Re: [PATCH v3 4/4] arm64: support batched/deferred tlb shootdown during page reclamation

[Anshuman Khandual]

On 8/22/22 13:51, Yicong Yang wrote:
> +static inline void arch_tlbbatch_add_mm(struct arch_tlbflush_unmap_batch *batch,
> +					struct mm_struct *mm,
> +					unsigned long uaddr)
> +{
> +	__flush_tlb_page_nosync(mm, uaddr);
> +}
> +
> +static inline void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
> +{
> +	dsb(ish);
> +}

Just wondering if arch_tlbbatch_add_mm() could also detect continuous mapping
TLB invalidation requests on a given mm and try to generate a range based TLB
invalidation such as flush_tlb_range().

struct arch_tlbflush_unmap_batch via task->tlb_ubc->arch can track continuous
ranges while being queued up via arch_tlbbatch_add_mm(), any range formed can
later be flushed in subsequent arch_tlbbatch_flush() ?

OR

It might not be worth the effort and complexity, in comparison to performance
improvement, TLB range flush brings in ?