perf: Humanize the number of contexts

Instead of hardcoding the number of contexts for the recursions
barriers, define a cpp constant to make the code more
self-explanatory.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>

2 files changed, 6 insertions, 6 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 75ab8a2df6b2..f416aef242c3 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1772,7 +1772,7 @@ struct callchain_cpus_entries {
         struct perf_callchain_entry     *cpu_entries[0];
 };
 
-static DEFINE_PER_CPU(int, callchain_recursion[4]);
+static DEFINE_PER_CPU(int, callchain_recursion[PERF_NR_CONTEXTS]);
 static atomic_t nr_callchain_events;
 static DEFINE_MUTEX(callchain_mutex);
 struct callchain_cpus_entries *callchain_cpus_entries;
@@ -1828,7 +1828,7 @@ static int alloc_callchain_buffers(void)
         if (!entries)
                 return -ENOMEM;
 
-        size = sizeof(struct perf_callchain_entry) * 4;
+        size = sizeof(struct perf_callchain_entry) * PERF_NR_CONTEXTS;
 
         for_each_possible_cpu(cpu) {
                 entries->cpu_entries[cpu] = kmalloc_node(size, GFP_KERNEL,
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 000e6e85b445..db2eae2efcf2 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -9,7 +9,7 @@
 #include <linux/kprobes.h>
 #include "trace.h"
 
-static char *perf_trace_buf[4];
+static char *perf_trace_buf[PERF_NR_CONTEXTS];
 
 /*
  * Force it to be aligned to unsigned long to avoid misaligned accesses
@@ -45,7 +45,7 @@ static int perf_trace_event_init(struct ftrace_event_call *tp_event,
                 char *buf;
                 int i;
 
-                for (i = 0; i < 4; i++) {
+                for (i = 0; i < PERF_NR_CONTEXTS; i++) {
                         buf = (char *)alloc_percpu(perf_trace_t);
                         if (!buf)
                                 goto fail;
@@ -65,7 +65,7 @@ fail:
         if (!total_ref_count) {
                 int i;
 
-                for (i = 0; i < 4; i++) {
+                for (i = 0; i < PERF_NR_CONTEXTS; i++) {
                         free_percpu(perf_trace_buf[i]);
                         perf_trace_buf[i] = NULL;
                 }
@@ -140,7 +140,7 @@ void perf_trace_destroy(struct perf_event *p_event)
         tp_event->perf_events = NULL;
 
         if (!--total_ref_count) {
-                for (i = 0; i < 4; i++) {
+                for (i = 0; i < PERF_NR_CONTEXTS; i++) {
                         free_percpu(perf_trace_buf[i]);
                         perf_trace_buf[i] = NULL;
                 }