libperf cpumap: Remove perf_cpu_map__read()

JIRA: https://issues.redhat.com/browse/RHEL-73893

upstream
========
commit e9ca57d
Author: Ian Rogers <irogers@google.com>
Date: Thu Dec 5 20:40:34 2024 -0800

description
===========
Function is no longer used and duplicates the parsing logic from
perf_cpu_map__new().

Remove to allow simplification.

    Reviewed-by: Leo Yan <leo.yan@arm.com>
    Signed-off-by: Ian Rogers <irogers@google.com>
    Cc: Adrian Hunter <adrian.hunter@intel.com>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Ben Gainey <ben.gainey@arm.com>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: James Clark <james.clark@linaro.org>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: Kan Liang <kan.liang@linux.intel.com>
    Cc: Kyle Meyer <kyle.meyer@hpe.com>
    Cc: Mark Rutland <mark.rutland@arm.com>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Link: https://lore.kernel.org/r/20241206044035.1062032-8-irogers@google.com
[ Applied manually to cope with "libperf cpumap: Refactor perf_cpu_map__merge()" ]
    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: Michael Petlan <mpetlan@redhat.com>

Author: rfmvh

tools/lib/perf/Documentation/libperf.txt

@@ -39,7 +39,6 @@ SYNOPSIS
 
   struct perf_cpu_map *perf_cpu_map__new_any_cpu(void);
   struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list);
-  struct perf_cpu_map *perf_cpu_map__read(FILE *file);
   struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map);
   struct perf_cpu_map *perf_cpu_map__merge(struct perf_cpu_map *orig,
                                            struct perf_cpu_map *other);

tools/lib/perf/cpumap.c

@@ -161,62 +161,6 @@ static struct perf_cpu_map *cpu_map__trim_new(int nr_cpus, const struct perf_cpu
 	return cpus;
 }
 
-struct perf_cpu_map *perf_cpu_map__read(FILE *file)
-{
-	struct perf_cpu_map *cpus = NULL;
-	int nr_cpus = 0;
-	struct perf_cpu *tmp_cpus = NULL, *tmp;
-	int max_entries = 0;
-	int n, cpu, prev;
-	char sep;
-
-	sep = 0;
-	prev = -1;
-	for (;;) {
-		n = fscanf(file, "%u%c", &cpu, &sep);
-		if (n <= 0)
-			break;
-		if (prev >= 0) {
-			int new_max = nr_cpus + cpu - prev - 1;
-
-			WARN_ONCE(new_max >= MAX_NR_CPUS, "Perf can support %d CPUs. "
-							  "Consider raising MAX_NR_CPUS\n", MAX_NR_CPUS);
-
-			if (new_max >= max_entries) {
-				max_entries = new_max + MAX_NR_CPUS / 2;
-				tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
-				if (tmp == NULL)
-					goto out_free_tmp;
-				tmp_cpus = tmp;
-			}
-
-			while (++prev < cpu)
-				tmp_cpus[nr_cpus++].cpu = prev;
-		}
-		if (nr_cpus == max_entries) {
-			max_entries += MAX_NR_CPUS;
-			tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu));
-			if (tmp == NULL)
-				goto out_free_tmp;
-			tmp_cpus = tmp;
-		}
-
-		tmp_cpus[nr_cpus++].cpu = cpu;
-		if (n == 2 && sep == '-')
-			prev = cpu;
-		else
-			prev = -1;
-		if (n == 1 || sep == '\n')
-			break;
-	}
-
-	if (nr_cpus > 0)
-		cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
-out_free_tmp:
-	free(tmp_cpus);
-	return cpus;
-}
-
 struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list)
 {
 	struct perf_cpu_map *cpus = NULL;

tools/lib/perf/include/perf/cpumap.h

@@ -3,7 +3,6 @@
 #define __LIBPERF_CPUMAP_H
 
 #include <perf/core.h>
-#include <stdio.h>
 #include <stdbool.h>
 
 /** A wrapper around a CPU to avoid confusion with the perf_cpu_map's map's indices. */
@@ -37,7 +36,6 @@ LIBPERF_API struct perf_cpu_map *perf_cpu_map__new_online_cpus(void);
  *                     perf_cpu_map__new_online_cpus is returned.
  */
 LIBPERF_API struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list);
-LIBPERF_API struct perf_cpu_map *perf_cpu_map__read(FILE *file);
 LIBPERF_API struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map);
 LIBPERF_API struct perf_cpu_map *perf_cpu_map__merge(struct perf_cpu_map *orig,
 						     struct perf_cpu_map *other);

tools/lib/perf/libperf.map

@@ -6,7 +6,6 @@ LIBPERF_0.0.1 {
 		perf_cpu_map__get;
 		perf_cpu_map__put;
 		perf_cpu_map__new;
-		perf_cpu_map__read;
 		perf_cpu_map__nr;
 		perf_cpu_map__cpu;
 		perf_cpu_map__has_any_cpu_or_is_empty;