Re: [PATCH v2 2/2] mm/mmu_gather: send tlb_remove_table_smp_sync IPI only to MM CPUs

From: Dave Hansen
Date: Thu Jun 22 2023 - 09:38:03 EST


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.

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.