ftrace: display start of CPU buffer in trace output

[linux-2.6-omap-h63xx.git] / kernel / trace / trace.c

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 58435415b366402e35b7f38883539f418ebcebcc..f147f198b9a690ab634db0b39486fe492004c568 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1478,6 +1478,17 @@ void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter)
                trace_seq_putc(s, '\n');
 }
 
+static void test_cpu_buff_start(struct trace_iterator *iter)
+{
+       struct trace_seq *s = &iter->seq;
+
+       if (cpu_isset(iter->cpu, iter->started))
+               return;
+
+       cpu_set(iter->cpu, iter->started);
+       trace_seq_printf(s, "##### CPU %u buffer started ####\n", iter->cpu);
+}
+
 static enum print_line_t
 print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 {
@@ -1497,6 +1508,8 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
        if (entry->type == TRACE_CONT)
                return TRACE_TYPE_HANDLED;
 
+       test_cpu_buff_start(iter);
+
        next_entry = find_next_entry(iter, NULL, &next_ts);
        if (!next_entry)
                next_ts = iter->ts;
@@ -1612,6 +1625,8 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
        if (entry->type == TRACE_CONT)
                return TRACE_TYPE_HANDLED;
 
+       test_cpu_buff_start(iter);
+
        comm = trace_find_cmdline(iter->ent->pid);
 
        t = ns2usecs(iter->ts);
@@ -2631,6 +2646,10 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
                return -ENOMEM;
 
        mutex_lock(&trace_types_lock);
+
+       /* trace pipe does not show start of buffer */
+       cpus_setall(iter->started);
+
        iter->tr = &global_trace;
        iter->trace = current_trace;
        filp->private_data = iter;