perf pmu: Remove perf_pmu__hybrid_mounted

perf_pmu__hybrid_mounted is used to detect whether cpu_core or
cpu_atom is mounted with a non-empty cpus file by
pmu_lookup. Discussion [1] showed the empty cpus file check to be
redundant and so pmu_lookup needn't have a call to
perf_pmu__hybrid_mounted.

Checking hybrid_mounted in pmu_is_uncore is redundant as the next
cpumask read will fail returning false.

Reduce the scope of perf_pmu__find_hybrid_pmu by making it static.

[1] https://lore.kernel.org/lkml/[email protected]/

Reviewed-by: Kan Liang <[email protected]>
Signed-off-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ali Saidi <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Dmitrii Dolgov <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jing Zhang <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Kang Minchul <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Ming Wang <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Sandipan Das <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Xing Zhengjun <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

3 files changed, 2 insertions, 29 deletions

diff --git a/tools/perf/util/pmu-hybrid.c b/tools/perf/util/pmu-hybrid.c
index bc4cb0738c35..7fe943dd3217 100644
--- a/tools/perf/util/pmu-hybrid.c
+++ b/tools/perf/util/pmu-hybrid.c
@@ -18,20 +18,7 @@
 
 LIST_HEAD(perf_pmu__hybrid_pmus);
 
-bool perf_pmu__hybrid_mounted(const char *name)
-{
-	int cpu;
-	char pmu_name[PATH_MAX];
-	struct perf_pmu pmu = {.name = pmu_name};
-
-	if (strncmp(name, "cpu_", 4))
-		return false;
-
-	strlcpy(pmu_name, name, sizeof(pmu_name));
-	return perf_pmu__scan_file(&pmu, "cpus", "%u", &cpu) > 0;
-}
-
-struct perf_pmu *perf_pmu__find_hybrid_pmu(const char *name)
+static struct perf_pmu *perf_pmu__find_hybrid_pmu(const char *name)
 {
 	struct perf_pmu *pmu;
 
diff --git a/tools/perf/util/pmu-hybrid.h b/tools/perf/util/pmu-hybrid.h
index 206b94931531..8dbcae935020 100644
--- a/tools/perf/util/pmu-hybrid.h
+++ b/tools/perf/util/pmu-hybrid.h
@@ -13,9 +13,6 @@ extern struct list_head perf_pmu__hybrid_pmus;
 #define perf_pmu__for_each_hybrid_pmu(pmu)	\
 	list_for_each_entry(pmu, &perf_pmu__hybrid_pmus, hybrid_list)
 
-bool perf_pmu__hybrid_mounted(const char *name);
-
-struct perf_pmu *perf_pmu__find_hybrid_pmu(const char *name);
 bool perf_pmu__is_hybrid(const char *name);
 
 static inline int perf_pmu__hybrid_pmu_num(void)
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index cd94abe7a87a..83c7eeb8abea 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -617,9 +617,6 @@ static bool pmu_is_uncore(int dirfd, const char *name)
 {
 	int fd;
 
-	if (perf_pmu__hybrid_mounted(name))
-		return false;
-
 	fd = perf_pmu__pathname_fd(dirfd, name, "cpumask", O_PATH);
 	if (fd < 0)
 		return false;
@@ -907,16 +904,9 @@ static struct perf_pmu *pmu_lookup(int dirfd, const char *lookup_name)
 	LIST_HEAD(aliases);
 	__u32 type;
 	char *name = pmu_find_real_name(lookup_name);
-	bool is_hybrid = perf_pmu__hybrid_mounted(name);
 	char *alias_name;
 
 	/*
-	 * Check pmu name for hybrid and the pmu may be invalid in sysfs
-	 */
-	if (!strncmp(name, "cpu_", 4) && !is_hybrid)
-		return NULL;
-
-	/*
 	 * The pmu data we store & need consists of the pmu
 	 * type value and format definitions. Load both right
 	 * now.
@@ -936,7 +926,6 @@ static struct perf_pmu *pmu_lookup(int dirfd, const char *lookup_name)
 
 	pmu->cpus = pmu_cpumask(dirfd, name);
 	pmu->name = strdup(name);
-
 	if (!pmu->name)
 		goto err;
 
@@ -967,7 +956,7 @@ static struct perf_pmu *pmu_lookup(int dirfd, const char *lookup_name)
 	list_splice(&aliases, &pmu->aliases);
 	list_add_tail(&pmu->list, &pmus);
 
-	if (is_hybrid)
+	if (!strcmp(name, "cpu_core") || !strcmp(name, "cpu_atom"))
 		list_add_tail(&pmu->hybrid_list, &perf_pmu__hybrid_pmus);
 	else
 		INIT_LIST_HEAD(&pmu->hybrid_list);