From patchwork Tue Apr 28 19:44:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11515431 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A5A3A912 for ; Tue, 28 Apr 2020 19:47:10 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 75A7921707 for ; Tue, 28 Apr 2020 19:47:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Zq2BTN+L" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 75A7921707 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=I6lGPwZnbWU4QpyWdTNl8ayLtdwktN9d+792WGwSn8k=; b=Zq2BTN+LqHTj+2 vzUY7XAmo44U1yq/URL5hOFD64hKxChok6YP92Z4seQEKdcsAjXd2GcErg8HRnrjv27jVA1eNsV/d /F4jtsyC4tqyQZ9Emr17x59oG8vtuooswL0IAhOCalaPEuc6cOSkkcblre21vLjFcxBGdGyEQrUBp y7v/O3t7eqqoTIaxQp1H95z1ZTt8W5P8ShYLRtvXa58PZIQqYLGNFPtQNOWXiDMgJ4o1LlA01l5GN AWe7Z3KZHnVO042DZUfWWoR/nvY3MceLzhrh3desIPHDaX+5osM7m88DXyF0TqtGAP1iq/o9Q2b5v EqSs1tnGBlAzzOUu+eqw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jTWC8-0001r7-BK; Tue, 28 Apr 2020 19:47:04 +0000 Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jTW9y-0005uQ-TN; Tue, 28 Apr 2020 19:44:50 +0000 From: Matthew Wilcox To: linux-mm@kvack.org Subject: [PATCH 1/7] mm: Document x86 uses a linked list of pgds Date: Tue, 28 Apr 2020 12:44:43 -0700 Message-Id: <20200428194449.22615-2-willy@infradead.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200428194449.22615-1-willy@infradead.org> References: <20200428194449.22615-1-willy@infradead.org> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Catalin Marinas , linux-kernel@vger.kernel.org, "Matthew Wilcox \(Oracle\)" , Russell King , linux-m68k@lists.linux-m68k.org, Geert Uytterhoeven , Will Deacon , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: "Matthew Wilcox (Oracle)" x86 uses page->lru of the pages used for pgds, but that's not immediately obvious to anyone looking to make changes. Add a struct list_head to the union so it's clearly in use for pgds. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Ira Weiny --- include/linux/mm_types.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 4aba6c0c2ba8..9bb34e2cd5a5 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -142,8 +142,13 @@ struct page { struct list_head deferred_list; }; struct { /* Page table pages */ - unsigned long _pt_pad_1; /* compound_head */ - pgtable_t pmd_huge_pte; /* protected by page->ptl */ + union { + struct list_head pgd_list; /* x86 */ + struct { + unsigned long _pt_pad_1; + pgtable_t pmd_huge_pte; + }; + }; unsigned long _pt_pad_2; /* mapping */ union { struct mm_struct *pt_mm; /* x86 pgds only */