On Mon, 2017-02-13 at 13:21 +1300, Eric W. Biederman wrote: > > Good point, at the very least we should call remove if shutdown doesn't > > exist. Eric: could we make the changes Ben suggests? > > Definitely. That was the original design of the kexec interface > but people were worried about calling remove during reboot might > introduce regressions on the reboot functionality. So shutdown was > added to be remove without the cleaning up the kernel data structures. Right. Part of the problem was also that remove was dependent on CONFIG_HOTPLUG though that's no longer the case anymore. The problem is that a bunch of drivers either don't have a shutdown or worse, have one that actually shuts the HW down rather than "idle" it which puts it in a state that the new kernel can't deal with. > I am all for changing the core to call remove. That seems to be a more > tested code path (because remove tends to be part of the development > path for modules) and thus much more likely to work in practice. > > The challenge with changes in this area is that when the infrastructure > is changed for everyone someone needs to baby sit it until all of the > unexpected issues are resolved. I was hoping a couple of years ago that > Ben could be that person. Correct. And I lack time. But since we are a platform that uses kexec daily as our main booting mechanism we should probably be the ones driving that. I had a patch at least to fallback to remove in absence of shutdown which I can try to dig out. We can add a config option to make it do the other way around that we should start testing internally. I'm sure we will find 1 or 2 regressions as drivers do weird things. Cheers, Ben.
