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@hpe.com>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Link: http://lore.kernel.org/lkml/20190827214352.94272-6-meyerk@stormcage.eag.rdlabs.hpecorp.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 93483f1764d3..a1542b4c047b 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;