Subject: Re: [PATCH] powerpc/64s/radix: tlb do not flush on page size when fullmm

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Wed, 25 Jul 2018 19:47:29 +0530

Nicholas Piggin <[email-masked]> writes:

> When the mm is being torn down there will be a full PID flush so
> there is no need to flush the TLB on page size changes.

and that tlb flush is PID flush since tlb->fulmm is set? So this avoids
multiple PID tlb flush.

Reviewed-by: Aneesh Kumar K.V <[email-masked]>

>
> Signed-off-by: Nicholas Piggin <[email-masked]>
> ---
>  arch/powerpc/include/asm/tlb.h | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/tlb.h b/arch/powerpc/include/asm/tlb.h
> index 5d3107f2b014..d1b3dc4a6a0a 100644
> --- a/arch/powerpc/include/asm/tlb.h
> +++ b/arch/powerpc/include/asm/tlb.h
> @@ -84,6 +84,9 @@ static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
>  static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb,
>  						     unsigned int page_size)
>  {
> +	if (tlb->fullmm)
> +		return;
> +
>  	if (!tlb->page_size)
>  		tlb->page_size = page_size;
>  	else if (tlb->page_size != page_size) {
> -- 
> 2.17.0