From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 16 Dec 2004 19:33:55 -0800 (PST) From: Christoph Lameter Subject: page fault scalability patch V13 [2/8]: ia64 atomic pte operations 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: owner-linux-mm@kvack.org Return-Path: 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 List-ID: Changelog * Provide atomic pte operations for ia64 * Enhanced parallelism in page fault handler if applied together with the generic patch Signed-off-by: Christoph Lameter Index: linux-2.6.9/include/asm-ia64/pgalloc.h =================================================================== --- linux-2.6.9.orig/include/asm-ia64/pgalloc.h 2004-10-18 14:53:06.000000000 -0700 +++ linux-2.6.9/include/asm-ia64/pgalloc.h 2004-11-19 07:54:19.000000000 -0800 @@ -34,6 +34,10 @@ #define pmd_quicklist (local_cpu_data->pmd_quick) #define pgtable_cache_size (local_cpu_data->pgtable_cache_sz) +/* Empty entries of PMD and PGD */ +#define PMD_NONE 0 +#define PGD_NONE 0 + static inline pgd_t* pgd_alloc_one_fast (struct mm_struct *mm) { @@ -78,12 +82,19 @@ preempt_enable(); } + static inline void pgd_populate (struct mm_struct *mm, pgd_t *pgd_entry, pmd_t *pmd) { pgd_val(*pgd_entry) = __pa(pmd); } +/* Atomic populate */ +static inline int +pgd_test_and_populate (struct mm_struct *mm, pgd_t *pgd_entry, pmd_t *pmd) +{ + return ia64_cmpxchg8_acq(pgd_entry,__pa(pmd), PGD_NONE) == PGD_NONE; +} static inline pmd_t* pmd_alloc_one_fast (struct mm_struct *mm, unsigned long addr) @@ -132,6 +143,13 @@ pmd_val(*pmd_entry) = page_to_phys(pte); } +/* Atomic populate */ +static inline int +pmd_test_and_populate (struct mm_struct *mm, pmd_t *pmd_entry, struct page *pte) +{ + return ia64_cmpxchg8_acq(pmd_entry, page_to_phys(pte), PMD_NONE) == PMD_NONE; +} + static inline void pmd_populate_kernel (struct mm_struct *mm, pmd_t *pmd_entry, pte_t *pte) { Index: linux-2.6.9/include/asm-ia64/pgtable.h =================================================================== --- linux-2.6.9.orig/include/asm-ia64/pgtable.h 2004-11-15 11:13:38.000000000 -0800 +++ linux-2.6.9/include/asm-ia64/pgtable.h 2004-11-19 07:55:35.000000000 -0800 @@ -30,6 +30,8 @@ #define _PAGE_P_BIT 0 #define _PAGE_A_BIT 5 #define _PAGE_D_BIT 6 +#define _PAGE_IG_BITS 53 +#define _PAGE_LOCK_BIT (_PAGE_IG_BITS+3) /* bit 56. Aligned to 8 bits */ #define _PAGE_P (1 << _PAGE_P_BIT) /* page present bit */ #define _PAGE_MA_WB (0x0 << 2) /* write back memory attribute */ @@ -58,6 +60,7 @@ #define _PAGE_PPN_MASK (((__IA64_UL(1) << IA64_MAX_PHYS_BITS) - 1) & ~0xfffUL) #define _PAGE_ED (__IA64_UL(1) << 52) /* exception deferral */ #define _PAGE_PROTNONE (__IA64_UL(1) << 63) +#define _PAGE_LOCK (__IA64_UL(1) << _PAGE_LOCK_BIT) /* Valid only for a PTE with the present bit cleared: */ #define _PAGE_FILE (1 << 1) /* see swap & file pte remarks below */ @@ -270,6 +273,8 @@ #define pte_dirty(pte) ((pte_val(pte) & _PAGE_D) != 0) #define pte_young(pte) ((pte_val(pte) & _PAGE_A) != 0) #define pte_file(pte) ((pte_val(pte) & _PAGE_FILE) != 0) +#define pte_locked(pte) ((pte_val(pte) & _PAGE_LOCK)!=0) + /* * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the * access rights: @@ -281,8 +286,15 @@ #define pte_mkyoung(pte) (__pte(pte_val(pte) | _PAGE_A)) #define pte_mkclean(pte) (__pte(pte_val(pte) & ~_PAGE_D)) #define pte_mkdirty(pte) (__pte(pte_val(pte) | _PAGE_D)) +#define pte_mkunlocked(pte) (__pte(pte_val(pte) & ~_PAGE_LOCK)) /* + * Lock functions for pte's + */ +#define ptep_lock(ptep) test_and_set_bit(_PAGE_LOCK_BIT, ptep) +#define ptep_unlock(ptep) { clear_bit(_PAGE_LOCK_BIT,ptep); smp_mb__after_clear_bit(); } +#define ptep_unlock_set(ptep, val) set_pte(ptep, pte_mkunlocked(val)) +/* * Macro to a page protection value as "uncacheable". Note that "protection" is really a * misnomer here as the protection value contains the memory attribute bits, dirty bits, * and various other bits as well. @@ -342,7 +354,6 @@ #define pte_unmap_nested(pte) do { } while (0) /* atomic versions of the some PTE manipulations: */ - static inline int ptep_test_and_clear_young (pte_t *ptep) { @@ -414,6 +425,26 @@ #endif } +/* + * IA-64 doesn't have any external MMU info: the page tables contain all the necessary + * information. However, we use this routine to take care of any (delayed) i-cache + * flushing that may be necessary. + */ +extern void update_mmu_cache (struct vm_area_struct *vma, unsigned long vaddr, pte_t pte); + +static inline int +ptep_cmpxchg (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, pte_t oldval, pte_t newval) +{ + /* + * IA64 defers icache flushes. If the new pte is executable we may + * have to flush the icache to insure cache coherency immediately + * after the cmpxchg. + */ + if (pte_exec(newval)) + update_mmu_cache(vma, addr, newval); + return ia64_cmpxchg8_acq(&ptep->pte, newval.pte, oldval.pte) == oldval.pte; +} + static inline int pte_same (pte_t a, pte_t b) { @@ -476,13 +507,6 @@ struct vm_area_struct * prev, unsigned long start, unsigned long end); #endif -/* - * IA-64 doesn't have any external MMU info: the page tables contain all the necessary - * information. However, we use this routine to take care of any (delayed) i-cache - * flushing that may be necessary. - */ -extern void update_mmu_cache (struct vm_area_struct *vma, unsigned long vaddr, pte_t pte); - #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS /* * Update PTEP with ENTRY, which is guaranteed to be a less @@ -560,6 +584,8 @@ #define __HAVE_ARCH_PTEP_MKDIRTY #define __HAVE_ARCH_PTE_SAME #define __HAVE_ARCH_PGD_OFFSET_GATE +#define __HAVE_ARCH_ATOMIC_TABLE_OPS +#define __HAVE_ARCH_LOCK_TABLE_OPS #include #endif /* _ASM_IA64_PGTABLE_H */ -- 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: aart@kvack.org