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perf pmu: Merge JSON events with sysfs at load time
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Rather than load all sysfs events then parsing all JSON events and
merging with ones that already exist. When a sysfs event is loaded, look
for a corresponding JSON event and merge immediately.

To simplify the logic, early exit the perf_pmu__new_alias function if an
alias is attempted to be added twice - as merging has already been
explicitly handled.

Fix the copying of terms to a merged alias and some ENOMEM paths.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230824041330.266337-12-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Ian Rogers authored and Arnaldo Carvalho de Melo committed Aug 24, 2023
1 parent f26d22f commit f63a536
Showing 1 changed file with 88 additions and 89 deletions.
177 changes: 88 additions & 89 deletions tools/perf/util/pmu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -377,38 +377,6 @@ static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias,
return 0;
}

static void perf_pmu_assign_str(char *name, const char *field, char **old_str,
char **new_str)
{
if (!*old_str)
goto set_new;

if (*new_str) { /* Have new string, check with old */
if (strcasecmp(*old_str, *new_str))
pr_debug("alias %s differs in field '%s'\n",
name, field);
zfree(old_str);
} else /* Nothing new --> keep old string */
return;
set_new:
*old_str = *new_str;
*new_str = NULL;
}

static void perf_pmu_update_alias(struct perf_pmu_alias *old,
struct perf_pmu_alias *newalias)
{
perf_pmu_assign_str(old->name, "desc", &old->desc, &newalias->desc);
perf_pmu_assign_str(old->name, "long_desc", &old->long_desc,
&newalias->long_desc);
perf_pmu_assign_str(old->name, "topic", &old->topic, &newalias->topic);
perf_pmu_assign_str(old->name, "value", &old->str, &newalias->str);
old->scale = newalias->scale;
old->per_pkg = newalias->per_pkg;
old->snapshot = newalias->snapshot;
memcpy(old->unit, newalias->unit, sizeof(old->unit));
}

/* Delete an alias entry. */
static void perf_pmu_free_alias(struct perf_pmu_alias *newalias)
{
Expand All @@ -432,26 +400,58 @@ static void perf_pmu__del_aliases(struct perf_pmu *pmu)
}
}

/* Merge an alias, search in alias list. If this name is already
* present merge both of them to combine all information.
*/
static bool perf_pmu_merge_alias(struct perf_pmu *pmu,
struct perf_pmu_alias *newalias)
static struct perf_pmu_alias *perf_pmu__find_alias(const struct perf_pmu *pmu, const char *name)
{
struct perf_pmu_alias *a;
struct perf_pmu_alias *alias;

list_for_each_entry(a, &pmu->aliases, list) {
if (!strcasecmp(newalias->name, a->name)) {
if (newalias->pmu_name && a->pmu_name &&
!strcasecmp(newalias->pmu_name, a->pmu_name)) {
continue;
}
perf_pmu_update_alias(a, newalias);
perf_pmu_free_alias(newalias);
return true;
}
list_for_each_entry(alias, &pmu->aliases, list) {
if (!strcasecmp(alias->name, name))
return alias;
}
return false;
return NULL;
}

static bool assign_str(const char *name, const char *field, char **old_str,
const char *new_str)
{
if (!*old_str && new_str) {
*old_str = strdup(new_str);
return true;
}

if (!new_str || !strcasecmp(*old_str, new_str))
return false; /* Nothing to update. */

pr_debug("alias %s differs in field '%s' ('%s' != '%s')\n",
name, field, *old_str, new_str);
zfree(old_str);
*old_str = strdup(new_str);
return true;
}

static int update_alias(const struct pmu_event *pe,
const struct pmu_events_table *table __maybe_unused,
void *vdata)
{
struct perf_pmu_alias *alias = vdata;
int ret = 0;

assign_str(pe->name, "desc", &alias->desc, pe->desc);
assign_str(pe->name, "long_desc", &alias->long_desc, pe->long_desc);
assign_str(pe->name, "topic", &alias->topic, pe->topic);
alias->per_pkg = pe->perpkg;
if (assign_str(pe->name, "value", &alias->str, pe->event)) {
parse_events_terms__purge(&alias->terms);
ret = parse_events_terms(&alias->terms, pe->event, /*input=*/NULL);
}
if (!ret && pe->unit) {
char *unit;

ret = perf_pmu__convert_scale(pe->unit, &unit, &alias->scale);
if (!ret)
snprintf(alias->unit, sizeof(alias->unit), "%s", unit);
}
return ret;
}

static int perf_pmu__new_alias(struct perf_pmu *pmu, int dirfd, const char *name,
Expand All @@ -465,6 +465,11 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, int dirfd, const char *name
const char *long_desc = NULL, *topic = NULL, *unit = NULL, *pmu_name = NULL;
bool deprecated = false, perpkg = false;

if (perf_pmu__find_alias(pmu, name)) {
/* Alias was already created/loaded. */
return 0;
}

if (pe) {
long_desc = pe->long_desc;
topic = pe->topic;
Expand Down Expand Up @@ -492,27 +497,6 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, int dirfd, const char *name
return ret;
}

