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| author | Alan Cox <alan@lxorguk.ukuu.org.uk> | 2008-04-30 00:53:29 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-30 08:29:40 -0700 |
| commit | 04f378b198da233ca0aca341b113dc6579d46123 (patch) | |
| tree | 696e7bd401125cee71ecaa2047c4273f38732554 /drivers/char/pty.c | |
| parent | e52384426064bca0669a954736206adca7595d48 (diff) | |
| download | linux-04f378b198da233ca0aca341b113dc6579d46123.tar.gz linux-04f378b198da233ca0aca341b113dc6579d46123.tar.bz2 linux-04f378b198da233ca0aca341b113dc6579d46123.zip | |
tty: BKL pushdown
- Push the BKL down into the line disciplines
- Switch the tty layer to unlocked_ioctl
- Introduce a new ctrl_lock spin lock for the control bits
- Eliminate much of the lock_kernel use in n_tty
- Prepare to (but don't yet) call the drivers with the lock dropped
on the paths that historically held the lock
BKL now primarily protects open/close/ldisc change in the tty layer
[jirislaby@gmail.com: a couple of fixes]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char/pty.c')
| -rw-r--r-- | drivers/char/pty.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/char/pty.c b/drivers/char/pty.c index 706ff34728f1..6288356b769d 100644 --- a/drivers/char/pty.c +++ b/drivers/char/pty.c @@ -181,6 +181,7 @@ static int pty_set_lock(struct tty_struct *tty, int __user * arg) static void pty_flush_buffer(struct tty_struct *tty) { struct tty_struct *to = tty->link; + unsigned long flags; if (!to) return; @@ -189,8 +190,10 @@ static void pty_flush_buffer(struct tty_struct *tty) to->ldisc.flush_buffer(to); if (to->packet) { + spin_lock_irqsave(&tty->ctrl_lock, flags); tty->ctrl_status |= TIOCPKT_FLUSHWRITE; wake_up_interruptible(&to->read_wait); + spin_unlock_irqrestore(&tty->ctrl_lock, flags); } } |