data structure and
> the related code, this also can benefit for possibly extension.
>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
> ---
> tools/perf/arch/arm/util/cs-etm.c | 2 +-
> tools/perf/builtin-top.c | 2 +-
> tools/perf/util/auxtrace.c | 2 +-
> tools/perf/util/evsel.c | 24 +++++++-------
> tools/perf/util/evsel_config.h | 17 ++--------
> tools/perf/util/parse-events.c | 55 ++++++++++++++++++-------------
> 6 files changed, 49 insertions(+), 53 deletions(-)
>
> diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
> index ede040cf82ad..2898cfdf8fe1 100644
> --- a/tools/perf/arch/arm/util/cs-etm.c
> +++ b/tools/perf/arch/arm/util/cs-etm.c
> @@ -226,7 +226,7 @@ static int cs_etm_set_sink_attr(struct perf_pmu *pmu,
> if (term->type != PERF_EVSEL__CONFIG_TERM_DRV_CFG)
> continue;
>
> - sink = term->val.drv_cfg;
> + sink = term->val.str;
> snprintf(path, PATH_MAX, "sinks/%s", sink);
>
> ret = perf_pmu__scan_file(pmu, path, "%x", &hash);
> diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
> index 795e353de095..459be44ca2ff 100644
> --- a/tools/perf/builtin-top.c
> +++ b/tools/perf/builtin-top.c
> @@ -947,7 +947,7 @@ static int perf_top__overwrite_check(struct perf_top *top)
> config_terms = &evsel->config_terms;
> list_for_each_entry(term, config_terms, list) {
> if (term->type == PERF_EVSEL__CONFIG_TERM_OVERWRITE)
> - set = term->val.overwrite ? 1 : 0;
> + set = term->val.num ? 1 : 0;
> }
>
> /* no term for current and previous event (likely) */
> diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
> index eb087e7df6f4..a5c945aadfa7 100644
> --- a/tools/perf/util/auxtrace.c
> +++ b/tools/perf/util/auxtrace.c
> @@ -772,7 +772,7 @@ int auxtrace_parse_sample_options(struct auxtrace_record *itr,
> term = perf_evsel__get_config_term(evsel, AUX_SAMPLE_SIZE);
> if (term) {
> has_aux_sample_size = true;
> - evsel->core.attr.aux_sample_size = term->val.aux_sample_size;
> + evsel->core.attr.aux_sample_size = term->val.num;
> /* If possible, group with the AUX event */
> if (aux_evsel && evsel->core.attr.aux_sample_size)
> perf_evlist__regroup(evlist, aux_evsel, evsel);
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index a69e64236120..5f27f6b7ed94 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -789,43 +789,43 @@ static void apply_config_terms(struct evsel *evsel,
> switch (term->type) {
> case PERF_EVSEL__CONFIG_TERM_PERIOD:
> if (!(term->weak && opts->user_interval != ULLONG_MAX)) {
> - attr->sample_period = term->val.period;
> + attr->sample_period = term->val.num;
> attr->freq = 0;
> perf_evsel__reset_sample_bit(evsel, PERIOD);
> }
> break;
> case PERF_EVSEL__CONFIG_TERM_FREQ:
> if (!(term->weak && opts->user_freq != UINT_MAX)) {
> - attr->sample_freq = term->val.freq;
> + attr->sample_freq = term->val.num;
> attr->freq = 1;
> perf_evsel__set_sample_bit(evsel, PERIOD);
> }
> break;
> case PERF_EVSEL__CONFIG_TERM_TIME:
> - if (term->val.time)
> + if (term->val.num)
> perf_evsel__set_sample_bit(evsel, TIME);
> else
> perf_evsel__reset_sample_bit(evsel, TIME);
> break;
> case PERF_EVSEL__CONFIG_TERM_CALLGRAPH:
> - callgraph_buf = term->val.callgraph;
> + callgraph_buf = term->val.str;
> break;
> case PERF_EVSEL__CONFIG_TERM_BRANCH:
> - if (term->val.branch && strcmp(term->val.branch, "no")) {
> + if (term->val.str && strcmp(term->val.str, "no")) {
> perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
> - parse_branch_str(term->val.branch,
> + parse_branch_str(term->val.str,
> &attr->branch_sample_type);
> } else
> perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
> break;
> case PERF_EVSEL__CONFIG_TERM_STACK_USER:
> - dump_size = term->val.stack_user;
> + dump_size = term->val.num;
> break;
> case PERF_EVSEL__CONFIG_TERM_MAX_STACK:
> - max_stack = term->val.max_stack;
> + max_stack = term->val.num;
> break;
> case PERF_EVSEL__CONFIG_TERM_MAX_EVENTS:
> - evsel->max_events = term->val.max_events;
> + evsel->max_events = term->val.num;
> break;
> case PERF_EVSEL__CONFIG_TERM_INHERIT:
> /*
> @@ -834,17 +834,17 @@ static void apply_config_terms(struct evsel *evsel,
> * inherit using config terms, override global
> * opt->no_inherit setting.
