From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f45.google.com (mail-pa0-f45.google.com [209.85.220.45]) by kanga.kvack.org (Postfix) with ESMTP id DF5606B0073 for ; Fri, 6 Feb 2015 09:51:25 -0500 (EST) Received: by mail-pa0-f45.google.com with SMTP id et14so17736337pad.4 for ; Fri, 06 Feb 2015 06:51:25 -0800 (PST) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTP id fh3si10492894pbb.187.2015.02.06.06.51.16 for ; Fri, 06 Feb 2015 06:51:16 -0800 (PST) From: "Kirill A. Shutemov" Subject: [PATCHv2, RESEND 08/19] mips: expose number of page table levels on Kconfig level Date: Fri, 6 Feb 2015 16:50:53 +0200 Message-Id: <1423234264-197684-9-git-send-email-kirill.shutemov@linux.intel.com> 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: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Ralf Baechle We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. Signed-off-by: Kirill A. Shutemov Cc: Ralf Baechle 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/mips/Kconfig | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 843713c05b79..2eea81795139 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -2535,6 +2535,11 @@ config STACKTRACE_SUPPORT bool default y +config PGTABLE_LEVELS + int + default 3 if 64BIT && !PAGE_SIZE_64KB + default 2 + source "init/Kconfig" source "kernel/Kconfig.freezer" -- 2.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org