From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756958AbYAPWZZ (ORCPT ); Wed, 16 Jan 2008 17:25:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754416AbYAPWPp (ORCPT ); Wed, 16 Jan 2008 17:15:45 -0500 Received: from cantor.suse.de ([195.135.220.2]:55261 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752134AbYAPWPa (ORCPT ); Wed, 16 Jan 2008 17:15:30 -0500 From: Andi Kleen References: <200801161114.239449000@suse.de> In-Reply-To: <200801161114.239449000@suse.de> To: linux-kernel@vger.kernel.org, mingo@elte.hu, tglx@linutronix.de, jbeulich@novell.com, venkatesh.pallipadi@intel.com Subject: [PATCH] [29/36] CPA: Only unmap kernel init pages in text mapping when CONFIG_DEBUG_RODATA is set Message-Id: <20080116221529.38C29150C8@wotan.suse.de> Date: Wed, 16 Jan 2008 23:15:29 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Otherwise the kernel will likely always run with 4K pages instead of 2MB pages, which is costly in terms of TLBs. Also optimize it a little bit by using only a single change_page_attr() calls. This is particularly useful if debugging is enabled inside it because it spams the logs much less. Signed-off-by: Andi Kleen Acked-by: Jan Beulich --- arch/x86/mm/init_64.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) Index: linux/arch/x86/mm/init_64.c =================================================================== --- linux.orig/arch/x86/mm/init_64.c +++ linux/arch/x86/mm/init_64.c @@ -694,13 +694,16 @@ void free_init_pages(char *what, unsigne init_page_count(virt_to_page(addr)); memset((void *)(addr & ~(PAGE_SIZE-1)), POISON_FREE_INITMEM, PAGE_SIZE); - if (addr >= __START_KERNEL_map) - change_page_attr_addr(addr, 1, __pgprot(0)); free_page(addr); totalram_pages++; } - if (addr > __START_KERNEL_map) +#ifdef CONFIG_DEBUG_RODATA + if (begin >= __START_KERNEL_map) { + change_page_attr_addr(begin, (end - begin)/PAGE_SIZE, + __pgprot(0)); global_flush_tlb(); + } +#endif } void free_initmem(void)