From patchwork Tue Apr 28 19:44:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11515401 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 DDDD592C for ; Tue, 28 Apr 2020 19:44:58 +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 BBDEC21707 for ; Tue, 28 Apr 2020 19:44:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="KkhfBmon" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BBDEC21707 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=WyCPRCMXlM3JGsfvK0faajRz0F+TLpNXvO2E8WFnQK0=; b=KkhfBmontQUNmo qRTZE64YRjzUeno1plmSXJamj5vynHX6eRjdZ139dYRAHmG2I8yRNQg/MY1GW4kCXeDkLEFykAsLy O0HQcL/CDvPgumh8+XWJcTLsRfsBASZBfjqUSYOmarxMzS8BnJQGaN+6ked1rfxDVTh1/rcVBZE3I T/RdcxU2laUGa9m/5PuryJJ9G3ZpGxeXa8CWwMN1CNem6etQZ7ZOcsge/GvBnEB1oB8fBe9fJsDxs 3pNEc374G/ndWj0TbIiIfqleebaH6BZM/fzTM0A2WNMiYeN4Y/sW/RgT/2W9VBZCpnPilGkGq7qRw yQCHHYMD2YAbgCn/qJlQ==; 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 1jTWA1-0005vV-2q; Tue, 28 Apr 2020 19:44:53 +0000 Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jTW9y-0005uU-UU; Tue, 28 Apr 2020 19:44:50 +0000 From: Matthew Wilcox To: linux-mm@kvack.org Subject: [PATCH 2/7] mm: Move pt_mm within struct page Date: Tue, 28 Apr 2020 12:44:44 -0700 Message-Id: <20200428194449.22615-3-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)" Instead of a per-arch word within struct page, use a formerly reserved word. This word is shared with page->mapping, so it must be cleared before being freed as it is checked in free_pages(). Signed-off-by: Matthew Wilcox (Oracle) --- arch/x86/mm/pgtable.c | 1 + include/linux/mm_types.h | 7 ++----- 2 files changed, 3 insertions(+), 5 deletions(-) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 7bd2c3a52297..f5f46737aea0 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -95,6 +95,7 @@ static inline void pgd_list_del(pgd_t *pgd) struct page *page = virt_to_page(pgd); list_del(&page->lru); + page->pt_mm = NULL; } #define UNSHARED_PTRS_PER_PGD \ diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 9bb34e2cd5a5..7efa12f4626f 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -149,11 +149,8 @@ struct page { pgtable_t pmd_huge_pte; }; }; - unsigned long _pt_pad_2; /* mapping */ - union { - struct mm_struct *pt_mm; /* x86 pgds only */ - atomic_t pt_frag_refcount; /* powerpc */ - }; + struct mm_struct *pt_mm; + atomic_t pt_frag_refcount; /* powerpc */ #if ALLOC_SPLIT_PTLOCKS spinlock_t *ptl; #else