Re: [PATCH v4 6/8] perf/tools: Enhance JSON/metric infrastructure to handle "?"

Arnaldo Carvalho de Melo
2020-03-10T18:35:04Z

Em Mon, Mar 09, 2020 at 11:55:50AM +0530, Kajol Jain escreveu:
> Patch enhances current metric infrastructure to handle "?" in the metric
> expression. The "?" can be use for parameters whose value not known while
> creating metric events and which can be replace later at runtime to
> the proper value. It also add flexibility to create multiple events out
> of single metric event added in json file.
>
> Patch adds function 'arch_get_runtimeparam' which is a arch specific
> function, returns the count of metric events need to be created.
> By default it return 1.
>
> One loop is added in function 'metricgroup__add_metric', which create
> multiple events at run time depend on return value of
> 'arch_get_runtimeparam' and merge that event in 'group_list'.
>
> This infrastructure needed for hv_24x7 socket/chip level events.
> "hv_24x7" chip level events needs specific chip-id to which the
> data is requested. Function 'arch_get_runtimeparam' implemented
> in header.c which extract number of sockets from sysfs file
> "sockets" under "/sys/devices/hv_24x7/interface/".
>
> Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
> ---
> tools/perf/arch/powerpc/util/header.c | 22 +++++
> tools/perf/util/expr.h | 1 +
> tools/perf/util/expr.l | 19 +++-
> tools/perf/util/metricgroup.c | 124 ++++++++++++++++++++------
> tools/perf/util/metricgroup.h | 1 +
> tools/perf/util/stat-shadow.c | 8 ++
> 6 files changed, 148 insertions(+), 27 deletions(-)
>
> diff --git a/tools/perf/arch/powerpc/util/header.c b/tools/perf/arch/powerpc/util/header.c
> index 3b4cdfc5efd6..036f6b2ce202 100644
> --- a/tools/perf/arch/powerpc/util/header.c
> +++ b/tools/perf/arch/powerpc/util/header.c
> @@ -7,6 +7,11 @@
> #include <string.h>
> #include <linux/stringify.h>
> #include "header.h"
> +#include "metricgroup.h"
> +#include "evlist.h"
> +#include <dirent.h>
> +#include "pmu.h"
> +#include <api/fs/fs.h>
>
> #define mfspr(rn) ({unsigned long rval; \
> asm volatile("mfspr %0," __stringify(rn) \
> @@ -16,6 +21,8 @@
> #define PVR_VER(pvr) (((pvr) >> 16) & 0xFFFF) /* Version field */
> #define PVR_REV(pvr) (((pvr) >> 0) & 0xFFFF) /* Revison field */
>
> +#define SOCKETS_INFO_FILE_PATH "/devices/hv_24x7/interface/"
> +
> int
> get_cpuid(char *buffer, size_t sz)
> {
> @@ -44,3 +51,18 @@ get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
>
> return bufp;
> }
> +
> +int arch_get_runtimeparam(void)
> +{
> + int count;
> + char path[PATH_MAX];
> + char filename[] = "sockets";
> +
> + snprintf(path, PATH_MAX,
> + SOCKETS_INFO_FILE_PATH "%s", filename);
> +
> + if (sysfs__read_ull(path, (unsigned long long *)&count) < 0)
> + return 1;
> + else
> + return count;

Why this cast dance? We have sysfs__read_int(path, &count).

Also this is more compact:

return sysfs__read_int(path, &count) < 0 ? 1 : count;

