Hi, On Thursday, 7 of April 2005 11:11, Pavel Machek wrote: > Hi! > > > > > > What happens if a process owns a lock needed to suspend a device and it is > > > > > waiting in TASK_UNINTERRUPTIBLE? > > > > > > > > Well, we're in trouble. :-) > > > > > > > > However, if any process that we have frozen owns such a lock, we're in trouble > > > > too. > > > > > > No, we are not. Processes can't own any locks when they are in > > > refrigerator... It is not ok to call refrigerator from any context > > > where you own a lock. > > > > I didn't mean a lock in general, but a lock that is needed to > > suspend a device. > > Processes in refrigerator are not allowed to own any locks. That means > they may not own a lock that is needed to suspend a device ;-). I am confused now. AFAICS, we don't check anywhere if a process we are going to freeze holds any locks. If we have a task in TASK_INTERRUPTIBLE, we just send it a fake signal which causes it to go to the refrigerator(). Could you please tell me how we prevent such a task from holding any locks? [It probably doesn't matter, at least practically, but ...? :-)] > OTOH... we may want to move completely away from refrigerator. Its > quite a hack, and it device support is okay, we'll not really need it. Still, it won't happen soon, I guess. :-) As of today, we have the refrigerator and the processes in TASK_UNINTERRUPTIBLE are mishandled. I think we should do something about it, at least for now, until we drop the refrigerator altogether (if we are going to drop it). That's why I started the discussion and sent the patch. Greets, Rafael -- - Would you tell me, please, which way I ought to go from here? - That depends a good deal on where you want to get to. -- Lewis Carroll "Alice's Adventures in Wonderland"
