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>

1 files changed, 8 insertions, 6 deletions

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index d7e8ea690864..ae6fa6050925 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -808,6 +808,12 @@ struct perf_event_context {
         struct rcu_head                 rcu_head;
 };
 
+/*
+ * Number of contexts where an event can trigger:
+ *      task, softirq, hardirq, nmi.
+ */
+#define PERF_NR_CONTEXTS        4
+
 /**
  * struct perf_event_cpu_context - per cpu event context structure
  */
@@ -821,12 +827,8 @@ struct perf_cpu_context {
         struct mutex                    hlist_mutex;
         int                             hlist_refcount;
 
-        /*
-         * Recursion avoidance:
-         *
-         * task, softirq, irq, nmi context
-         */
-        int                             recursion[4];
+        /* Recursion avoidance in each contexts */
+        int                             recursion[PERF_NR_CONTEXTS];
 };
 
 struct perf_output_handle {