tty: move global ldisc idle waitqueue to the individual ldisc
The global wait_queue that is used for line discipline idle handling is
moved to a separate wait_queue for each line instance. This prevents
unnecessary blocking on one line, because of idle handling on another
line.
Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index fa65cde..173a900 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -28,7 +28,6 @@
static DEFINE_SPINLOCK(tty_ldisc_lock);
static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
-static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_idle);
/* Line disc dispatch table */
static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
@@ -65,7 +64,7 @@
return;
}
local_irq_restore(flags);
- wake_up(&tty_ldisc_idle);
+ wake_up(&ld->wq_idle);
}
/**
@@ -200,6 +199,8 @@
ld->ops = ldops;
atomic_set(&ld->users, 1);
+ init_waitqueue_head(&ld->wq_idle);
+
return ld;
}
@@ -538,7 +539,7 @@
static int tty_ldisc_wait_idle(struct tty_struct *tty, long timeout)
{
long ret;
- ret = wait_event_timeout(tty_ldisc_idle,
+ ret = wait_event_timeout(tty->ldisc->wq_idle,
atomic_read(&tty->ldisc->users) == 1, timeout);
return ret > 0 ? 0 : -EBUSY;
}