sched_trace: make buffer size configurable

Large sched_trace buffers cause boot problems on the ARM box. Allow
the user to specify smaller buffers.

1 files changed, 4 insertions, 1 deletions

diff --git a/litmus/sched_task_trace.c b/litmus/sched_task_trace.c
index 39a543e22d41..5fcabb55eb8f 100644
--- a/litmus/sched_task_trace.c
+++ b/litmus/sched_task_trace.c
@@ -18,7 +18,7 @@
 
 /* set MAJOR to 0 to have it dynamically assigned */
 #define FT_TASK_TRACE_MAJOR     253
-#define NO_EVENTS               4096 /* this is a buffer of 12 4k pages per CPU */
+#define NO_EVENTS               (1 << CONFIG_SCHED_TASK_TRACE_SHIFT)
 
 #define now() litmus_clock()
 
@@ -41,6 +41,9 @@ static int __init init_sched_task_trace(void)
 {
         struct local_buffer* buf;
         int i, ok = 0;
+        printk("Allocated %u sched_trace_xxx() events per CPU "
+               "(buffer size: %u bytes)\n",
+               NO_EVENTS, sizeof(struct local_buffer));
         ftdev_init(&st_dev, THIS_MODULE);
         for (i = 0; i < NR_CPUS; i++) {
                 buf = &per_cpu(st_event_buffer, i);