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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 A42E9C83007 for ; Tue, 28 Apr 2020 19:45:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8481520BED for ; Tue, 28 Apr 2020 19:45:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="X097XksK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729232AbgD1TpI (ORCPT ); Tue, 28 Apr 2020 15:45:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1728703AbgD1TpH (ORCPT ); Tue, 28 Apr 2020 15:45:07 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B720AC03C1AB; Tue, 28 Apr 2020 12:45:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=ozJ4/VCCoOCPsRdSc3NikpEPmevttfRVGSWHfGtgyPo=; b=X097XksKF4UJYy1M1UQSEzc/TX wSx6mHzP0Pg7Lyy3l4oJPeFr3jUWzn18Hmdo73qxJ84N80PzFceLS+XkuPpVpIyrEczeLGCljKXCA LstVM5ix6YN91UPAre63NSEEuYBVMgjie7FrTjktpVI1GLc3HIEbGm4sDrFKtT0/OtRqaOd9Ycyx2 ZBWbA9d/XkyEioVunlmS82vG+CkUMbDhPi3Tedd2bqVzuc+GclRHpMZxRPwM8w2mZv2BIRUK/XCXd Jmj70qYwEAKbJajKBWiqFVA6zP3P6fux5euO+6RsMsEurvYdTCB3wYrmb6wKKcvG8lbjB+uo/95EP /2EgeWCg==; 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 Cc: "Matthew Wilcox (Oracle)" , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Will Deacon , Catalin Marinas , Russell King , Geert Uytterhoeven , linux-m68k@lists.linux-m68k.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 Content-Transfer-Encoding: 8bit Sender: linux-m68k-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.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) --- 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 */ -- 2.26.2