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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91965C46CD2 for ; Wed, 24 Jan 2024 05:46:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 29E4B8D0003; Wed, 24 Jan 2024 00:46:44 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 226BF8D0001; Wed, 24 Jan 2024 00:46:44 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0A1918D0003; Wed, 24 Jan 2024 00:46:44 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id ECF5A8D0001 for ; Wed, 24 Jan 2024 00:46:43 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id C5E51801D5 for ; Wed, 24 Jan 2024 05:46:43 +0000 (UTC) X-FDA: 81713120286.27.5307C3B Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by imf02.hostedemail.com (Postfix) with ESMTP id 71C7980004 for ; Wed, 24 Jan 2024 05:46:41 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=SgqZYUET; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf02.hostedemail.com: domain of aneesh.kumar@kernel.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=aneesh.kumar@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1706075202; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=4ltIJ3M8D37j7XET67H6xkh40PuANTJUydygPc5UBI4=; b=M8TrNRuL1Hv2XhJcJrQ9fb0lfNXs+WOf481ZAiCplhi1CFsIFPToMGjcpVd4U5HPZwNTeX P1PV27tt4lBGqEZOEGikbxuP0n83ipPLAJq2qkTPuLT7bsNowtSizSPXvi7EWF9lBhiNC3 KbrUTLe6SAnNnYqE8heeHkgDDcoMyr0= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=SgqZYUET; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf02.hostedemail.com: domain of aneesh.kumar@kernel.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=aneesh.kumar@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1706075202; a=rsa-sha256; cv=none; b=hJrdA+IQKgPYGxTpCboUyrA9LdCzGRhBnfOipSDQeJeEeVXGzbuTGHYdEoDX72HcIg/tGg QqicRFTIdFpJ7o6HfxosF5KLtK02P7ewoZx1MEKO7a2zY5TYPXNHsG+i8JMa+liEeIi42r CHcKdRSmg3wA85Qqcn7pRM1u57SxVtE= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 6F5B6CE29A9; Wed, 24 Jan 2024 05:46:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75644C433F1; Wed, 24 Jan 2024 05:46:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706075195; bh=LhesHwoZXRdX5jfbi0laKsTDlPHkqd2QNDhd5PA0n64=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=SgqZYUETYp0U/lExF64JKpfQ4QQzjrtotn/ONStmemo8UuEWx22RNGcCPysz/GGdH wF4/0iVnvQm3wM0s4Ag4Pkguroe5zo7K7nKVaDa3YhK1ow6WyrrQ0jGg/jh0nlfdU+ f9jiSYnPlhA+oQTs1xwIrXNokUtNwZ94UcVY9oqXd8lQQbttaFJlpF0H4Hptl0pH0W L6Si/Ez2ZPcSiKG/jTqZNA1RfHBeGdDrwVDOodIiOjh9BxNSAwCbUb8UnpBbsGqMmX Fry6owvnHK5HB/4QPvBt/16sEl5jOidoL18vHxJm0dea3fi94NjlvWmuxijOXq/zBL NkyRrt3sGxNQg== X-Mailer: emacs 29.1 (via feedmail 11-beta-1 I) From: Aneesh Kumar K.V To: David Hildenbrand , Christophe Leroy , Ryan Roberts , "linux-kernel@vger.kernel.org" Cc: "linux-mm@kvack.org" , Andrew Morton , Matthew Wilcox , Russell King , Catalin Marinas , Will Deacon , Dinh Nguyen , Michael Ellerman , Nicholas Piggin , "Naveen N. Rao" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , "David S. Miller" , "linux-arm-kernel@lists.infradead.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-riscv@lists.infradead.org" , "linux-s390@vger.kernel.org" , "sparclinux@vger.kernel.org" Subject: Re: [PATCH v1 01/11] arm/pgtable: define PFN_PTE_SHIFT on arm and arm64 In-Reply-To: <3a970289-a72f-418e-b43c-89f67f0d5283@redhat.com> References: <20240122194200.381241-1-david@redhat.com> <20240122194200.381241-2-david@redhat.com> <46080ac1-7789-499b-b7f3-0231d7bd6de7@redhat.com> <6703b648-10ab-4fea-b7f1-75421319465b@arm.com> <3a970289-a72f-418e-b43c-89f67f0d5283@redhat.com> Date: Wed, 24 Jan 2024 11:16:23 +0530 Message-ID: <87zfwvp9lc.fsf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain X-Rspamd-Queue-Id: 71C7980004 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: nghw3de7mc5csgpy5bnn6o9ky5ee4iba X-HE-Tag: 1706075201-867011 X-HE-Meta: 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 a6IeV2HO FYXrUjRTYUAtKknHXwl9fx46d9J/l2k/THtccvDh0Wmd3dv2brFka20d7xlivHkUfWM/7Fj2oB23+JfmR30XDhheoH+06+FO8kjoOImAIjcvUaDayvNYB1zg9oQYQyQYSn5y6r15zJJ3p9XklpchU9O8PQWBLcM/PEzOV9peMPMaa1x0BE6A+ViligSshc4S8D9M6Lwv5CGl5/mbKoK3rd4Kq7/fOarP/ATAR8Nggaabmf4U7Eiako/ZRNg== 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: List-Subscribe: List-Unsubscribe: David Hildenbrand writes: >>> >>>> If high bits are used for >>>> something else, then we might produce a garbage PTE on overflow, but that >>>> shouldn't really matter I concluded for folio_pte_batch() purposes, we'd not >>>> detect "belongs to this folio batch" either way. >>> >>> Exactly. >>> >>>> >>>> Maybe it's likely cleaner to also have a custom pte_next_pfn() on ppc, I just >>>> hope that we don't lose any other arbitrary PTE bits by doing the pte_pgprot(). >>> >>> I don't see the need for ppc to implement pte_next_pfn(). >> >> Agreed. > > So likely we should then do on top for powerpc (whitespace damage): > > diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c > index a04ae4449a025..549a440ed7f65 100644 > --- a/arch/powerpc/mm/pgtable.c > +++ b/arch/powerpc/mm/pgtable.c > @@ -220,10 +220,7 @@ void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep, > break; > ptep++; > addr += PAGE_SIZE; > - /* > - * increment the pfn. > - */ > - pte = pfn_pte(pte_pfn(pte) + 1, pte_pgprot((pte))); > + pte = pte_next_pfn(pte); > } > } Agreed. -aneesh