1 files changed, 76 insertions, 9 deletions

diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c
index 573d3cc762c3..b2477caf09c2 100644
--- a/kernel/trace/ring_buffer_benchmark.c
+++ b/kernel/trace/ring_buffer_benchmark.c
@@ -35,6 +35,28 @@ static int disable_reader;
 module_param(disable_reader, uint, 0644);
 MODULE_PARM_DESC(disable_reader, "only run producer");
 
+static int write_iteration = 50;
+module_param(write_iteration, uint, 0644);
+MODULE_PARM_DESC(write_iteration, "# of writes between timestamp readings");
+
+static int producer_nice = 19;
+static int consumer_nice = 19;
+
+static int producer_fifo = -1;
+static int consumer_fifo = -1;
+
+module_param(producer_nice, uint, 0644);
+MODULE_PARM_DESC(producer_nice, "nice prio for producer");
+
+module_param(consumer_nice, uint, 0644);
+MODULE_PARM_DESC(consumer_nice, "nice prio for consumer");
+
+module_param(producer_fifo, uint, 0644);
+MODULE_PARM_DESC(producer_fifo, "fifo prio for producer");
+
+module_param(consumer_fifo, uint, 0644);
+MODULE_PARM_DESC(consumer_fifo, "fifo prio for consumer");
+
 static int read_events;
 
 static int kill_test;
@@ -208,15 +230,18 @@ static void ring_buffer_producer(void)
         do {
                 struct ring_buffer_event *event;
                 int *entry;
-
-                event = ring_buffer_lock_reserve(buffer, 10);
-                if (!event) {
-                        missed++;
-                } else {
-                        hit++;
-                        entry = ring_buffer_event_data(event);
-                        *entry = smp_processor_id();
-                        ring_buffer_unlock_commit(buffer, event);
+                int i;
+
+                for (i = 0; i < write_iteration; i++) {
+                        event = ring_buffer_lock_reserve(buffer, 10);
+                        if (!event) {
+                                missed++;
+                        } else {
+                                hit++;
+                                entry = ring_buffer_event_data(event);
+                                *entry = smp_processor_id();
+                                ring_buffer_unlock_commit(buffer, event);
+                        }
                 }
                 do_gettimeofday(&end_tv);
 
@@ -263,6 +288,27 @@ static void ring_buffer_producer(void)
 
         if (kill_test)
                 trace_printk("ERROR!\n");
+
+        if (!disable_reader) {
+                if (consumer_fifo < 0)
+                        trace_printk("Running Consumer at nice: %d\n",
+                                     consumer_nice);
+                else
+                        trace_printk("Running Consumer at SCHED_FIFO %d\n",
+                                     consumer_fifo);
+        }
+        if (producer_fifo < 0)
+                trace_printk("Running Producer at nice: %d\n",
+                             producer_nice);
+        else
+                trace_printk("Running Producer at SCHED_FIFO %d\n",
+                             producer_fifo);
+
+        /* Let the user know that the test is running at low priority */
+        if (producer_fifo < 0 && consumer_fifo < 0 &&
+            producer_nice == 19 && consumer_nice == 19)
+                trace_printk("WARNING!!! This test is running at lowest priority.\n");
+
         trace_printk("Time:     %lld (usecs)\n", time);
         trace_printk("Overruns: %lld\n", overruns);
         if (disable_reader)
@@ -392,6 +438,27 @@ static int __init ring_buffer_benchmark_init(void)
         if (IS_ERR(producer))
                 goto out_kill;
 
+        /*
+         * Run them as low-prio background tasks by default:
+         */
+        if (!disable_reader) {
+                if (consumer_fifo >= 0) {
+                        struct sched_param param = {
+                                .sched_priority = consumer_fifo
+                        };
+                        sched_setscheduler(consumer, SCHED_FIFO, &param);
+                } else
+                        set_user_nice(consumer, consumer_nice);
+        }
+
+        if (producer_fifo >= 0) {
+                struct sched_param param = {
+                        .sched_priority = consumer_fifo
+                };
+                sched_setscheduler(producer, SCHED_FIFO, &param);
+        } else
+                set_user_nice(producer, producer_nice);
+
         return 0;
 
  out_kill: