From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70230C433E0 for ; Mon, 1 Feb 2021 03:47:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E5E6064E25 for ; Mon, 1 Feb 2021 03:47:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E5E6064E25 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4A2256B006C; Sun, 31 Jan 2021 22:47:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 452206B006E; Sun, 31 Jan 2021 22:47:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 340CD6B0070; Sun, 31 Jan 2021 22:47:25 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0024.hostedemail.com [216.40.44.24]) by kanga.kvack.org (Postfix) with ESMTP id 1D1026B006C for ; Sun, 31 Jan 2021 22:47:25 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D73BE180AD822 for ; Mon, 1 Feb 2021 03:47:24 +0000 (UTC) X-FDA: 77768314008.22.music01_2313a47275bf Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id B577E18038E6F for ; Mon, 1 Feb 2021 03:47:24 +0000 (UTC) X-HE-Tag: music01_2313a47275bf X-Filterd-Recvd-Size: 5858 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Mon, 1 Feb 2021 03:47:24 +0000 (UTC) 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 8A39C1042; Sun, 31 Jan 2021 19:47:23 -0800 (PST) Received: from [10.163.93.126] (unknown [10.163.93.126]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 382673F718; Sun, 31 Jan 2021 19:47:18 -0800 (PST) Subject: Re: [PATCH 2/2] arm64/mm: Reorganize pfn_valid() To: David Hildenbrand , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Catalin Marinas , Will Deacon , Ard Biesheuvel , Mark Rutland , James Morse , Robin Murphy , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Dan Williams , Mike Rapoport References: <1611905986-20155-1-git-send-email-anshuman.khandual@arm.com> <1611905986-20155-3-git-send-email-anshuman.khandual@arm.com> <9050792c-feba-1b72-681e-ebc28fc1fcc5@redhat.com> From: Anshuman Khandual Message-ID: <681dd64b-e10a-1ec8-abad-d3eee0ddfa45@arm.com> Date: Mon, 1 Feb 2021 09:17:47 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <9050792c-feba-1b72-681e-ebc28fc1fcc5@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 1/29/21 3:37 PM, David Hildenbrand wrote: > On 29.01.21 08:39, Anshuman Khandual wrote: >> There are multiple instances of pfn_to_section_nr() and __pfn_to_secti= on() >> when CONFIG_SPARSEMEM is enabled. This can be just optimized if the me= mory >> section is fetched earlier. Hence bifurcate pfn_valid() into two diffe= rent >> definitions depending on whether CONFIG_SPARSEMEM is enabled. Also rep= lace >> the open coded pfn <--> addr conversion with __[pfn|phys]_to_[phys|pfn= ](). >> This does not cause any functional change. >> >> Cc: Catalin Marinas >> Cc: Will Deacon >> Cc: Ard Biesheuvel >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Anshuman Khandual >> --- >> =C2=A0 arch/arm64/mm/init.c | 38 +++++++++++++++++++++++++++++++------= - >> =C2=A0 1 file changed, 31 insertions(+), 7 deletions(-) >> >> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c >> index 1141075e4d53..09adca90c57a 100644 >> --- a/arch/arm64/mm/init.c >> +++ b/arch/arm64/mm/init.c >> @@ -217,18 +217,25 @@ static void __init zone_sizes_init(unsigned long= min, unsigned long max) >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 free_area_init(max_zone_pfns); >> =C2=A0 } >> =C2=A0 +#ifdef CONFIG_SPARSEMEM >> =C2=A0 int pfn_valid(unsigned long pfn) >> =C2=A0 { >> -=C2=A0=C2=A0=C2=A0 phys_addr_t addr =3D pfn << PAGE_SHIFT; >> +=C2=A0=C2=A0=C2=A0 struct mem_section *ms =3D __pfn_to_section(pfn); >> +=C2=A0=C2=A0=C2=A0 phys_addr_t addr =3D __pfn_to_phys(pfn); >=20 > I'd just use PFN_PHYS() here, which is more frequently used in the kern= el. Sure, will replace. >=20 >> =C2=A0 -=C2=A0=C2=A0=C2=A0 if ((addr >> PAGE_SHIFT) !