Received-SPF: pass (google.com: domain of linux-kernel+bounces-81214-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
From: Michael Ellerman <mpe@ellerman.id.au>
To: Kunwu Chan <chentao@kylinos.cn>, npiggin@gmail.com,
 christophe.leroy@csgroup.eu, aneesh.kumar@kernel.org,
 naveen.n.rao@linux.ibm.com
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Kunwu Chan
 <chentao@kylinos.cn>
Subject: Re: [PATCH] powerpc/mm: Code cleanup for __hash_page_thp
In-Reply-To: <20240125092624.537564-1-chentao@kylinos.cn>
References: <20240125092624.537564-1-chentao@kylinos.cn>
Date: Mon, 26 Feb 2024 21:49:23 +1100
Message-ID: <87h6hva4b0.fsf@mail.lhotse>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain

Kunwu Chan <chentao@kylinos.cn> writes:
> This part was commented from commit 6d492ecc6489
> ("powerpc/THP: Add code to handle HPTE faults for hugepages")
> in about 11 years before.
>
> If there are no plans to enable this part code in the future,
> we can remove this dead code.

I agree the code can go. But I'd like it to be replaced with a comment
explaining what the dead code was trying to say.

cheers

> diff --git a/arch/powerpc/mm/book3s64/hash_hugepage.c b/arch/powerpc/mm/book3s64/hash_hugepage.c
> index c0fabe6c5a12..127a3a2c174b 100644
> --- a/arch/powerpc/mm/book3s64/hash_hugepage.c
> +++ b/arch/powerpc/mm/book3s64/hash_hugepage.c
> @@ -59,16 +59,6 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
>  
>  	rflags = htab_convert_pte_flags(new_pmd, flags);
>  
> -#if 0
> -	if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
> -
> -		/*
> -		 * No CPU has hugepages but lacks no execute, so we
> -		 * don't need to worry about that case
> -		 */
> -		rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
> -	}
> -#endif
>  	/*
>  	 * Find the slot index details for this ea, using base page size.
>  	 */
> -- 
> 2.39.2