lkml.org 
[lkml]   [2007]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: apm emulation driver broken ?
    Rafael J. Wysocki wrote:
    > On Saturday, 17 of November 2007, Franck Bui-Huu wrote:
    >> Rafael J. Wysocki wrote:
    >>> However, using PF_NOFREEZE to prevent this from happening doesn't seem to be
    >>> a good idea.
    >>>
    >> Indeed but...
    >>
    >>> I'd probably use wait_event_freezable() (defined in
    >>> include/linux/freezer.h) for that.
    >> ...I would just revert this bits from now to make sure this driver
    >> work again for v2.6.24.
    >
    > I'd prefer not to.
    >
    > The PF_NOFREEZE was not present in 2.6.23 already and I wouldn't like to
    > reintroduce it now.
    >
    > Why do you think that using wait_event_freezable() would not work, BTW?
    >

    I've never claimed this. I just said it may be safer to revert the
    changes for v2.6.24 and improve the current code for next releases.

    >>> It tries to send them fake signals and waits for them to freeze. If
    >>> they don't freeze within the timeout, it fails and clears their
    >>> TIF_FREEZE bits.
    >> But send_fake_signal() seems to wake up task in INTERRUPTIBLE state
    >> only. Looking at signal_wake_up(), it basically do:
    >>
    >> wake_up_state(t, TASK_INTERRUPTIBLE);
    >>
    >> What am I missing ?
    >
    > Nothing. :-)
    >
    > I didn't remember the change that made the freezer use TASK_INTERRUPTIBLE
    > explicitly in there (should have looked at the current code before replying).
    >

    ok so now we agreed on this point, can we assert that a user
    land thread waiting for an event in an UNINTERRUPTIBLE state
    will prevent a suspend to happen ?

    Franck
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-11-17 13:01    [W:0.033 / U:1.416 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site