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| author |   Peter Hurley <peter@hurleysoftware.com> | 2013-12-02 14:24:46 -0500 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-08 16:53:13 -0800 |
| commit | 6c67716d64103e5a8e23c45dcdfc76520033d479 (patch) | |
| tree | ce3babac26955cac5af89bba2d8906e7bac42f72 /drivers/tty/n_tty.c | |
| parent | n_tty: Refactor input_available_p() by call site (diff) | |
| download | linux-dev-6c67716d64103e5a8e23c45dcdfc76520033d479.tar.xz linux-dev-6c67716d64103e5a8e23c45dcdfc76520033d479.zip | |
n_tty: Only perform wakeups for waiters
Only wakeup the _waiting_ reader, polls and/or writer(s).
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/n_tty.c')
| -rw-r--r-- | drivers/tty/n_tty.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 2caa2936d1b1..c7f8f7bc1423 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -274,7 +274,8 @@ static void n_tty_check_unthrottle(struct tty_struct *tty) return; n_tty_set_room(tty); n_tty_write_wakeup(tty->link); - wake_up_interruptible_poll(&tty->link->write_wait, POLLOUT); + if (waitqueue_active(&tty->link->write_wait)) + wake_up_interruptible_poll(&tty->link->write_wait, POLLOUT); return; } @@ -349,7 +350,8 @@ static void n_tty_packet_mode_flush(struct tty_struct *tty) spin_lock_irqsave(&tty->ctrl_lock, flags); if (tty->link->packet) { tty->ctrl_status |= TIOCPKT_FLUSHREAD; - wake_up_interruptible(&tty->link->read_wait); + if (waitqueue_active(&tty->link->read_wait)) + wake_up_interruptible(&tty->link->read_wait); } spin_unlock_irqrestore(&tty->ctrl_lock, flags); } @@ -1155,7 +1157,8 @@ static void n_tty_receive_break(struct tty_struct *tty) put_tty_queue('\0', ldata); } put_tty_queue('\0', ldata); - wake_up_interruptible(&tty->read_wait); + if (waitqueue_active(&tty->read_wait)) + wake_up_interruptible(&tty->read_wait); } /** @@ -1213,7 +1216,8 @@ static void n_tty_receive_parity_error(struct tty_struct *tty, unsigned char c) put_tty_queue('\0', ldata); else put_tty_queue(c, ldata); - wake_up_interruptible(&tty->read_wait); + if (waitqueue_active(&tty->read_wait)) + wake_up_interruptible(&tty->read_wait); } static void @@ -1802,8 +1806,10 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) start_tty(tty); /* The termios change make the tty ready for I/O */ - wake_up_interruptible(&tty->write_wait); - wake_up_interruptible(&tty->read_wait); + if (waitqueue_active(&tty->write_wait)) + wake_up_interruptible(&tty->write_wait); + if (waitqueue_active(&tty->read_wait)) + wake_up_interruptible(&tty->read_wait); } /** |