From: Linus Torvalds > Sent: 19 September 2023 18:25 > > On Tue, 19 Sept 2023 at 06:48, John Paul Adrian Glaubitz > <glaubitz@xxxxxxxxxxxxxxxxxxx> wrote: > > > > As Geert poined out, I'm not seeing anything particular problematic with the > > architectures lacking CONFIG_PREEMPT at the moment. This seems to be more > > something about organizing KConfig files. > > It can definitely be problematic. > > Not the Kconfig file part, and not the preempt count part itself. > > But the fact that it has never been used and tested means that there > might be tons of "this architecture code knows it's not preemptible, > because this architecture doesn't support preemption". Do distos even build x86 kernels with PREEMPT_FULL? I know I've had issues with massive latencies caused graphics driver forcing write-backs of all the framebuffer memory. (I think it is a failed attempt to fix a temporary display corruption.) OTOH SMP support and CONFIG_RT will test most of the code. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
