From 1cef50e317c3395c6e8451f2b82a155db6ef2b42 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Sat, 15 Jun 2013 09:36:02 -0400 Subject: [PATCH] tty: Fix flip buffer free list Since flip buffers are size-aligned to 256 bytes and all flip buffers 512-bytes or larger are not added to the free list, the free list only contains 256-byte flip buffers. Remove the list search when allocating a new flip buffer. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_buffer.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index 170674c..a5e3962 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -18,6 +18,10 @@ #include #include + +#define MIN_TTYB_SIZE 256 +#define TTYB_ALIGN_MASK 255 + /** * tty_buffer_free_all - free buffers used by a tty * @tty: tty to free from @@ -94,7 +98,7 @@ static void tty_buffer_free(struct tty_port *port, struct tty_buffer *b) buf->memory_used -= b->size; WARN_ON(buf->memory_used < 0); - if (b->size >= 512) + if (b->size > MIN_TTYB_SIZE) kfree(b); else { b->next = buf->free; @@ -176,9 +180,10 @@ void tty_buffer_flush(struct tty_struct *tty) static struct tty_buffer *tty_buffer_find(struct tty_port *port, size_t size) { struct tty_buffer **tbh = &port->buf.free; - while ((*tbh) != NULL) { - struct tty_buffer *t = *tbh; - if (t->size >= size) { + if (size <= MIN_TTYB_SIZE) { + if (*tbh) { + struct tty_buffer *t = *tbh; + *tbh = t->next; t->next = NULL; t->used = 0; @@ -187,10 +192,9 @@ static struct tty_buffer *tty_buffer_find(struct tty_port *port, size_t size) port->buf.memory_used += t->size; return t; } - tbh = &((*tbh)->next); } /* Round the buffer size out */ - size = (size + 0xFF) & ~0xFF; + size = __ALIGN_MASK(size, TTYB_ALIGN_MASK); return tty_buffer_alloc(port, size); /* Should possibly check if this fails for the largest buffer we have queued and recycle that ? */ -- 2.7.4