From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262735AbULQDpU (ORCPT ); Thu, 16 Dec 2004 22:45:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262741AbULQDpS (ORCPT ); Thu, 16 Dec 2004 22:45:18 -0500 Received: from omx1-ext.sgi.com ([192.48.179.11]:6608 "EHLO omx1.americas.sgi.com") by vger.kernel.org with ESMTP id S262735AbULQDfY (ORCPT ); Thu, 16 Dec 2004 22:35:24 -0500 Date: Thu, 16 Dec 2004 19:35:17 -0800 (PST) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: William Lee Irwin III cc: Hugh Dickins , Nick Piggin , Linus Torvalds , Andrew Morton , Benjamin Herrenschmidt , linux-mm@kvack.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org Subject: page fault scalability patch V13 [4/8]: atomic pte operations for i386 In-Reply-To: Message-ID: References: <41BBF923.6040207@yahoo.com.au> <20041212212456.GB2714@holomorphy.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Changelog * Atomic pte operations for i386 in regular and PAE modes Signed-off-by: Christoph Lameter Index: linux-2.6.9/include/asm-i386/pgtable.h =================================================================== --- linux-2.6.9.orig/include/asm-i386/pgtable.h 2004-12-15 15:00:20.000000000 -0800 +++ linux-2.6.9/include/asm-i386/pgtable.h 2004-12-16 10:08:38.000000000 -0800 @@ -413,6 +413,7 @@ #define __HAVE_ARCH_PTEP_SET_WRPROTECT #define __HAVE_ARCH_PTEP_MKDIRTY #define __HAVE_ARCH_PTE_SAME +#define __HAVE_ARCH_ATOMIC_TABLE_OPS #include #endif /* _I386_PGTABLE_H */ Index: linux-2.6.9/include/asm-i386/pgtable-3level.h =================================================================== --- linux-2.6.9.orig/include/asm-i386/pgtable-3level.h 2004-10-18 14:54:55.000000000 -0700 +++ linux-2.6.9/include/asm-i386/pgtable-3level.h 2004-12-16 10:13:11.000000000 -0800 @@ -6,7 +6,8 @@ * tables on PPro+ CPUs. * * Copyright (C) 1999 Ingo Molnar - */ + * August 26, 2004 added ptep_cmpxchg +*/ #define pte_ERROR(e) \ printk("%s:%d: bad pte %p(%08lx%08lx).\n", __FILE__, __LINE__, &(e), (e).pte_high, (e).pte_low) @@ -42,21 +43,11 @@ return pte_x(pte); } -/* Rules for using set_pte: the pte being assigned *must* be - * either not present or in a state where the hardware will - * not attempt to update the pte. In places where this is - * not possible, use pte_get_and_clear to obtain the old pte - * value and then use set_pte to update it. -ben - */ -static inline void set_pte(pte_t *ptep, pte_t pte) -{ - ptep->pte_high = pte.pte_high; - smp_wmb(); - ptep->pte_low = pte.pte_low; -} #define __HAVE_ARCH_SET_PTE_ATOMIC #define set_pte_atomic(pteptr,pteval) \ set_64bit((unsigned long long *)(pteptr),pte_val(pteval)) +#define set_pte(pteptr,pteval) \ + *(unsigned long long *)(pteptr) = pte_val(pteval) #define set_pmd(pmdptr,pmdval) \ set_64bit((unsigned long long *)(pmdptr),pmd_val(pmdval)) #define set_pgd(pgdptr,pgdval) \ @@ -142,4 +133,25 @@ #define __pte_to_swp_entry(pte) ((swp_entry_t){ (pte).pte_high }) #define __swp_entry_to_pte(x) ((pte_t){ 0, (x).val }) +/* Atomic PTE operations */ +#define ptep_xchg_flush(__vma, __addr, __ptep, __newval) \ +({ pte_t __r; \ + /* xchg acts as a barrier before the setting of the high bits. */\ + __r.pte_low = xchg(&(__ptep)->pte_low, (__newval).pte_low); \ + __r.pte_high = (__ptep)->pte_high; \ + (__ptep)->pte_high = (__newval).pte_high; \ + flush_tlb_page(__vma, __addr); \ + (__r); \ +}) + +#define __HAVE_ARCH_PTEP_XCHG_FLUSH + +static inline int ptep_cmpxchg(struct vm_area_struct *vma, unsigned long address, pte_t *ptep, pte_t oldval, pte_t newval) +{ + return cmpxchg8b((unsigned long long *)ptep, pte_val(oldval), pte_val(newval)) == pte_val(oldval); +} + +#define __HAVE_ARCH_GET_PTE_ATOMIC +#define get_pte_atomic(__ptep) __pte(get_64bit((unsigned long long *)(__ptep))) + #endif /* _I386_PGTABLE_3LEVEL_H */ Index: linux-2.6.9/include/asm-i386/pgtable-2level.h =================================================================== --- linux-2.6.9.orig/include/asm-i386/pgtable-2level.h 2004-10-18 14:54:31.000000000 -0700 +++ linux-2.6.9/include/asm-i386/pgtable-2level.h 2004-12-16 10:08:38.000000000 -0800 @@ -82,4 +82,7 @@ #define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_low }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) +/* Atomic PTE operations */ +#define ptep_cmpxchg(__vma,__a,__xp,__oldpte,__newpte) (cmpxchg(&(__xp)->pte_low, (__oldpte).pte_low, (__newpte).pte_low)==(__oldpte).pte_low) + #endif /* _I386_PGTABLE_2LEVEL_H */ Index: linux-2.6.9/include/asm-i386/pgalloc.h =================================================================== --- linux-2.6.9.orig/include/asm-i386/pgalloc.h 2004-10-18 14:53:10.000000000 -0700 +++ linux-2.6.9/include/asm-i386/pgalloc.h 2004-12-16 10:08:38.000000000 -0800 @@ -4,9 +4,12 @@ #include #include #include +#include #include #include /* for struct page */ +#define PMD_NONE 0L + #define pmd_populate_kernel(mm, pmd, pte) \ set_pmd(pmd, __pmd(_PAGE_TABLE + __pa(pte))) @@ -16,6 +19,19 @@ ((unsigned long long)page_to_pfn(pte) << (unsigned long long) PAGE_SHIFT))); } + +/* Atomic version */ +static inline int pmd_test_and_populate(struct mm_struct *mm, pmd_t *pmd, struct page *pte) +{ +#ifdef CONFIG_X86_PAE + return cmpxchg8b( ((unsigned long long *)pmd), PMD_NONE, _PAGE_TABLE + + ((unsigned long long)page_to_pfn(pte) << + (unsigned long long) PAGE_SHIFT) ) == PMD_NONE; +#else + return cmpxchg( (unsigned long *)pmd, PMD_NONE, _PAGE_TABLE + (page_to_pfn(pte) << PAGE_SHIFT)) == PMD_NONE; +#endif +} + /* * Allocate and free page tables. */ @@ -49,6 +65,7 @@ #define pmd_free(x) do { } while (0) #define __pmd_free_tlb(tlb,x) do { } while (0) #define pgd_populate(mm, pmd, pte) BUG() +#define pgd_test_and_populate(mm, pmd, pte) ({ BUG(); 1; }) #define check_pgt_cache() do { } while (0)