From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 905EF2557A for ; Wed, 24 Sep 2025 08:57:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758704271; cv=none; b=KLRg279ZHK29FDw/zNKyVOcI3sO8WXUBlAQKFoFdqmVj41l+yQrQpDv3pfY3wUSCcIvO5a3jiR2KoswAkV7fVRmn0wU+kotNxaLvMS/xOFHNi8BkrdHUOHM/P3OsKcutWvCuIspiplZrTVeV6IDjVf1wkPhNvvEIh0Wx8IWmVGw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758704271; c=relaxed/simple; bh=cXGV0okpqUEWPwKXCfr2tuHmvSgWqSUR7ptaiibITVY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=giyuvDN8bVT0hMMOlZrSHwgzS7d9nqa5V+EboSu0Ojq7ZKDhdnufEb+dBOS7GK2Hy835EDI+Umq5Y80xYUDjoo8y7BKAVScL5MaLPWVGWpjQYxRjRxMb8v7TpvtBFV4AoyEbSJFypg6GVrNdBNxgbmXjkVgDMaR5ZRXwZbIvM0k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EC73C106F; Wed, 24 Sep 2025 01:57:40 -0700 (PDT) Received: from [10.164.18.52] (MacBook-Pro.blr.arm.com [10.164.18.52]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5FBC53F5A1; Wed, 24 Sep 2025 01:57:46 -0700 (PDT) Message-ID: Date: Wed, 24 Sep 2025 14:27:43 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1] mm: convert folio_page() back to a macro To: David Hildenbrand , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko References: <20250923140058.2020023-1-david@redhat.com> Content-Language: en-US From: Dev Jain In-Reply-To: <20250923140058.2020023-1-david@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 23/09/25 7:30 pm, David Hildenbrand wrote: > In commit 73b3294b1152 ("mm: simplify folio_page() and folio_page_idx()") > we converted folio_page() into a static inline function. However > briefly afterwards in commit a847b17009ec ("mm: constify highmem related > functions for improved const-correctness") we had to add some nasty > const-away casting to make the compiler happy when checking const > correctness. > > So let's just convert it back to a simple macro so the compiler can > check const correctness properly. There is the alternative of > using a _Generic() similar to page_folio(), but there is not a lot of > benefit compared to just using a simple macro. > > Cc: Andrew Morton > Cc: Lorenzo Stoakes > Cc: "Liam R. Howlett" > Cc: Vlastimil Babka > Cc: Mike Rapoport > Cc: Suren Baghdasaryan > Cc: Michal Hocko > Signed-off-by: David Hildenbrand > --- Reviewed-by: Dev Jain