On Jul 7, 2022, at 11:59 PM, Barry Song <21cnbao@xxxxxxxxx> wrote: >> The cpumask_empty() is indeed just another memory access, which is most >> likely ok. But wouldn’t adding something like CONFIG_ARCH_HAS_MM_CPUMASK >> make the code simpler and (slightly, certainly slightly) more performant? > > Yep. good suggestion, Nadav. So the code will be as below, right? Hmmm… Although it is likely to work (because only x86 and arm would use this batch flushing), I think that for consistency ARCH_HAS_MM_CPUMASK should be correct for all architectures. Is it really only x86 that has mm_cpumask()?