Re: [RFC 5/5] pm: remove kernel thread freezing

From: Shuah Khan
Date: Tue Oct 03 2017 - 17:10:02 EST

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

-- Shuah