On Thu, 2023-06-22 at 06:37 -0700, Dave Hansen wrote: > On 6/22/23 06:14, ypodemsk@xxxxxxxxxx wrote: > > I will send a new version with the local variable as you suggested > > soon. > > As for the config name, what about CONFIG_ARCH_HAS_MM_CPUMASK? > > The confusing part about that name is that mm_cpumask() and > mm->cpu_bitmap[] are defined unconditionally. So, they're *around* > unconditionally but just aren't updated. > I think your right about the config name, How about the CONFIG_ARCH_USE_MM_CPUMASK? This has the right semantic as these archs use the cpumask field of the mm struct. > BTW, it would also be nice to have _some_ kind of data behind this > patch. > > Fewer IPIs are better I guess, but it would still be nice if you > could say: > > Before this patch, /proc/interrupts showed 123 IPIs/hour for an > isolated CPU. After the approach here, it was 0. > > ... or something. This is part of an ongoing effort to remove IPIs and this one was found via code inspection.