Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757539AbbBFO4u (ORCPT ); Fri, 6 Feb 2015 09:56:50 -0500 Received: from mga11.intel.com ([192.55.52.93]:37867 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755510AbbBFOvQ (ORCPT ); Fri, 6 Feb 2015 09:51:16 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,529,1418112000"; d="scan'208";a="682003778" From: "Kirill A. Shutemov" To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Geert Uytterhoeven Subject: [PATCHv2, RESEND 07/19] m68k: mark PMD folded and expose number of page table levels Date: Fri, 6 Feb 2015 16:50:52 +0200 Message-Id: <1423234264-197684-8-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1423234264-197684-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1423234264-197684-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2653 Lines: 79 We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. Core mm expects __PAGETABLE_{PUD,PMD}_FOLDED to be defined if these page table levels folded. Signed-off-by: Kirill A. Shutemov Cc: Geert Uytterhoeven Tested-by: Guenter Roeck --- I've implemented accounting for pmd page tables as we have for pte (see mm->nr_ptes). It's requires a new counter in mm_struct: mm->nr_pmds. But the feature doesn't make any sense if an architecture has PMD level folded and it would be nice get rid of the counter in this case. The problem is that we cannot use __PAGETABLE_PMD_FOLDED in due to circular dependencies: -> -> In most cases wants to get definition of struct page and struct vm_area_struct. I've tried to split mm_struct into separate header file to be able to user there. But it doesn't fly on some architectures, like ARM: it wants mm_struct to implement tlb flushing. I don't see how to fix it without massive de-inlining or coverting a lot for inline functions to macros. This is other approach: expose number of page tables in use via Kconfig and use it in instead of __PAGETABLE_PMD_FOLDED from . --- arch/m68k/Kconfig | 4 ++++ arch/m68k/include/asm/pgtable_mm.h | 2 ++ 2 files changed, 6 insertions(+) diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 87b7c7581b1d..2dd8f63bfbbb 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -67,6 +67,10 @@ config HZ default 1000 if CLEOPATRA default 100 +config PGTABLE_LEVELS + default 2 if SUN3 || COLDFIRE + default 3 + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/m68k/include/asm/pgtable_mm.h b/arch/m68k/include/asm/pgtable_mm.h index 28a145bfbb71..35ed4a9981ae 100644 --- a/arch/m68k/include/asm/pgtable_mm.h +++ b/arch/m68k/include/asm/pgtable_mm.h @@ -54,10 +54,12 @@ */ #ifdef CONFIG_SUN3 #define PTRS_PER_PTE 16 +#define __PAGETABLE_PMD_FOLDED #define PTRS_PER_PMD 1 #define PTRS_PER_PGD 2048 #elif defined(CONFIG_COLDFIRE) #define PTRS_PER_PTE 512 +#define __PAGETABLE_PMD_FOLDED #define PTRS_PER_PMD 1 #define PTRS_PER_PGD 1024 #else -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/