On 2024-04-17 Andreas Dilger wrote: > On Apr 16, 2024, at 4:36 PM, Nam Cao <namcao@xxxxxxxxxxxxx> wrote: > > However, I am confused about one thing: doesn't this make one page of > > physical memory inaccessible? > > > > Is it better to solve this by setting max_low_pfn instead? Then at > > least the page is still accessible as high memory. > > Is that one page of memory really worthwhile to preserve? Better to > have a simple solution that works, Good point. > maybe even mapping that page > read-only so that any code which tries to dereference an ERR_PTR > address immediately gets a fault? Not sure about this part: it doesn't really fix the problem, just changes from subtle crashes into page faults. Let me send a patch to reserve the page: simple and works for all architectures. Best regards, Nam