=3D pfn) >> +=C2=A0=C2=A0=C2=A0 /* >> +=C2=A0=C2=A0=C2=A0=C2=A0 * Ensure the upper PAGE_SHIFT bits are clear= in the >> +=C2=A0=C2=A0=C2=A0=C2=A0 * pfn. Else it might lead to false positives= when >> +=C2=A0=C2=A0=C2=A0=C2=A0 * some of the upper bits are set, but the lo= wer bits >> +=C2=A0=C2=A0=C2=A0=C2=A0 * match a valid pfn. >> +=C2=A0=C2=A0=C2=A0=C2=A0 */ >> +=C2=A0=C2=A0=C2=A0 if (__phys_to_pfn(addr) !=3D pfn) >=20 > and here PHYS_PFN(). Comment is helpful. :) Sure, will replace. >=20 >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return 0; >> =C2=A0 -#ifdef CONFIG_SPARSEMEM >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 if (pfn_to_section_nr(pfn) >=3D NR_MEM_= SECTIONS) >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return 0; >> =C2=A0 -=C2=A0=C2=A0=C2=A0 if (!valid_section(__pfn_to_section(pfn))) >> +=C2=A0=C2=A0=C2=A0 if (!valid_section(ms)) >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return 0; >> =C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 /* >> @@ -240,11 +247,28 @@ int pfn_valid(unsigned long pfn) >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * memory sections covering all of= hotplug memory including >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * both normal and ZONE_DEVICE bas= ed. >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 */ >> -=C2=A0=C2=A0=C2=A0 if (!early_section(__pfn_to_section(pfn))) >> -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return pfn_section_valid(_= _pfn_to_section(pfn), pfn); >> -#endif >> +=C2=A0=C2=A0=C2=A0 if (!early_section(ms)) >> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return pfn_section_valid(m= s, pfn); >> + >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return memblock_is_map_memory(addr); >> =C2=A0 } >> +#else >> +int pfn_valid(unsigned long pfn) >> +{ >> +=C2=A0=C2=A0=C2=A0 phys_addr_t addr =3D __pfn_to_phys(pfn); >> + >> +=C2=A0=C2=A0=C2=A0 /* >> +=C2=A0=C2=A0=C2=A0=C2=A0 * Ensure the upper PAGE_SHIFT bits are clear= in the >> +=C2=A0=C2=A0=C2=A0=C2=A0 * pfn. Else it might lead to false positives= when >> +=C2=A0=C2=A0=C2=A0=C2=A0 * some of the upper bits are set, but the lo= wer bits >> +=C2=A0=C2=A0=C2=A0=C2=A0 * match a valid pfn. >> +=C2=A0=C2=A0=C2=A0=C2=A0 */ >> +=C2=A0=C2=A0=C2=A0 if (__phys_to_pfn(addr) !=3D pfn) >> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return 0; >> + >> +=C2=A0=C2=A0=C2=A0 return memblock_is_map_memory(addr); >> +} >=20 >=20 > I think you can avoid duplicating the code by doing something like: Right and also this looks more compact as well. Initially though about it but then was apprehensive about the style in #ifdef { } #endif code block inside the function. After this change, the resulting patch also clears checkpatch.pl test. Will do the change. >=20 >=20 > phys_addr_t addr =3D PFN_PHYS(pfn); >=20 > if (PHYS_PFN(addr) !=3D pfn) > =C2=A0=C2=A0=C2=A0=C2=A0return 0; >=20 > #ifdef CONFIG_SPARSEMEM > { > =C2=A0=C2=A0=C2=A0=C2=A0struct mem_section *ms =3D __pfn_to_section(pfn= ); >=20 > =C2=A0=C2=A0=C2=A0=C2=A0if (!valid_section(ms)) > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return 0; > =C2=A0=C2=A0=C2=A0=C2=A0if (!early_section(ms)) > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return pfn_section_valid(ms,= pfn); > } > #endif > return memblock_is_map_memory(addr); >=20