3 files changed, 35 insertions, 6 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9e158cc84ced..fa5cee639962 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -338,7 +338,8 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
 /* trace_flags holds trace_options default values */
 unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
         TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME |
-        TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE;
+        TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE |
+        TRACE_ITER_IRQ_INFO;
 
 static int trace_stop_count;
 static DEFINE_RAW_SPINLOCK(tracing_start_lock);
@@ -426,6 +427,7 @@ static const char *trace_options[] = {
         "record-cmd",
         "overwrite",
         "disable_on_free",
+        "irq-info",
         NULL
 };
 
@@ -1857,10 +1859,20 @@ static void print_lat_help_header(struct seq_file *m)
 
 static void print_func_help_header(struct seq_file *m)
 {
-        seq_puts(m, "#           TASK-PID    CPU#    TIMESTAMP  FUNCTION\n");
+        seq_puts(m, "#           TASK-PID   CPU#      TIMESTAMP  FUNCTION\n");
         seq_puts(m, "#              | |       |          |         |\n");
 }
 
+static void print_func_help_header_irq(struct seq_file *m)
+{
+        seq_puts(m, "#                              _-----=> irqs-off\n");
+        seq_puts(m, "#                             / _----=> need-resched\n");
+        seq_puts(m, "#                            | / _---=> hardirq/softirq\n");
+        seq_puts(m, "#                            || / _--=> preempt-depth\n");
+        seq_puts(m, "#                            ||| /     delay\n");
+        seq_puts(m, "#           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION\n");
+        seq_puts(m, "#              | |       |   ||||       |         |\n");
+}
 
 void
 print_trace_header(struct seq_file *m, struct trace_iterator *iter)
@@ -2170,8 +2182,12 @@ void trace_default_header(struct seq_file *m)
                 if (!(trace_flags & TRACE_ITER_VERBOSE))
                         print_lat_help_header(m);
         } else {
-                if (!(trace_flags & TRACE_ITER_VERBOSE))
-                        print_func_help_header(m);
+                if (!(trace_flags & TRACE_ITER_VERBOSE)) {
+                        if (trace_flags & TRACE_ITER_IRQ_INFO)
+                                print_func_help_header_irq(m);
+                        else
+                                print_func_help_header(m);
+                }
         }
 }
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index f8ec2291b522..2c2657462ac3 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -655,6 +655,7 @@ enum trace_iterator_flags {
         TRACE_ITER_RECORD_CMD           = 0x100000,
         TRACE_ITER_OVERWRITE            = 0x200000,
         TRACE_ITER_STOP_ON_FREE         = 0x400000,
+        TRACE_ITER_IRQ_INFO             = 0x800000,
 };
 
 /*
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 51999309a6cf..0d6ff3555942 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -627,11 +627,23 @@ int trace_print_context(struct trace_iterator *iter)
         unsigned long usec_rem = do_div(t, USEC_PER_SEC);
         unsigned long secs = (unsigned long)t;
         char comm[TASK_COMM_LEN];
+        int ret;
 
         trace_find_cmdline(entry->pid, comm);
 
-        return trace_seq_printf(s, "%16s-%-5d [%03d] %5lu.%06lu: ",
-                                comm, entry->pid, iter->cpu, secs, usec_rem);
+        ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",
+                               comm, entry->pid, iter->cpu);
+        if (!ret)
+                return 0;
+
+        if (trace_flags & TRACE_ITER_IRQ_INFO) {
+                ret = trace_print_lat_fmt(s, entry);
+                if (!ret)
+                        return 0;
+        }
+
+        return trace_seq_printf(s, " %5lu.%06lu: ",
+                                secs, usec_rem);
 }
 
 int trace_print_lat_context(struct trace_iterator *iter)