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Date: Tue,  9 Apr 2024 18:13:12 -0700
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Subject: [PATCH v2 1/2] perf pmus: Sort/merge/aggregate PMUs like mrvl_ddr_pmu
From: Ian Rogers <irogers@google.com>
To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, 
	Arnaldo Carvalho de Melo <acme@kernel.org>, Namhyung Kim <namhyung@kernel.org>, 
	Mark Rutland <mark.rutland@arm.com>, 
	Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@kernel.org>, 
	Ian Rogers <irogers@google.com>, Adrian Hunter <adrian.hunter@intel.com>, 
	Athira Jajeev <atrajeev@linux.vnet.ibm.com>, James Clark <james.clark@arm.com>, 
	Kan Liang <kan.liang@linux.intel.com>, Ravi Bangoria <ravi.bangoria@amd.com>, 
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, 
	Bharat Bhushan <bbhushan2@marvell.com>, Bhaskara Budiredla <bbudiredla@marvell.com>, 
	Will Deacon <will@kernel.org>, Stephane Eranian <eranian@google.com>
Content-Type: text/plain; charset="UTF-8"

The mrvl_ddr_pmu is uncore and has a hexadecimal address suffix while
the previous PMU sorting/merging code assumes uncore PMU names start
with uncore_ and have a decimal suffix. Because of the previous
assumption it isn't possible to wildcard the mrvl_ddr_pmu.

Modify pmu_name_len_no_suffix but also remove the suffix number out
argument, this is because we don't know if a suffix number of say 10
is in hexadecimal or decimal. As the only use of the suffix number is
in comparisons, it is safe there to compare the values as hexadecimal.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/pmu.c  |  2 +-
 tools/perf/util/pmus.c | 51 ++++++++++++++++++++++--------------------
 tools/perf/util/pmus.h |  7 +++++-
 3 files changed, 34 insertions(+), 26 deletions(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index f39cbbc1a7ec..b0cca5841f90 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1657,7 +1657,7 @@ static char *format_alias(char *buf, int len, const struct perf_pmu *pmu,
 {
 	struct parse_events_term *term;
 	int pmu_name_len = skip_duplicate_pmus
-		? pmu_name_len_no_suffix(pmu->name, /*num=*/NULL)
+		? pmu_name_len_no_suffix(pmu->name)
 		: (int)strlen(pmu->name);
 	int used = snprintf(buf, len, "%.*s/%s", pmu_name_len, pmu->name, alias->name);
 
diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 16505071d362..b4ddcd0ade26 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -39,31 +39,44 @@ static bool read_sysfs_all_pmus;
 
 static void pmu_read_sysfs(bool core_only);
 
-int pmu_name_len_no_suffix(const char *str, unsigned long *num)
+int pmu_name_len_no_suffix(const char *str)
 {
 	int orig_len, len;
 
 	orig_len = len = strlen(str);
 
-	/* Non-uncore PMUs have their full length, for example, i915. */
-	if (!strstarts(str, "uncore_"))
-		return len;
-
 	/*
 	 * Count trailing digits and '_', if '_{num}' suffix isn't present use
 	 * the full length.
 	 */
-	while (len > 0 && isdigit(str[len - 1]))
+	while (len > 0 && isxdigit(str[len - 1]))
 		len--;
 
-	if (len > 0 && len != orig_len && str[len - 1] == '_') {
-		if (num)
-			*num = strtoul(&str[len], NULL, 10);
+	if (len > 0 && len != orig_len && str[len - 1] == '_')
 		return len - 1;
-	}
+
 	return orig_len;
 }
 
