lkml.org 
[lkml]   [2014]   [Jun]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH tty-next 14/22] tty: Remove tty_wait_until_sent_from_close()
    Date
    On Monday 16 June 2014 09:17:11 Peter Hurley wrote:
    > tty_wait_until_sent_from_close() drops the tty lock while waiting
    > for the tty driver to finish sending previously accepted data (ie.,
    > data remaining in its write buffer and transmit fifo).
    >
    > However, dropping the tty lock is a hold-over from when the tty
    > lock was system-wide; ie., one lock for all ttys.
    >
    > Since commit 89c8d91e31f267703e365593f6bfebb9f6d2ad01,
    > 'tty: localise the lock', dropping the tty lock has not been necessary.
    >
    > CC: Karsten Keil <isdn@linux-pingi.de>
    > CC: linuxppc-dev@lists.ozlabs.org
    > Signed-off-by: Peter Hurley <peter@hurleysoftware.com>

    I don't understand the second half of the changelog, it doesn't seem
    to fit here: there deadlock that we are trying to avoid here happens
    when the *same* tty needs the lock to complete the function that
    sends the pending data. I don't think we do still do that any more,
    but it doesn't seem related to the tty lock being system-wide or not.

    Arnd


    \
     
     \ /
      Last update: 2014-06-17 10:41    [W:4.120 / U:0.036 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site