ftrace: Reuse the output of the function tracer for func_repeats
authorSteven Rostedt (VMware) <rostedt@goodmis.org>
Thu, 15 Apr 2021 20:34:26 +0000 (16:34 -0400)
committerSteven Rostedt (VMware) <rostedt@goodmis.org>
Thu, 15 Apr 2021 20:34:26 +0000 (16:34 -0400)
The func_repeats event shows the output of the function tracer followed by
a count of the number of repeats the previous function had made, as well
as the timestamp of the last function that was repeated.

The printing of the function should be the same as is for the function it
is displaying. Reuse the code in trace_fn_trace() by making a helper
function print_fn_trace() and use it for trace_func_repeats_print().

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
kernel/trace/trace_output.c

index 3037f0c..d0368a5 100644 (file)
@@ -845,6 +845,17 @@ enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
        return trace_handle_return(&iter->seq);
 }
 
+static void print_fn_trace(struct trace_seq *s, unsigned long ip,
+                          unsigned long parent_ip, int flags)
+{
+       seq_print_ip_sym(s, ip, flags);
+
+       if ((flags & TRACE_ITER_PRINT_PARENT) && parent_ip) {
+               trace_seq_puts(s, " <-");
+               seq_print_ip_sym(s, parent_ip, flags);
+       }
+}
+
 /* TRACE_FN */
 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
                                        struct trace_event *event)
@@ -854,13 +865,7 @@ static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 
        trace_assign_type(field, iter->ent);
 
-       seq_print_ip_sym(s, field->ip, flags);
-
-       if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
-               trace_seq_puts(s, " <-");
-               seq_print_ip_sym(s, field->parent_ip, flags);
-       }
-
+       print_fn_trace(s, field->ip, field->parent_ip, flags);
        trace_seq_putc(s, '\n');
 
        return trace_handle_return(s);
@@ -1408,9 +1413,7 @@ trace_func_repeats_print(struct trace_iterator *iter, int flags,
 
        trace_assign_type(field, iter->ent);
 
-       seq_print_ip_sym(s, field->ip, flags);
-       trace_seq_puts(s, " <-");
-       seq_print_ip_sym(s, field->parent_ip, flags);
+       print_fn_trace(s, field->ip, field->parent_ip, flags);
        trace_seq_printf(s, " (repeats: %u, last_ts:", field->count);
        trace_print_time(s, iter,
                         iter->ts - FUNC_REPEATS_GET_DELTA_TS(field));