/* Scan event and remove leading zeroes, spaces, newlines, some
* platforms have terms specified as
* event=0x0091 (read from files ../<PMU>/events/<FILE>
* and terms specified as event=0x91 (read from JSON files).
*
* Rebuild string to make alias->str member comparable.
*/
memset(newval, 0, sizeof(newval));
ret = 0;
list_for_each_entry(term, &alias->terms, list) {
if (ret)
ret += scnprintf(newval + ret, sizeof(newval) - ret,
",");
if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM)
ret += scnprintf(newval + ret, sizeof(newval) - ret,
"%s=%#x", term->config, term->val.num);
else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
ret += scnprintf(newval + ret, sizeof(newval) - ret,
"%s=%s", term->config, term->val.str);
}

alias->name = strdup(name);
if (dirfd >= 0) {
/*
Expand All @@ -528,17 +512,43 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, int dirfd, const char *name
alias->long_desc = long_desc ? strdup(long_desc) :
desc ? strdup(desc) : NULL;
alias->topic = topic ? strdup(topic) : NULL;
alias->pmu_name = pmu_name ? strdup(pmu_name) : NULL;
if (unit) {
if (perf_pmu__convert_scale(unit, (char **)&unit, &alias->scale) < 0)
if (perf_pmu__convert_scale(unit, (char **)&unit, &alias->scale) < 0) {
perf_pmu_free_alias(alias);
return -1;
}
snprintf(alias->unit, sizeof(alias->unit), "%s", unit);
}
alias->str = strdup(newval);
alias->pmu_name = pmu_name ? strdup(pmu_name) : NULL;
if (!pe) {
/* Update an event from sysfs with json data. */
const struct pmu_events_table *table = perf_pmu__find_events_table(pmu);

if (!perf_pmu_merge_alias(pmu, alias))
list_add_tail(&alias->list, &pmu->aliases);
if (table)
pmu_events_table__find_event(table, pmu, name, update_alias, alias);
}

/* Scan event and remove leading zeroes, spaces, newlines, some
* platforms have terms specified as
* event=0x0091 (read from files ../<PMU>/events/<FILE>
* and terms specified as event=0x91 (read from JSON files).
*
* Rebuild string to make alias->str member comparable.
*/
ret = 0;
list_for_each_entry(term, &alias->terms, list) {
if (ret)
ret += scnprintf(newval + ret, sizeof(newval) - ret,
",");
if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM)
ret += scnprintf(newval + ret, sizeof(newval) - ret,
"%s=%#x", term->config, term->val.num);
else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
ret += scnprintf(newval + ret, sizeof(newval) - ret,
"%s=%s", term->config, term->val.str);
}
alias->str = strdup(newval);
list_add_tail(&alias->list, &pmu->aliases);
return 0;
}

Expand Down Expand Up @@ -944,6 +954,9 @@ struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char
INIT_LIST_HEAD(&pmu->format);
INIT_LIST_HEAD(&pmu->aliases);
INIT_LIST_HEAD(&pmu->caps);
pmu->name = strdup(name);
if (!pmu->name)
goto err;
/*
* The pmu data we store & need consists of the pmu
* type value and format definitions. Load both right
Expand All @@ -962,9 +975,6 @@ struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char
}
pmu->is_core = is_pmu_core(name);
pmu->cpus = pmu_cpumask(dirfd, name, pmu->is_core);
pmu->name = strdup(name);
if (!pmu->name)
goto err;

/* Read type, and ensure that type value is successfully assigned (return 1) */
if (perf_pmu__scan_file_at(pmu, dirfd, "type", "%u", &type) != 1)
Expand Down Expand Up @@ -1357,17 +1367,6 @@ int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
return perf_pmu__config_terms(pmu, attr, head_terms, zero, err);
}

static struct perf_pmu_alias *perf_pmu__find_alias(const struct perf_pmu *pmu, const char *str)
{
struct perf_pmu_alias *alias;

list_for_each_entry(alias, &pmu->aliases, list) {
if (!strcasecmp(alias->name, str))
return alias;
}
return NULL;
}

static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
struct parse_events_term *term)
{
Expand Down

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