commit fa6f0cc751d377af3f4f1484bceb47dc10163753
author Rasmus Villemoes <linux@rasmusvillemoes.dk> Sat Nov 08 21:42:10 2014 +0100
committer Steven Rostedt <rostedt@goodmis.org> Thu Nov 13 21:32:19 2014 -0500
tree 4605e7d420b5847228a78373737653e5563c7da1
parent 8520dedbbf7578a397ecdfcf6ab83f775f914cfe

tracing: Replace seq_printf by simpler equivalents

Using seq_printf to print a simple string or a single character is a
lot more expensive than it needs to be, since seq_puts and seq_putc
exist.

These patches do

  seq_printf(m, s) -> seq_puts(m, s)
  seq_printf(m, "%s", s) -> seq_puts(m, s)
  seq_printf(m, "%c", c) -> seq_putc(m, c)

Subsequent patches will simplify further.

Link: http://lkml.kernel.org/r/1415479332-25944-2-git-send-email-linux@rasmusvillemoes.dk

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/ftrace.c

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1a13e61..6233f91 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -571,13 +571,13 @@
 static int function_stat_headers(struct seq_file *m)
 {
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	seq_printf(m, "  Function                               "
-		   "Hit    Time            Avg             s^2\n"
-		      "  --------                               "
-		   "---    ----            ---             ---\n");
+	seq_puts(m, "  Function                               "
+		 "Hit    Time            Avg             s^2\n"
+		    "  --------                               "
+		 "---    ----            ---             ---\n");
 #else
-	seq_printf(m, "  Function                               Hit\n"
-		      "  --------                               ---\n");
+	seq_puts(m, "  Function                               Hit\n"
+		    "  --------                               ---\n");
 #endif
 	return 0;
 }
@@ -604,7 +604,7 @@
 	seq_printf(m, "  %-30.30s  %10lu", str, rec->counter);
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	seq_printf(m, "    ");
+	seq_puts(m, "    ");
 	avg = rec->time;
 	do_div(avg, rec->counter);
 
@@ -3006,9 +3006,9 @@
 
 	if (iter->flags & FTRACE_ITER_PRINTALL) {
 		if (iter->flags & FTRACE_ITER_NOTRACE)
-			seq_printf(m, "#### no functions disabled ####\n");
+			seq_puts(m, "#### no functions disabled ####\n");
 		else
-			seq_printf(m, "#### all functions enabled ####\n");
+			seq_puts(m, "#### all functions enabled ####\n");
 		return 0;
 	}
 
@@ -3030,13 +3030,13 @@
 				seq_printf(m, "\ttramp: %pS",
 					   (void *)ops->trampoline);
 			else
-				seq_printf(m, "\ttramp: ERROR!");
+				seq_puts(m, "\ttramp: ERROR!");
 
 		}
 		add_trampoline_func(m, ops, rec);
 	}	
 
-	seq_printf(m, "\n");
+	seq_putc(m, '\n');
 
 	return 0;
 }
@@ -4233,9 +4233,9 @@
 		struct ftrace_graph_data *fgd = m->private;
 
 		if (fgd->table == ftrace_graph_funcs)
-			seq_printf(m, "#### all functions enabled ####\n");
+			seq_puts(m, "#### all functions enabled ####\n");
 		else
-			seq_printf(m, "#### no functions disabled ####\n");
+			seq_puts(m, "#### no functions disabled ####\n");
 		return 0;
 	}
 
@@ -5155,12 +5155,12 @@
 	const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
 
 	if (v == (void *)1) {
-		seq_printf(m, "no pid\n");
+		seq_puts(m, "no pid\n");
 		return 0;
 	}
 
 	if (fpid->pid == ftrace_swapper_pid)
-		seq_printf(m, "swapper tasks\n");
+		seq_puts(m, "swapper tasks\n");
 	else
 		seq_printf(m, "%u\n", pid_vnr(fpid->pid));