From patchwork Thu Jun 22 20:57:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vishal Moola X-Patchwork-Id: 13289745 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 E269DC001DF for ; Thu, 22 Jun 2023 20:58:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8ww+EpQN8E61o3DKEFsi2cgwsFHLpE5HM1RjP3uhVTw=; b=Us0rpxsmHev9pg 3RDpSj0cfaeHbtQyNq3+bCk5Q13DWw4VtU8dq9K8l4M8m/gLZldR3GXoZFs09oNxRJJxXZ5tjEWJM ipbvD+jRXZCY0rEzeIOQOV16DyW0J+eQXNlv/p/3a6fJ1NlLRMsteKAl448bkdrRCYXnJTGKlQEHQ oYXQuKY0Fa1iY/vSlZwj7lG704ykyJWN15anO5neW0GrO+/Ib4RdV+T8Z1WZmoz+sJizo2NH9I4Au MEi4lLCGAaikqPN4DH2BYv+X4o5/NHKQO2BE9CZXLtiI25L9sLu1HNx/LElepWQbSi8duSeutE2e0 SPhwJ8nzN4t2Fb88H0EA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qCRNr-001hv7-0y; Thu, 22 Jun 2023 20:58:27 +0000 Received: from mail-yb1-xb36.google.com ([2607:f8b0:4864:20::b36]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qCRNT-001hYB-0k; Thu, 22 Jun 2023 20:58:05 +0000 Received: by mail-yb1-xb36.google.com with SMTP id 3f1490d57ef6-bcd0226607bso1693157276.1; Thu, 22 Jun 2023 13:58:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687467482; x=1690059482; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=g10wkISUfh+NWh/zmhT9FX+m3ZttfvdTUqPKBonJP24=; b=pU1rNku+EwfuvvAUFkFumH3vBy2yB8eY8b9rmQMddlJoc9QhOnRcokyjWDtIUPPy9P MyE7phtpnefNxvysKqFF1dCChREaY4VAw7Hj9WJFlZFrzpk6eifBId3wubz0Vyh/S2pn 8/Y3zkVGHHKKYxzZzu8HCxLQTltPQvJHitS9QsbrsAUgPjueiuuK933isxWF/RQdLHvt zcy+Qct09qmvfH+KRctZzkT+vvZGDQDyiysBgsbHpUxND18HRJm9vVFEK6S0KHOtgU7u IRCWYGiDuX3Hydg/OjrZHIGz2lGmohOF8cCd3deLunhE1oH3PJ2GTuP2PJzlmW5OQRrp EAKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687467482; x=1690059482; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=g10wkISUfh+NWh/zmhT9FX+m3ZttfvdTUqPKBonJP24=; b=KYkInX4AuAvdHIuPUEtPvzhtTg2Wanv/Gd+c5dIudbVDtd4miVyuCPsQZ6eViZLGcn leifwVatPUTSJmkjIx4MAokVI/PUZIaO2hxxRVjjGZUtsZy/9jz+DET92xYs012DWjWt g1yov5F1tpKDJGJif5NH+QfpTyHFz/PXq5DAoJRujPboSJ6zB5NFhp146GJNAqRe1pzT wj5kDCt9X8OnRny+5f4KJuP+Z5RNmt+ToksNmb8U2sqnxBJ1unb4VltuOt6ihTullD3a /5+caN9k0yoIVxG0o5MA2uEERCQGKwN4Nc7wu7LTvnPkRIzQZuNv1pYl2mFy6xo6NKZt FosQ== X-Gm-Message-State: AC+VfDxIeznTKtq16hnPssoeuEUH2kE8El4sYjtKI/RqeW+OgPQzTMvp mFsqVIqUMwMrbL7QdRygeZk= X-Google-Smtp-Source: ACHHUZ77fWcfFpcqNU9K3kqcEPsqSpbWa/fmZ/3pFZFyzvd1rtc51te7WicHxIwYc2YzOzHNnZEaEA== X-Received: by 2002:a25:2f85:0:b0:bd5:eeb4:55be with SMTP id v127-20020a252f85000000b00bd5eeb455bemr19092596ybv.0.1687467482307; Thu, 22 Jun 2023 13:58:02 -0700 (PDT) Received: from unknowna0e70b2ca394.attlocal.net ([2600:1700:2f7d:1800::36]) by smtp.googlemail.com with ESMTPSA id d18-20020a5b0c52000000b00bc501a1b062sm1684937ybr.42.2023.06.22.13.58.