From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752644AbYCLCyQ (ORCPT ); Tue, 11 Mar 2008 22:54:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753418AbYCLCxd (ORCPT ); Tue, 11 Mar 2008 22:53:33 -0400 Received: from smtp-out01.alice-dsl.net ([88.44.60.11]:9280 "EHLO smtp-out01.alice-dsl.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751918AbYCLCxb (ORCPT ); Tue, 11 Mar 2008 22:53:31 -0400 From: Andi Kleen References: <20080312353.598285931@firstfloor.org> In-Reply-To: <20080312353.598285931@firstfloor.org> To: andreas.herrmann3@amd.com, tglx@linutronix.de, mingo@elte.hu, linux-kernel@vger.kernel.org Subject: [PATCH] [3/7] Add set_memory_4k to pageattr.c Message-Id: <20080312025329.A74C71B41D1@basil.firstfloor.org> Date: Wed, 12 Mar 2008 03:53:29 +0100 (CET) X-OriginalArrivalTime: 12 Mar 2008 02:46:57.0551 (UTC) FILETIME=[56B7F9F0:01C883EB] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a new function to force split large pages into 4k pages. This is needed for some followup optimizations. I had to add a new field to cpa_data to pass down the information that try_preserve_large_page should not run. Right now no set_page_4k() because I didn't need it and all the specialized users I have in mind would be more comfortable with pure addresses. I also didn't export it because it's unlikely external code needs it. Signed-off-by: Andi Kleen Index: linux/arch/x86/mm/pageattr.c =================================================================== --- linux.orig/arch/x86/mm/pageattr.c +++ linux/arch/x86/mm/pageattr.c @@ -28,6 +28,7 @@ struct cpa_data { int numpages; int flushtlb; unsigned long pfn; + unsigned force_split : 1; }; #ifdef CONFIG_X86_64 @@ -259,6 +260,9 @@ try_preserve_large_page(pte_t *kpte, uns int i, do_split = 1; unsigned int level; + if (cpa->force_split) + return 1; + spin_lock_irqsave(&pgd_lock, flags); /* * Check for races, another CPU might have split this page @@ -693,7 +697,8 @@ static inline int cache_attr(pgprot_t at } static int change_page_attr_set_clr(unsigned long addr, int numpages, - pgprot_t mask_set, pgprot_t mask_clr) + pgprot_t mask_set, pgprot_t mask_clr, + int force_split) { struct cpa_data cpa; int ret, cache, checkalias; @@ -704,7 +709,7 @@ static int change_page_attr_set_clr(unsi */ mask_set = canon_pgprot(mask_set); mask_clr = canon_pgprot(mask_clr); - if (!pgprot_val(mask_set) && !pgprot_val(mask_clr)) + if (!pgprot_val(mask_set) && !pgprot_val(mask_clr) && !force_split) return 0; /* Ensure we are PAGE_SIZE aligned */ @@ -721,6 +726,7 @@ static int change_page_attr_set_clr(unsi cpa.mask_set = mask_set; cpa.mask_clr = mask_clr; cpa.flushtlb = 0; + cpa.force_split = force_split; /* No alias checking for _NX bit modifications */ checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX; @@ -759,13 +765,13 @@ out: static inline int change_page_attr_set(unsigned long addr, int numpages, pgprot_t mask) { - return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0)); + return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0); } static inline int change_page_attr_clear(unsigned long addr, int numpages, pgprot_t mask) { - return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask); + return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0); } int set_memory_uc(unsigned long addr, int numpages) @@ -809,6 +815,12 @@ int set_memory_np(unsigned long addr, in return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_PRESENT)); } +int set_memory_4k(unsigned long addr, int numpages) +{ + return change_page_attr_set_clr(addr, numpages, __pgprot(0), + __pgprot(0), 1); +} + int set_pages_uc(struct page *page, int numpages) { unsigned long addr = (unsigned long)page_address(page); Index: linux/include/asm-x86/cacheflush.h =================================================================== --- linux.orig/include/asm-x86/cacheflush.h +++ linux/include/asm-x86/cacheflush.h @@ -41,6 +41,7 @@ int set_memory_nx(unsigned long addr, in int set_memory_ro(unsigned long addr, int numpages); int set_memory_rw(unsigned long addr, int numpages); int set_memory_np(unsigned long addr, int numpages); +int set_memory_4k(unsigned long addr, int numpages); void clflush_cache_range(void *addr, unsigned int size);