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 E0E2D212B39 for ; Thu, 13 Feb 2025 09:10:03 +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=1739437806; cv=none; b=dvheWjuOcEoMMO2g6DVd6HsvoLu/NL+Q3ZBdCPhMySQWw8TdjoMooaADAePnFTv5hcUsVKeSXT+wCxwfVUuTRAPYB3xUFIhgYidYeuxwcO+D+oi+Bv3QXnfyDW37nOCyOgEs24JzcLMc1IjHjn2t9MeWEy8owb05o5S9fI4khMw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739437806; c=relaxed/simple; bh=/SlBUoD84XdaAKAKmYrfM34fE048jnhVWBnMBDvOjn8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=MkAkUxzVqw3fA2v9yvN9YKrr8vOp5dDFtlxtBwhCp1EAvs3C0XG+FsezMTV64SUcoldS6+nKApQXjNimBFRbc/CVFZn8yvNDge3vUxteoX5O79oiBQLoRnTBMB5kq9TeOiqzWqZIGNkTsCrLaPSJ/H0FoCR7GCNsXxWbvktVce0= 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 A4B4716F3; Thu, 13 Feb 2025 01:10:17 -0800 (PST) Received: from [10.57.81.93] (unknown [10.57.81.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5596D3F58B; Thu, 13 Feb 2025 01:09:54 -0800 (PST) Message-ID: Date: Thu, 13 Feb 2025 09:09:52 +0000 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 12/16] arm64/mm: Support huge pte-mapped pages in vmap Content-Language: en-GB To: Anshuman Khandual , Catalin Marinas , Will Deacon , Muchun Song , Pasha Tatashin , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , Mark Rutland , Ard Biesheuvel , Dev Jain , Alexandre Ghiti , Steve Capper , Kevin Brodsky Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20250205151003.88959-1-ryan.roberts@arm.com> <20250205151003.88959-13-ryan.roberts@arm.com> <9a0d3009-18fc-4b53-941a-b6d830fce36a@arm.com> <21da59a8-165d-4423-a00d-d5859f42ec11@arm.com> <0dd74f57-902a-4a6d-9f77-31963b5953d1@arm.com> From: Ryan Roberts In-Reply-To: <0dd74f57-902a-4a6d-9f77-31963b5953d1@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit >>>> +#define arch_vmap_pte_range_map_size arch_vmap_pte_range_map_size >>>> +static inline unsigned long arch_vmap_pte_range_map_size(unsigned long addr, >>>> + unsigned long end, u64 pfn, >>>> + unsigned int max_page_shift) >>>> +{ >>>> + if (max_page_shift < CONT_PTE_SHIFT) >>>> + return PAGE_SIZE; >>>> + >>>> + if (end - addr < CONT_PTE_SIZE) >>>> + return PAGE_SIZE; >>>> + >>>> + if (!IS_ALIGNED(addr, CONT_PTE_SIZE)) >>>> + return PAGE_SIZE; >>>> + >>>> + if (!IS_ALIGNED(PFN_PHYS(pfn), CONT_PTE_SIZE)) >>>> + return PAGE_SIZE; >>>> + >>>> + return CONT_PTE_SIZE; >>> >>> A small nit: >>> >>> Should the rationale behind picking CONT_PTE_SIZE be added here as an in code >>> comment or something in the function - just to make things bit clear. >> >> I'm not sure what other size we would pick? > > The suggestion was to add a small comment in the above helper function explaining > the rationale for various conditions in there while returning either PAGE_SIZE or > CONT_PTE_SIZE to improve readability etc. OK I've added the following: /* * If the block is at least CONT_PTE_SIZE in size, and is naturally * aligned in both virtual and physical space, then we can pte-map the * block using the PTE_CONT bit for more efficient use of the TLB. */ Thanks, Ryan