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Jun 2023 13:58:02 -0700 (PDT) From: "Vishal Moola (Oracle)" To: Andrew Morton , Matthew Wilcox Cc: linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-openrisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, xen-devel@lists.xenproject.org, kvm@vger.kernel.org, Hugh Dickins , "Vishal Moola (Oracle)" , Mike Rapoport Subject: [PATCH v5 03/33] pgtable: Create struct ptdesc Date: Thu, 22 Jun 2023 13:57:15 -0700 Message-Id: <20230622205745.79707-4-vishal.moola@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230622205745.79707-1-vishal.moola@gmail.com> References: <20230622205745.79707-1-vishal.moola@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230622_135803_305630_9CCA79C4 X-CRM114-Status: GOOD ( 11.69 ) 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 Currently, page table information is stored within struct page. As part of simplifying struct page, create struct ptdesc for page table information. Signed-off-by: Vishal Moola (Oracle) Acked-by: Mike Rapoport (IBM) --- include/linux/pgtable.h | 68 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 5063b482e34f..d46cb709ce08 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -987,6 +987,74 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma, #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */ #endif /* CONFIG_MMU */ + +/** + * struct ptdesc - Memory descriptor for page tables. + * @__page_flags: Same as page flags. Unused for page tables. + * @pt_rcu_head: For freeing page table pages. + * @pt_list: List of used page tables. Used for s390 and x86. + * @_pt_pad_1: Padding that aliases with page's compound head. + * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs. + * @_pt_s390_gaddr: Aliases with page's mapping. Used for s390 gmap only. + * @pt_mm: Used for x86 pgds. + * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only. + * @ptl: Lock for the page table. + * @__page_type: Same as page->page_type. Unused for page tables. + * @_refcount: Same as page refcount. Used for s390 page tables. + * @pt_memcg_data: Memcg data. Tracked for page tables here. + * + * This struct overlays struct page for now. Do not modify without a good + * understanding of the issues. + */ +struct ptdesc { + unsigned long __page_flags; + + union { + struct rcu_head pt_rcu_head; + struct list_head pt_list; + struct { + unsigned long _pt_pad_1; + pgtable_t pmd_huge_pte; + }; + }; + unsigned long _pt_s390_gaddr; + + union { + struct mm_struct *pt_mm; + atomic_t pt_frag_refcount; + }; + + union { + unsigned long _pt_pad_2; +#if ALLOC_SPLIT_PTLOCKS + spinlock_t *ptl; +#else + spinlock_t ptl; +#endif + }; + unsigned int __page_type; + atomic_t _refcount; +#ifdef CONFIG_MEMCG + unsigned long pt_memcg_data; +#endif +}; + +#define TABLE_MATCH(pg, pt) \ + static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt)) +TABLE_MATCH(flags, __page_flags); +TABLE_MATCH(compound_head, pt_list); +TABLE_MATCH(compound_head, _pt_pad_1); +TABLE_MATCH(pmd_huge_pte, pmd_huge_pte); +TABLE_MATCH(mapping, _pt_s390_gaddr); +TABLE_MATCH(pt_mm, pt_mm); +TABLE_MATCH(ptl, ptl); +TABLE_MATCH(rcu_head, pt_rcu_head); +#ifdef CONFIG_MEMCG +TABLE_MATCH(memcg_data, pt_memcg_data); +#endif +#undef TABLE_MATCH +static_assert(sizeof(struct ptdesc) <= sizeof(struct page)); + /* * No-op macros that just return the current protection value. Defined here * because these macros can be used even if CONFIG_MMU is not defined.