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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C301AC3600C for ; Thu, 3 Apr 2025 07:17:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version:Content-Type: References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5h4NwVrra0xZ8kyyCfhI/I2E6X0Ur04USQwYLb++ZOY=; b=V64ZcTUSW8NrOgW4cNhjE3YXoF b+fVix7bXQcwKWSlHnlswJB397eCmvD93eqzaRPmivSH/uPLk1oXwujOHdVG9H4o9oxaq0izxSWHB AzukKng+QqhDuFWInNSWExL2unIKtCzbzF3e8xyD1Grgj1DUC3IN8vYezqtmQr0tHntb1WvKc8GRO G625gGqXXobLJDw8HpciIYBE4jHLCvIbFcJQqQCrztK3/7PiOi89ZtAKyaWJAPFZFAK0pHV0lp88B gVUODIcdwzz0i1ecPf7fzPul/DhS4u1BR8W8hUvIAuR6x1pjQJ6tuh5g/MnT78DsfsW4K6ODzZaT0 RtdEjrSA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1u0EpQ-000000084jk-3u1p; Thu, 03 Apr 2025 07:17:32 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1u0Eng-000000084Lc-2eAH for linux-arm-kernel@bombadil.infradead.org; Thu, 03 Apr 2025 07:15:44 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=MIME-Version:Content-Type:References: In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=5h4NwVrra0xZ8kyyCfhI/I2E6X0Ur04USQwYLb++ZOY=; b=i31GV1sm3Di5fOUBiUTACQWE1D r5EjSbLGEFN3XLYdVANOEk6w0vjlVozRoH0PtK0kqDwT4yhvetCO/5RTg4/iLyh4VPl+Yywa8+Y/v Jqapk1k0PjSanxCB4ZzCcgDEfbmIUjJCpwX0gWKDE+BRNMyXcab2sOX+hsdQjvcFGyKw0Uh/xWZaB Tj2ohAtUsjFa3VwisWzuC3SA2HvxvE/edWGi1RoA74e/xBuxYTLDx+UcKOXkuqZ6tUzqJ/j4B7itk lZIbHMspZb9WHFqImH+Qs3ma7uWhRRxld7LfLK5k63Ii0IKd9Hu/INSoYQyhtjS//wuB4QwtLPlhU ZHYcRNbA==; Received: from [172.31.31.145] (helo=u09cd745991455d.ant.amazon.com) by desiato.infradead.org with esmtpsa (Exim 4.98.1 #2 (Red Hat Linux)) id 1u0End-000000079CN-1E3r; Thu, 03 Apr 2025 07:15:41 +0000 Message-ID: <380d9bff359150f67ca6e0468f99ee746c1abdea.camel@infradead.org> Subject: Re: [RFC PATCH 3/3] mm: Implement for_each_valid_pfn() for CONFIG_SPARSEMEM From: David Woodhouse To: Mike Rapoport Cc: Andrew Morton , "Sauerwein, David" , Anshuman Khandual , Ard Biesheuvel , Catalin Marinas , David Hildenbrand , Marc Zyngier , Mark Rutland , Mike Rapoport , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Date: Thu, 03 Apr 2025 08:15:41 +0100 In-Reply-To: References: <20250402201841.3245371-1-dwmw2@infradead.org> <20250402201841.3245371-3-dwmw2@infradead.org> Content-Type: multipart/signed; micalg="sha-256"; protocol="application/pkcs7-signature"; boundary="=-K4I0nADpgjkH/E9CYStz" User-Agent: Evolution 3.52.3-0ubuntu1 MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by desiato.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --=-K4I0nADpgjkH/E9CYStz Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2025-04-03 at 08:07 +0100, David Woodhouse wrote: >=20 > I'll see if I can make it neater. I may drop the 'ret' variable > completely and just turn the match clause into unlock-and-return-true. > I *like* having a single unlock site. But I think I like simpler loop > code more than that. That's better (IMO). And I note that pfn_valid() already doesn't follow the modern fetish for having only one unlock site even when it makes the surrounding code more complex to do so. static inline bool first_valid_pfn(unsigned long *p_pfn) { unsigned long pfn =3D *p_pfn; unsigned long nr =3D pfn_to_section_nr(pfn); struct mem_section *ms; rcu_read_lock_sched(); while (nr <=3D __highest_present_section_nr) { ms =3D __pfn_to_section(pfn); if (valid_section(ms) && (early_section(ms) || pfn_section_first_valid(ms, &pfn))) { *p_pfn =3D pfn; rcu_read_unlock_sched(); return true; } /* Nothing left in this section? Skip to next section */ nr++; pfn =3D section_nr_to_pfn(nr); } rcu_read_unlock_sched(); return false; } --=-K4I0nADpgjkH/E9CYStz Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCD9Aw ggSOMIIDdqADAgECAhAOmiw0ECVD4cWj5DqVrT9PMA0GCSqGSIb3DQEBCwUAMGUxCzAJBgNVBAYT AlVTMRUwEwYDVQQKEwxEaWdpQ2VydCBJbmMxGTAXBgNVBAsTEHd3dy5kaWdpY2VydC5jb20xJDAi BgNVBAMTG0RpZ2lDZXJ0IEFzc3VyZWQgSUQgUm9vdCBDQTAeFw0yNDAxMzAwMDAwMDBaFw0zMTEx MDkyMzU5NTlaMEExCzAJBgNVBAYTAkFVMRAwDgYDVQQKEwdWZXJva2V5MSAwHgYDVQQDExdWZXJv a2V5IFNlY3VyZSBFbWFpbCBHMjCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAMjvgLKj jfhCFqxYyRiW8g3cNFAvltDbK5AzcOaR7yVzVGadr4YcCVxjKrEJOgi7WEOH8rUgCNB5cTD8N/Et GfZI+LGqSv0YtNa54T9D1AWJy08ZKkWvfGGIXN9UFAPMJ6OLLH/UUEgFa+7KlrEvMUupDFGnnR06 aDJAwtycb8yXtILj+TvfhLFhafxroXrflspavejQkEiHjNjtHnwbZ+o43g0/yxjwnarGI3kgcak7 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