John David Anglin <dave.anglin@xxxxxxxx> writes: > On 2021-10-17 12:30 p.m., Helge Deller wrote: >> It seems the warnings are gone if I remove the irq masking. >> I see the options: >> a) revert the irq masking in syscall.S. Not sure if it really hurts performance. >> b) revert the patch from Sven. >> c) insert code to turn back irq on in the fault handler if we are on the gateway page. >> What is your thought? > > After some thought, I believe option a) is the best. I no longer think interrupts can be > disabled in the futex and cmpxchg operations because of COW breaks. This not ideal but > I suspect it's the best we can do. > > For the cmpxchg operations in syscall.S, we rely on the code to not schedule off the gateway > page. For the futex, I added code to disable preemption. > > So far, I haven't seen the warnings with the attached change but the change is only lightly tested. Thanks Dave. I just applied it to my tree and will give it a spin.
