On Tue, Oct 3, 2017 at 3:00 PM, Jiri Kosina <jikos@xxxxxxxxxx> wrote: > On Tue, 3 Oct 2017, Pavel Machek wrote: > >> > Again, I agree that the (rare) kthreads that are actually "creating" new >> > I/O have to be somehow frozen and require special care. >> >> Agreed. Was any effort made to identify those special kernel threads? > > I don't think there is any other way than just inspecting all the > try_to_freeze() instances in the kernel, and understanding what that > particular kthread is doing. > > I've cleaned up most of the low-hanging fruit already, where the > try_to_freeze() was obviously completely pointless, but a lot more time > needs to be invested into this. > There are about 36 drivers that call try_to_freeze() and half (18 ) of those are media drivers. Maybe it is easier handle sub-system by sub-system basis for a review of which one of these usages could be removed. cc'ing Mauro and linux-media thanks, -- Shuah