---

yaml --- r: 185206 b: refs/heads/master c: d9661ad h: refs/heads/master v: v3
git-mirror · Mar 2, 2010 · f434d05 · f434d05
1 parent f036547
commit f434d05
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Showing 3 changed files with 15 additions and 3 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4165fe4ef7305609a96c7f248cefb9c414d0ede5
+refs/heads/master: d9661adfb8e53a7647360140af3b92284cbe52d4
diff --git a/trunk/drivers/char/tty_buffer.c b/trunk/drivers/char/tty_buffer.c
@@ -247,7 +247,8 @@ int tty_insert_flip_string(struct tty_struct *tty, const unsigned char *chars,
 {
 	int copied = 0;
 	do {
-		int space = tty_buffer_request_room(tty, size - copied);
+		int goal = min(size - copied, TTY_BUFFER_PAGE);
+		int space = tty_buffer_request_room(tty, goal);
 		struct tty_buffer *tb = tty->buf.tail;
 		/* If there is no space then tb may be NULL */
 		if (unlikely(space == 0))
@@ -283,7 +284,8 @@ int tty_insert_flip_string_flags(struct tty_struct *tty,
 {
 	int copied = 0;
 	do {
-		int space = tty_buffer_request_room(tty, size - copied);
+		int goal = min(size - copied, TTY_BUFFER_PAGE);
+		int space = tty_buffer_request_room(tty, goal);
 		struct tty_buffer *tb = tty->buf.tail;
 		/* If there is no space then tb may be NULL */
 		if (unlikely(space == 0))

diff --git a/trunk/include/linux/tty.h b/trunk/include/linux/tty.h
@@ -68,6 +68,16 @@ struct tty_buffer {
 	unsigned long data[0];
 };
 
+/*
+ * We default to dicing tty buffer allocations to this many characters
+ * in order to avoid multiple page allocations. We assume tty_buffer itself
+ * is under 256 bytes. See tty_buffer_find for the allocation logic this
+ * must match
+ */
+
+#define TTY_BUFFER_PAGE		((PAGE_SIZE  - 256) / 2)
+
+
 struct tty_bufhead {
 	struct delayed_work work;
 	spinlock_t lock;