Re: apm emulation driver broken ?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Saturday, 17 of November 2007, Franck Bui-Huu wrote:
> 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 ?

Yes.

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

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux