[tip: perf/core] perf machine: Replace MAX_NR_CPUS with perf_env::nr_cpus_online

[tip-bot2 for Kyle Meyer]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     8c7274691f0de5fb56f3b9fe9208ce7e515a2d2c
Gitweb:        https://git.kernel.org/tip/8c7274691f0de5fb56f3b9fe9208ce7e515a2d2c
Author:        Kyle Meyer <meyerk@xxxxxxx>
AuthorDate:    Tue, 27 Aug 2019 16:43:50 -05:00
Committer:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Thu, 29 Aug 2019 17:38:32 -03:00

perf machine: Replace MAX_NR_CPUS with perf_env::nr_cpus_online

nr_cpus, the number of CPUs online during a record session bound by
MAX_NR_CPUS, can be used as a dynamic alternative for MAX_NR_CPUS in
__machine__synthesize_threads and machine__set_current_tid.

Signed-off-by: Kyle Meyer <kyle.meyer@xxxxxxx>
Reviewed-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Russ Anderson <russ.anderson@xxxxxxx>
Link: http://lore.kernel.org/lkml/20190827214352.94272-6-meyerk@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/machine.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 93483f1..a1542b4 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2619,7 +2619,9 @@ int __machine__synthesize_threads(struct machine *machine, struct perf_tool *too
 
 pid_t machine__get_current_tid(struct machine *machine, int cpu)
 {
-	if (cpu < 0 || cpu >= MAX_NR_CPUS || !machine->current_tid)
+	int nr_cpus = min(machine->env->nr_cpus_online, MAX_NR_CPUS);
+
+	if (cpu < 0 || cpu >= nr_cpus || !machine->current_tid)
 		return -1;
 
 	return machine->current_tid[cpu];
@@ -2629,6 +2631,7 @@ int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
 			     pid_t tid)
 {
 	struct thread *thread;
+	int nr_cpus = min(machine->env->nr_cpus_online, MAX_NR_CPUS);
 
 	if (cpu < 0)
 		return -EINVAL;
@@ -2636,14 +2639,14 @@ int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
 	if (!machine->current_tid) {
 		int i;
 
-		machine->current_tid = calloc(MAX_NR_CPUS, sizeof(pid_t));
+		machine->current_tid = calloc(nr_cpus, sizeof(pid_t));
 		if (!machine->current_tid)
 			return -ENOMEM;
-		for (i = 0; i < MAX_NR_CPUS; i++)
+		for (i = 0; i < nr_cpus; i++)
 			machine->current_tid[i] = -1;
 	}
 
-	if (cpu >= MAX_NR_CPUS) {
+	if (cpu >= nr_cpus) {
 		pr_err("Requested CPU %d too large. ", cpu);
 		pr_err("Consider raising MAX_NR_CPUS\n");
 		return -EINVAL;