On 2024-12-10 17:05:55 [+0100], Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@xxxxxxxx> > > CONFIG_HIGHPTE was added in linux-2.6.32, a few years before 64-bit > support. At the time it made sense, as the CONFIG_ARM_LPAE option allowed > systems with 16GB of memory that made lowmem a particularly scarce > resource, and the HIGHPTE implementation gave feature parity with 32-bit > x86 and frv machines. > > Since Arm is the last architecture remaining that uses this, and almost > no 32-bit machines support more than 4GB of RAM, the cost of continuing > to maintain HIGHPTE seems unjustified, so remove it here to allow > simplifying the generic page table handling. > > Link: https://lore.kernel.org/lkml/20241204103042.1904639-8-arnd@xxxxxxxxxx/T/#u > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > I sent a patch to drop HIGHPTE support on x86 today, see > https://lore.kernel.org/lkml/20241210144945.2325330-9-arnd@xxxxxxxxxx/T/#u > > If that one gets merged, we can merge this one instead of the one > that makes HIGHPTE depend on !PREEMPT_RT, but if we decide against > the x86 change, then we probably don't want this one either. Based on what I have written in 20241211140402.yf7gMExr@xxxxxxxxxxxxx it makes sense. Acked-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Sebastian