> */
> - attr->inherit = term->val.inherit ? 1 : 0;
> + attr->inherit = term->val.num ? 1 : 0;
> break;
> case PERF_EVSEL__CONFIG_TERM_OVERWRITE:
> - attr->write_backward = term->val.overwrite ? 1 : 0;
> + attr->write_backward = term->val.num ? 1 : 0;
> break;
> case PERF_EVSEL__CONFIG_TERM_DRV_CFG:
> break;
> case PERF_EVSEL__CONFIG_TERM_PERCORE:
> break;
> case PERF_EVSEL__CONFIG_TERM_AUX_OUTPUT:
> - attr->aux_output = term->val.aux_output ? 1 : 0;
> + attr->aux_output = term->val.num ? 1 : 0;
> break;
> case PERF_EVSEL__CONFIG_TERM_AUX_SAMPLE_SIZE:
> /* Already applied by auxtrace */
> diff --git a/tools/perf/util/evsel_config.h b/tools/perf/util/evsel_config.h
> index 1f8d2fe0b66e..4e5b3ebf09cf 100644
> --- a/tools/perf/util/evsel_config.h
> +++ b/tools/perf/util/evsel_config.h
> @@ -33,21 +33,8 @@ struct perf_evsel_config_term {
> struct list_head list;
> enum evsel_term_type type;
> union {
> - u64 period;
> - u64 freq;
> - bool time;
> - char *callgraph;
> - char *drv_cfg;
> - u64 stack_user;
> - int max_stack;
> - bool inherit;
> - bool overwrite;
> - char *branch;
> - unsigned long max_events;
> - bool percore;
> - bool aux_output;
> - u32 aux_sample_size;
> - u64 cfg_chg;
> + u64 num;
> + char *str;

That is a lot more than just dealing with the "char *" members. Given
the pervasiveness of the changes I would have been happy to leave
other members alone for the time being. I will let Jiri make the
final call but if we are to proceed this way I think we should have a
member per type to avoid casting issues.

Thanks,
Mathieu

> } val;
> bool weak;
> };
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index ed7c008b9c8b..caf38518762f 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -1219,8 +1219,7 @@ static int config_attr(struct perf_event_attr *attr,
> static int get_config_terms(struct list_head *head_config,
> struct list_head *head_terms __maybe_unused)
> {
> -#define ADD_CONFIG_TERM(__type, __name, __val) \
> -do { \
> +#define ADD_CONFIG_TERM(__type) \
> struct perf_evsel_config_term *__t; \
> \
> __t = zalloc(sizeof(*__t)); \
> @@ -1229,9 +1228,19 @@ do { \
> \
> INIT_LIST_HEAD(&__t->list); \
> __t->type = PERF_EVSEL__CONFIG_TERM_ ## __type; \
> - __t->val.__name = __val; \
> __t->weak = term->weak; \
> - list_add_tail(&__t->list, head_terms); \
> + list_add_tail(&__t->list, head_terms)
> +
> +#define ADD_CONFIG_TERM_VAL(__type, __val) \
> +do { \
> + ADD_CONFIG_TERM(__type); \
> + __t->val.num = __val; \
> +} while (0)
> +
> +#define ADD_CONFIG_TERM_STR(__type, __val) \
> +do { \
> + ADD_CONFIG_TERM(__type); \
> + __t->val.str = __val; \
> } while (0)
>
> struct parse_events_term *term;
> @@ -1239,53 +1248,53 @@ do { \
> list_for_each_entry(term, head_config, list) {
> switch (term->type_term) {
> case PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD:
> - ADD_CONFIG_TERM(PERIOD, period, term->val.num);
> + ADD_CONFIG_TERM_VAL(PERIOD, term->val.num);
> break;
> case PARSE_EVENTS__TERM_TYPE_SAMPLE_FREQ:
