perf tools: Refactor cpumap to hold nr and the map

So that later, we can pass the cpu_map instance instead of (nr_cpus, cpu_map)
for things like perf_evsel__open and friends.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/cpumap.c

@@ -4,32 +4,53 @@
 #include <assert.h>
 #include <stdio.h>
 
-int cpumap[MAX_NR_CPUS];
-
-static int default_cpu_map(void)
+static struct cpu_map *cpu_map__default_new(void)
 {
-	int nr_cpus, i;
+	struct cpu_map *cpus;
+	int nr_cpus;
 
 	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
-	assert(nr_cpus <= MAX_NR_CPUS);
-	assert((int)nr_cpus >= 0);
+	if (nr_cpus < 0)
+		return NULL;
 
-	for (i = 0; i < nr_cpus; ++i)
-		cpumap[i] = i;
+	cpus = malloc(sizeof(*cpus) + nr_cpus * sizeof(int));
+	if (cpus != NULL) {
+		int i;
+		for (i = 0; i < nr_cpus; ++i)
+			cpus->map[i] = i;
 
-	return nr_cpus;
+		cpus->nr = nr_cpus;
+	}
+
+	return cpus;
 }
 
-static int read_all_cpu_map(void)
+static struct cpu_map *cpu_map__trim_new(int nr_cpus, int *tmp_cpus)
 {
+	size_t payload_size = nr_cpus * sizeof(int);
+	struct cpu_map *cpus = malloc(sizeof(*cpus) + payload_size);
+
+	if (cpus != NULL) {
+		cpus->nr = nr_cpus;
+		memcpy(cpus->map, tmp_cpus, payload_size);
+	}
+
+	return cpus;
+}
+
+static struct cpu_map *cpu_map__read_all_cpu_map(void)
+{
+	struct cpu_map *cpus = NULL;
 	FILE *onlnf;
 	int nr_cpus = 0;
+	int *tmp_cpus = NULL, *tmp;
+	int max_entries = 0;
 	int n, cpu, prev;
 	char sep;
 
 	onlnf = fopen("/sys/devices/system/cpu/online", "r");
 	if (!onlnf)
-		return default_cpu_map();
+		return cpu_map__default_new();
 
 	sep = 0;
 	prev = -1;
@@ -38,12 +59,28 @@ static int read_all_cpu_map(void)
 		if (n <= 0)
 			break;
 		if (prev >= 0) {
-			assert(nr_cpus + cpu - prev - 1 < MAX_NR_CPUS);
+			int new_max = nr_cpus + cpu - prev - 1;
+
+			if (new_max >= max_entries) {
+				max_entries = new_max + MAX_NR_CPUS / 2;
+				tmp = realloc(tmp_cpus, max_entries * sizeof(int));
+				if (tmp == NULL)
+					goto out_free_tmp;
+				tmp_cpus = tmp;
+			}
+
 			while (++prev < cpu)
-				cpumap[nr_cpus++] = prev;
+				tmp_cpus[nr_cpus++] = prev;
 		}
-		assert (nr_cpus < MAX_NR_CPUS);
-		cpumap[nr_cpus++] = cpu;
+		if (nr_cpus == max_entries) {
+			max_entries += MAX_NR_CPUS;
+			tmp = realloc(tmp_cpus, max_entries * sizeof(int));
+			if (tmp == NULL)
+				goto out_free_tmp;
+			tmp_cpus = tmp;
+		}
+
+		tmp_cpus[nr_cpus++] = cpu;
 		if (n == 2 && sep == '-')
 			prev = cpu;
 		else
@@ -51,24 +88,31 @@ static int read_all_cpu_map(void)
 		if (n == 1 || sep == '\n')
 			break;
 	}
-	fclose(onlnf);
-	if (nr_cpus > 0)
-		return nr_cpus;
 
-	return default_cpu_map();
+	if (nr_cpus > 0)
+		cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
+	else
+		cpus = cpu_map__default_new();
+out_free_tmp:
+	free(tmp_cpus);
+	fclose(onlnf);
+	return cpus;
 }
 
-int read_cpu_map(const char *cpu_list)
+struct cpu_map *cpu_map__new(const char *cpu_list)
 {
+	struct cpu_map *cpus = NULL;
 	unsigned long start_cpu, end_cpu = 0;
 	char *p = NULL;
 	int i, nr_cpus = 0;
+	int *tmp_cpus = NULL, *tmp;
+	int max_entries = 0;
 
 	if (!cpu_list)
-		return read_all_cpu_map();
+		return cpu_map__read_all_cpu_map();
 
 	if (!isdigit(*cpu_list))
-		goto invalid;
+		goto out;
 
 	while (isdigit(*cpu_list)) {
 		p = NULL;
@@ -94,21 +138,42 @@ int read_cpu_map(const char *cpu_list)
 		for (; start_cpu <= end_cpu; start_cpu++) {
 			/* check for duplicates */
 			for (i = 0; i < nr_cpus; i++)
-				if (cpumap[i] == (int)start_cpu)
+				if (tmp_cpus[i] == (int)start_cpu)
 					goto invalid;
 
-			assert(nr_cpus < MAX_NR_CPUS);
-			cpumap[nr_cpus++] = (int)start_cpu;
+			if (nr_cpus == max_entries) {
+				max_entries += MAX_NR_CPUS;
+				tmp = realloc(tmp_cpus, max_entries * sizeof(int));
+				if (tmp == NULL)
+					goto invalid;
+				tmp_cpus = tmp;
+			}
+			tmp_cpus[nr_cpus++] = (int)start_cpu;
 		}
 		if (*p)
 			++p;
 
 		cpu_list = p;
 	}
-	if (nr_cpus > 0)
-		return nr_cpus;
 
-	return default_cpu_map();
+	if (nr_cpus > 0)
+		cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
+	else
+		cpus = cpu_map__default_new();
 invalid:
-	return -1;
+	free(tmp_cpus);
+out:
+	return cpus;
+}
+
+struct cpu_map *cpu_map__dummy_new(void)
+{
+	struct cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(int));
+
+	if (cpus != NULL) {
+		cpus->nr = 1;
+		cpus->map[0] = -1;
+	}
+
+	return cpus;
 }