printk: Optimize if statement logic where newline exists

In reviewing Kay's fix up patch: "printk: Have printk() never buffer its
data", I found two if statements that could be combined and optimized.

Put together the two 'cont.len && cont.owner == current' if statements
into a single one, and check if we need to call cont_add(). This also
removes the unneeded double cont_flush() calls.

Link: http://lkml.kernel.org/r/1340869133.876.10.camel@mop

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 7 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index fbf4d0b22a1d..5ae6b09e3805 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1496,15 +1496,14 @@ asmlinkage int vprintk_emit(int facility, int level,
                 bool stored = false;
 
                 /*
-                 * Flush the conflicting buffer. An earlier newline was missing,
-                 * or we race with a continuation line from an interrupt.
+                 * If an earlier newline was missing and it was the same task,
+                 * either merge it with the current buffer and flush, or if
+                 * there was a race with interrupts (prefix == true) then just
+                 * flush it out and store this line separately.
                  */
-                if (cont.len && prefix && cont.owner == current)
-                        cont_flush();
-
-                /* Merge with our buffer if possible; flush it in any case */
                 if (cont.len && cont.owner == current) {
-                        stored = cont_add(facility, level, text, text_len);
+                        if (!prefix)
+                                stored = cont_add(facility, level, text, text_len);
                         cont_flush();
                 }