On Thu, 2007-07-05 at 10:23 -0400, Alan Stern wrote: > > How will that help? Block the kernel thread in the freezer or block it > in the driver -- either way it is blocked. So how do your deadlocks > get resolved? Because nobody is waiting on that kernel thread anyway without a freezer so there is no deadlock anymore. > I disagree with your analysis -- not that it's completely wrong, but it > points out an existing basic problem in the kernel. The kernel should > never depend on userspace! More correctly, a task executing in the > kernel should never block with any sort of mutex or other lock held (in > a way that would preclude it from being frozen, let's say) while > waiting for a response from userspace. > > Then the dependency graph would be easy to construct: User tasks can > depend on whatever they want, and kernel threads never depend on a user > task. In an idea world, there would be no hunger... > If this contradicts the existing implementations and APIs for userspace > filesystems, then so be it. My conclusion would be that the > implementations and APIs should be changed. Why are you guys working so hard and spending so much energy to try to avoid doing the right thing is beyond my understanding... > It _does_ apply to kernel threads. That's exactly why I wrote above > that kernel threads which try to do I/O during a suspend will need > extra attention. Ok none at all if you don't have a freezer. Ben. _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
