lkml.org 
[lkml]   [2013]   [Feb]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v3 16/23] tty: Make core responsible for synchronizing its work
    From
    Date
    On Tue, 2013-02-05 at 15:20 -0500, Peter Hurley wrote:
    > The tty core relies on the ldisc layer for synchronizing destruction
    > of the tty. Instead, the final tty release must wait for any pending tty
    > work to complete prior to tty destruction.
    >
    > Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
    > ---
    > drivers/tty/tty_io.c | 17 +++++++++++++++++
    > drivers/tty/tty_ldisc.c | 24 ++++--------------------
    > 2 files changed, 21 insertions(+), 20 deletions(-)

    ...

    > diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
    > index e0fdfec..c2837b2 100644
    > --- a/drivers/tty/tty_ldisc.c
    > +++ b/drivers/tty/tty_ldisc.c
    > @@ -499,18 +499,6 @@ static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
    > }
    >
    > /**
    > - * tty_ldisc_flush_works - flush all works of a tty
    > - * @tty: tty device to flush works for
    > - *
    > - * Sync flush all works belonging to @tty.
    > - */
    > -static void tty_ldisc_flush_works(struct tty_struct *tty)
    > -{
    > - flush_work(&tty->SAK_work);
    > - flush_work(&tty->hangup_work);
    > -}
    > -
    > -/**
    > * tty_ldisc_wait_idle - wait for the ldisc to become idle
    > * @tty: tty to wait for
    > * @timeout: for how long to wait at most
    > @@ -726,13 +714,13 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
    > retval = tty_ldisc_halt(tty, o_tty, &work, &o_work, 5 * HZ);
    >
    > /*
    > - * Wait for ->hangup_work to terminate.
    > + * Wait for hangup to complete, if pending.
    > * We must drop the mutex here in case a hangup is also in process.
    > */
    >
    > mutex_unlock(&tty->ldisc_mutex);
    >
    > - tty_ldisc_flush_works(tty);
    > + flush_work(&tty->hangup_work);

    Careful review will note that I dropped waiting for SAK. That's because
    it makes no sense to wait for SAK_work here -- ie., while setting a new
    ldisc. The SAK work can just as easily run at the completion of
    tty_set_ldisc() at tty_unlock().

    I believe this is an artifact of the formerly shared code.

    But maybe I should note that in the commit message?




    \
     
     \ /
      Last update: 2013-02-05 22:41    [W:3.666 / U:0.072 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site