Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754443Ab2KQDsB (ORCPT ); Fri, 16 Nov 2012 22:48:01 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:16795 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754101Ab2KQDk1 (ORCPT ); Fri, 16 Nov 2012 22:40:27 -0500 From: Yinghai Lu To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Jacob Shin Cc: Andrew Morton , Stefano Stabellini , Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org, Yinghai Lu Subject: [PATCH v8 18/46] x86, mm: Use big page size for small memory range Date: Fri, 16 Nov 2012 19:38:55 -0800 Message-Id: <1353123563-3103-19-git-send-email-yinghai@kernel.org> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1353123563-3103-1-git-send-email-yinghai@kernel.org> References: <1353123563-3103-1-git-send-email-yinghai@kernel.org> X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2433 Lines: 76 We could map small range in the middle of big range at first, so should use big page size at first to avoid using small page size to break down page table. Only can set big page bit when that range has ram area around it. -v2: fix 32bit boundary checking. We can not count ram above max_low_pfn for 32 bit. Signed-off-by: Yinghai Lu --- arch/x86/mm/init.c | 37 +++++++++++++++++++++++++++++++++++++ 1 files changed, 37 insertions(+), 0 deletions(-) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index bb44e9f..da591eb 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -88,6 +88,40 @@ static int __meminit save_mr(struct map_range *mr, int nr_range, return nr_range; } +/* + * adjust the page_size_mask for small range to go with + * big page size instead small one if nearby are ram too. + */ +static void __init_refok adjust_range_page_size_mask(struct map_range *mr, + int nr_range) +{ + int i; + + for (i = 0; i < nr_range; i++) { + if ((page_size_mask & (1<> PAGE_SHIFT) > max_low_pfn) + continue; +#endif + + if (memblock_is_region_memory(start, end - start)) + mr[i].page_size_mask |= 1<