From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f46.google.com (mail-pb0-f46.google.com [209.85.160.46]) by kanga.kvack.org (Postfix) with ESMTP id 5C1746B0069 for ; Mon, 7 Oct 2013 09:54:45 -0400 (EDT) Received: by mail-pb0-f46.google.com with SMTP id rq2so7137692pbb.33 for ; Mon, 07 Oct 2013 06:54:45 -0700 (PDT) From: "Kirill A. Shutemov" Subject: [PATCHv5 01/11] mm: avoid increase sizeof(struct page) due to split page table lock Date: Mon, 7 Oct 2013 16:54:03 +0300 Message-Id: <1381154053-4848-2-git-send-email-kirill.shutemov@linux.intel.com> In-Reply-To: <1381154053-4848-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1381154053-4848-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Alex Thorlton , Ingo Molnar , Andrew Morton , Naoya Horiguchi Cc: "Eric W . Biederman" , "Paul E . McKenney" , Al Viro , Andi Kleen , Andrea Arcangeli , Dave Hansen , Dave Jones , David Howells , Frederic Weisbecker , Johannes Weiner , Kees Cook , Mel Gorman , Michael Kerrisk , Oleg Nesterov , Peter Zijlstra , Rik van Riel , Robin Holt , Sedat Dilek , Srikar Dronamraju , Thomas Gleixner , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" CONFIG_GENERIC_LOCKBREAK increases sizeof(spinlock_t) to 8 bytes. It leads to increase sizeof(struct page) by 4 bytes on 32-bit system if split page table lock is in use, since page->ptl shares space in union with longs and pointers. Let's disable split page table lock on 32-bit systems with GENERIC_LOCKBREAK enabled. Signed-off-by: Kirill A. Shutemov --- mm/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/Kconfig b/mm/Kconfig index 026771a9b0..6f5be0dac9 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -212,6 +212,7 @@ config SPLIT_PTLOCK_CPUS default "999999" if ARM && !CPU_CACHE_VIPT default "999999" if PARISC && !PA20 default "999999" if DEBUG_SPINLOCK || DEBUG_LOCK_ALLOC + default "999999" if !64BIT && GENERIC_LOCKBREAK default "4" # -- 1.8.4.rc3 -- 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