> +}
> diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
> index 9377538f4097..d17664e628db 100644
> --- a/tools/perf/util/expr.h
> +++ b/tools/perf/util/expr.h
> @@ -15,6 +15,7 @@ struct parse_ctx {
> struct parse_id ids[MAX_PARSE_ID];
> };
>
> +int expr__runtimeparam;
> void expr__ctx_init(struct parse_ctx *ctx);
> void expr__add_id(struct parse_ctx *ctx, const char *id, double val);
> int expr__parse(double *final_val, struct parse_ctx *ctx, const char *expr);
> diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
> index 1928f2a3dddc..ec4b00671f67 100644
> --- a/tools/perf/util/expr.l
> +++ b/tools/perf/util/expr.l
> @@ -45,6 +45,21 @@ static char *normalize(char *str)
> *dst++ = '/';
> else if (*str == '\\')
> *dst++ = *++str;
> + else if (*str == '?') {
> +
> + int size = snprintf(NULL, 0, "%d", expr__runtimeparam);

TIL that C99 allows for a NULL str to format and return the number of
bytes it would write if the string was large enough... wonders never
cease :-)

> + char * paramval = (char *)malloc(size);

No need for the cast, malloc returns void *, or has that changed? 8-)
and please no space before the variable name.

Humm this is all complicated, why not use asprintf and have something
like:

> + int i = 0;
> +
> + if(!paramval)
> + *dst++ = '0';
> + else {
> + sprintf(paramval, "%d", expr__runtimeparam);
> + while(i < size)
> + *dst++ = paramval[i++];
> + free(paramval);
> + }

char *paramval;
int size = asprintf(&paramval, "%d", expr__runtimeparam);

if (size < 0)
*dst++ = '0';
else {
while (i < size)
*dst++ = paramval[i++];
free(paramval);
}

> + }
> else
> *dst++ = *str;
> str++;
> @@ -72,8 +87,8 @@ number [0-9]+
>
> sch [-,=]
> spec \\{sch}
> -sym [0-9a-zA-Z_\.:@]+
> -symbol {spec}*{sym}*{spec}*{sym}*
> +sym [0-9a-zA-Z_\.:@?]+
> +symbol {spec}*{sym}*{spec}*{sym}*{spec}*{sym}
>
> %%
> {
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index c3a8c701609a..11eeeb929b91 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -474,6 +474,98 @@ static bool metricgroup__has_constraint(struct pmu_event *pe)
> return false;
> }
>
> +int __weak arch_get_runtimeparam(void)
> +{
> + return 1;
> +}
> +
> +static int metricgroup__add_metric_runtime_param(struct strbuf *events,
> + struct list_head *group_list, struct pmu_event *pe)
> +{
> + int i, count;
> + int ret = -EINVAL;
> +
> + count = arch_get_runtimeparam();
> +
> + /* This loop is added to create multiple
> + * events depend on count value and add
> + * those events to group_list.
> + */
> +
> + for (i = 0; i < count; i++) {
> + const char **ids;
> + int idnum;
> + struct egroup *eg;
> + char value[PATH_MAX];
> +
> + expr__runtimeparam = i;
> +
> + if (expr__find_other(pe->metric_expr,
> + NULL, &ids, &idnum) < 0)
> + return ret;
> +
> + if (events->len > 0)
> + strbuf_addf(events, ",");
> +
> + if (metricgroup__has_constraint(pe))
> + metricgroup__add_metric_non_group(events, ids, idnum);
> + else
> + metricgroup__add_metric_weak_group(events, ids, idnum);
> +
> + eg = malloc(sizeof(struct egroup));

Shorter form that works even if you change that type:

+ eg = malloc(sizeof(*eg));

> + if (!eg) {
> + ret = -ENOMEM;
> + return ret;
> + }
> + sprintf(value, "%s%c%d", pe->metric_name, '_', i);
> + eg->ids = ids;
> + eg->idnum = idnum;
> + eg->metric_name = strdup(value);

Please check strdup() return just like you checked the malloc(sizeof(struct egroup)).

> + eg->metric_expr = pe->metric_expr;
> + eg->metric_unit = pe->unit;
> + list_add_tail(&eg->nd, group_list);
> + ret = 0;
> +
> + if (ret != 0)
> + break;
> + }
> + return ret;
> +}
> +static int metricgroup__add_metric_param(struct strbuf *events,
> + struct list_head *group_list, struct pmu_event *pe)
> +{
> +
> + const char **ids;
> + int idnum;
> + struct egroup *eg;
> + int ret = -EINVAL;
> +
> + if (expr__find_other(pe->metric_expr,
> + NULL, &ids, &idnum) < 0)

Why break the above in two lines?