+int pmu_name_cmp(const char *lhs_pmu_name, const char *rhs_pmu_name)
+{
+	unsigned long lhs_num = 0, rhs_num = 0;
+	int lhs_pmu_name_len = pmu_name_len_no_suffix(lhs_pmu_name);
+	int rhs_pmu_name_len = pmu_name_len_no_suffix(rhs_pmu_name);
+	int ret = strncmp(lhs_pmu_name, rhs_pmu_name,
+			lhs_pmu_name_len < rhs_pmu_name_len ? lhs_pmu_name_len : rhs_pmu_name_len);
+
+	if (lhs_pmu_name_len != rhs_pmu_name_len || ret != 0 || lhs_pmu_name_len == 0)
+		return ret;
+
+	if (lhs_pmu_name_len + 1 < (int)strlen(lhs_pmu_name))
+		lhs_num = strtoul(&lhs_pmu_name[lhs_pmu_name_len + 1], NULL, 16);
+	if (rhs_pmu_name_len + 1 < (int)strlen(rhs_pmu_name))
+		rhs_num = strtoul(&rhs_pmu_name[rhs_pmu_name_len + 1], NULL, 16);
+
+	return lhs_num < rhs_num ? -1 : (lhs_num > rhs_num ? 1 : 0);
+}
+
 void perf_pmus__destroy(void)
 {
 	struct perf_pmu *pmu, *tmp;
@@ -164,20 +177,10 @@ static struct perf_pmu *perf_pmu__find2(int dirfd, const char *name)
 static int pmus_cmp(void *priv __maybe_unused,
 		    const struct list_head *lhs, const struct list_head *rhs)
 {
-	unsigned long lhs_num = 0, rhs_num = 0;
 	struct perf_pmu *lhs_pmu = container_of(lhs, struct perf_pmu, list);
 	struct perf_pmu *rhs_pmu = container_of(rhs, struct perf_pmu, list);
-	const char *lhs_pmu_name = lhs_pmu->name ?: "";
-	const char *rhs_pmu_name = rhs_pmu->name ?: "";
-	int lhs_pmu_name_len = pmu_name_len_no_suffix(lhs_pmu_name, &lhs_num);
-	int rhs_pmu_name_len = pmu_name_len_no_suffix(rhs_pmu_name, &rhs_num);
-	int ret = strncmp(lhs_pmu_name, rhs_pmu_name,
-			lhs_pmu_name_len < rhs_pmu_name_len ? lhs_pmu_name_len : rhs_pmu_name_len);
 
-	if (lhs_pmu_name_len != rhs_pmu_name_len || ret != 0 || lhs_pmu_name_len == 0)
-		return ret;
-
-	return lhs_num < rhs_num ? -1 : (lhs_num > rhs_num ? 1 : 0);
+	return pmu_name_cmp(lhs_pmu->name ?: "", rhs_pmu->name ?: "");
 }
 
 /* Add all pmus in sysfs to pmu list: */
@@ -297,11 +300,11 @@ static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
 		pmu_read_sysfs(/*core_only=*/false);
 		pmu = list_prepare_entry(pmu, &core_pmus, list);
 	} else
-		last_pmu_name_len = pmu_name_len_no_suffix(pmu->name ?: "", NULL);
+		last_pmu_name_len = pmu_name_len_no_suffix(pmu->name ?: "");
 
 	if (use_core_pmus) {
 		list_for_each_entry_continue(pmu, &core_pmus, list) {
-			int pmu_name_len = pmu_name_len_no_suffix(pmu->name ?: "", /*num=*/NULL);
+			int pmu_name_len = pmu_name_len_no_suffix(pmu->name ?: "");
 
 			if (last_pmu_name_len == pmu_name_len &&
 			    !strncmp(last_pmu_name, pmu->name ?: "", pmu_name_len))
@@ -313,7 +316,7 @@ static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
 		pmu = list_prepare_entry(pmu, &other_pmus, list);
 	}
 	list_for_each_entry_continue(pmu, &other_pmus, list) {
-		int pmu_name_len = pmu_name_len_no_suffix(pmu->name ?: "", /*num=*/NULL);
+		int pmu_name_len = pmu_name_len_no_suffix(pmu->name ?: "");
 
 		if (last_pmu_name_len == pmu_name_len &&
 		    !strncmp(last_pmu_name, pmu->name ?: "", pmu_name_len))
diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
index 94d2a08d894b..624c2d53fc30 100644
--- a/tools/perf/util/pmus.h
+++ b/tools/perf/util/pmus.h
@@ -2,10 +2,15 @@
 #ifndef __PMUS_H
 #define __PMUS_H
 
+#include <stdbool.h>
+#include <linux/list.h>
+
 struct perf_pmu;
 struct print_callbacks;
 
-int pmu_name_len_no_suffix(const char *str, unsigned long *num);
+int pmu_name_len_no_suffix(const char *str);
+/* Exposed for testing only. */
+int pmu_name_cmp(const char *lhs_pmu_name, const char *rhs_pmu_name);
 
 void perf_pmus__destroy(void);
 
-- 
2.44.0.478.gd926399ef9-goog