On Saturday, 17 of November 2007, 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? > > > > 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). Actually, not even that one. You're right anyway. Below is a patch that IMO should fix the issue with apm_ioctl(). Greetings, Rafael --- From: Rafael J. Wysocki <rjw@xxxxxxx> The code in apm_ioctl() allows user space tasks waiting for a suspend to complete to be woken up prematurely as a result of the thawing of tasks carried out by the freezer. Fix it. Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> --- drivers/char/apm-emulation.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6/drivers/char/apm-emulation.c =================================================================== --- linux-2.6.orig/drivers/char/apm-emulation.c +++ linux-2.6/drivers/char/apm-emulation.c @@ -364,7 +364,7 @@ apm_ioctl(struct inode * inode, struct f */ flags = current->flags; - wait_event_interruptible(apm_suspend_waitqueue, + wait_event_freezable(apm_suspend_waitqueue, as->suspend_state == SUSPEND_DONE); } _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