> + return ret;
> + if (events->len > 0)
> + strbuf_addf(events, ",");
> +
> + if (metricgroup__has_constraint(pe))
> + metricgroup__add_metric_non_group(events, ids, idnum);
> + else
> + metricgroup__add_metric_weak_group(events, ids, idnum);
> +
> + eg = malloc(sizeof(struct egroup));

Ditto

> + if (!eg)
> + ret = -ENOMEM;
> +
> + eg->ids = ids;
> + eg->idnum = idnum;
> + eg->metric_name = pe->metric_name;
> + eg->metric_expr = pe->metric_expr;
> + eg->metric_unit = pe->unit;
> + list_add_tail(&eg->nd, group_list);
> + ret = 0;
> +
> + return ret;
> +}
> +
> static int metricgroup__add_metric(const char *metric, struct strbuf *events,
> struct list_head *group_list)
> {
> @@ -493,35 +585,17 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
> continue;
> if (match_metric(pe->metric_group, metric) ||
> match_metric(pe->metric_name, metric)) {
> - const char **ids;
> - int idnum;
> - struct egroup *eg;
>
> pr_debug("metric expr %s for %s\n", pe->metric_expr, pe->metric_name);
>
> - if (expr__find_other(pe->metric_expr,
> - NULL, &ids, &idnum) < 0)
> - continue;
> - if (events->len > 0)
> - strbuf_addf(events, ",");
> -
> - if (metricgroup__has_constraint(pe))
> - metricgroup__add_metric_non_group(events, ids, idnum);
> + if (strstr(pe->metric_expr, "?"))
> + ret = metricgroup__add_metric_runtime_param(events,
> + group_list, pe);
> else
> - metricgroup__add_metric_weak_group(events, ids, idnum);
> -
> - eg = malloc(sizeof(struct egroup));

*eg
> - if (!eg) {
> - ret = -ENOMEM;
> - break;
> - }
> - eg->ids = ids;
> - eg->idnum = idnum;
> - eg->metric_name = pe->metric_name;
> - eg->metric_expr = pe->metric_expr;
> - eg->metric_unit = pe->unit;
> - list_add_tail(&eg->nd, group_list);
> - ret = 0;
> + ret = metricgroup__add_metric_param(events,
> + group_list, pe);
> + if (ret == -EINVAL)
> + continue;
> }
> }
> return ret;
> diff --git a/tools/perf/util/metricgroup.h b/tools/perf/util/metricgroup.h
> index 475c7f912864..81224ba1270d 100644
> --- a/tools/perf/util/metricgroup.h
> +++ b/tools/perf/util/metricgroup.h
> @@ -34,4 +34,5 @@ int metricgroup__parse_groups(const struct option *opt,
> void metricgroup__print(bool metrics, bool groups, char *filter,
> bool raw, bool details);
> bool metricgroup__has_metric(const char *metric);
> +int arch_get_runtimeparam(void);
> #endif
> diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
> index 0fd713d3674f..92c4c9abbaa0 100644
> --- a/tools/perf/util/stat-shadow.c
> +++ b/tools/perf/util/stat-shadow.c
> @@ -777,6 +777,14 @@ static void generic_metric(struct perf_stat_config *config,
> }
>
> if (!metric_events[i]) {
> +
> + if (strstr(metric_expr, "?")) {
> + char *tmp = strrchr(metric_name, '_');
> +

So at this point a metric name is guaranteed to have a _?

> + tmp++;
> + expr__runtimeparam = strtol(tmp, &tmp, 10);
> + }
> +
> if (expr__parse(&ratio, &pctx, metric_expr) == 0) {
> char *unit;
> char metric_bf[64];
> --
> 2.18.1
>

--

- Arnaldo