> - ADD_CONFIG_TERM(FREQ, freq, term->val.num);
> + ADD_CONFIG_TERM_VAL(FREQ, term->val.num);
> break;
> case PARSE_EVENTS__TERM_TYPE_TIME:
> - ADD_CONFIG_TERM(TIME, time, term->val.num);
> + ADD_CONFIG_TERM_VAL(TIME, term->val.num);
> break;
> case PARSE_EVENTS__TERM_TYPE_CALLGRAPH:
> - ADD_CONFIG_TERM(CALLGRAPH, callgraph, term->val.str);
> + ADD_CONFIG_TERM_STR(CALLGRAPH, term->val.str);
> break;
> case PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE:
> - ADD_CONFIG_TERM(BRANCH, branch, term->val.str);
> + ADD_CONFIG_TERM_STR(BRANCH, term->val.str);
> break;
> case PARSE_EVENTS__TERM_TYPE_STACKSIZE:
> - ADD_CONFIG_TERM(STACK_USER, stack_user, term->val.num);
> + ADD_CONFIG_TERM_VAL(STACK_USER, term->val.num);
> break;
> case PARSE_EVENTS__TERM_TYPE_INHERIT:
> - ADD_CONFIG_TERM(INHERIT, inherit, term->val.num ? 1 : 0);
> + ADD_CONFIG_TERM_VAL(INHERIT, term->val.num ? 1 : 0);
> break;
> case PARSE_EVENTS__TERM_TYPE_NOINHERIT:
> - ADD_CONFIG_TERM(INHERIT, inherit, term->val.num ? 0 : 1);
> + ADD_CONFIG_TERM_VAL(INHERIT, term->val.num ? 0 : 1);
> break;
> case PARSE_EVENTS__TERM_TYPE_MAX_STACK:
> - ADD_CONFIG_TERM(MAX_STACK, max_stack, term->val.num);
> + ADD_CONFIG_TERM_VAL(MAX_STACK, term->val.num);
> break;
> case PARSE_EVENTS__TERM_TYPE_MAX_EVENTS:
> - ADD_CONFIG_TERM(MAX_EVENTS, max_events, term->val.num);
> + ADD_CONFIG_TERM_VAL(MAX_EVENTS, term->val.num);
> break;
> case PARSE_EVENTS__TERM_TYPE_OVERWRITE:
> - ADD_CONFIG_TERM(OVERWRITE, overwrite, term->val.num ? 1 : 0);
> + ADD_CONFIG_TERM_VAL(OVERWRITE, term->val.num ? 1 : 0);
> break;
> case PARSE_EVENTS__TERM_TYPE_NOOVERWRITE:
> - ADD_CONFIG_TERM(OVERWRITE, overwrite, term->val.num ? 0 : 1);
> + ADD_CONFIG_TERM_VAL(OVERWRITE, term->val.num ? 0 : 1);
> break;
> case PARSE_EVENTS__TERM_TYPE_DRV_CFG:
> - ADD_CONFIG_TERM(DRV_CFG, drv_cfg, term->val.str);
> + ADD_CONFIG_TERM_STR(DRV_CFG, term->val.str);
> break;
> case PARSE_EVENTS__TERM_TYPE_PERCORE:
> - ADD_CONFIG_TERM(PERCORE, percore,
> - term->val.num ? true : false);
> + ADD_CONFIG_TERM_VAL(PERCORE,
> + term->val.num ? true : false);
> break;
> case PARSE_EVENTS__TERM_TYPE_AUX_OUTPUT:
> - ADD_CONFIG_TERM(AUX_OUTPUT, aux_output, term->val.num ? 1 : 0);
> + ADD_CONFIG_TERM_VAL(AUX_OUTPUT, term->val.num ? 1 : 0);
> break;
> case PARSE_EVENTS__TERM_TYPE_AUX_SAMPLE_SIZE:
> - ADD_CONFIG_TERM(AUX_SAMPLE_SIZE, aux_sample_size, term->val.num);
> + ADD_CONFIG_TERM_VAL(AUX_SAMPLE_SIZE, term->val.num);
> break;
> default:
> break;
> @@ -1322,7 +1331,7 @@ static int get_config_chgs(struct perf_pmu *pmu, struct list_head *head_config,
> }
>
> if (bits)
> - ADD_CONFIG_TERM(CFG_CHG, cfg_chg, bits);
> + ADD_CONFIG_TERM_VAL(CFG_CHG, bits);
>
> #undef ADD_CONFIG_TERM
> return 0;
> @@ -1387,7 +1396,7 @@ static bool config_term_percore(struct list_head *config_terms)
>
> list_for_each_entry(term, config_terms, list) {
> if (term->type == PERF_EVSEL__CONFIG_TERM_PERCORE)
> - return term->val.percore;
> + return term->val.num;
> }
>
> return false;
> --
> 2.17.1
>