Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932237AbVIYQAY (ORCPT ); Sun, 25 Sep 2005 12:00:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932238AbVIYQAY (ORCPT ); Sun, 25 Sep 2005 12:00:24 -0400 Received: from silver.veritas.com ([143.127.12.111]:55990 "EHLO silver.veritas.com") by vger.kernel.org with ESMTP id S932237AbVIYQAX (ORCPT ); Sun, 25 Sep 2005 12:00:23 -0400 Date: Sun, 25 Sep 2005 16:59:56 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@goblin.wat.veritas.com To: Andrew Morton cc: "David S. Miller" , Russell King , Ian Molton , Tony Luck , linux-kernel@vger.kernel.org Subject: [PATCH 12/21] mm: tlb_gather_mmu get_cpu_var In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 25 Sep 2005 16:00:23.0109 (UTC) FILETIME=[3C7A6750:01C5C1EA] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5554 Lines: 159 tlb_gather_mmu dates from before kernel preemption was allowed, and uses smp_processor_id or __get_cpu_var to find its per-cpu mmu_gather. That works because it's currently only called after getting page_table_lock, which is not dropped until after the matching tlb_finish_mmu. But don't rely on that, it will soon change: now disable preemption internally by proper get_cpu_var in tlb_gather_mmu, put_cpu_var in tlb_finish_mmu. Signed-off-by: Hugh Dickins --- include/asm-arm/tlb.h | 5 +++-- include/asm-arm26/tlb.h | 7 ++++--- include/asm-generic/tlb.h | 10 +++++----- include/asm-ia64/tlb.h | 6 ++++-- include/asm-sparc64/tlb.h | 4 +++- 5 files changed, 19 insertions(+), 13 deletions(-) --- mm11/include/asm-arm/tlb.h 2005-06-17 20:48:29.000000000 +0100 +++ mm12/include/asm-arm/tlb.h 2005-09-24 19:28:56.000000000 +0100 @@ -39,8 +39,7 @@ DECLARE_PER_CPU(struct mmu_gather, mmu_g static inline struct mmu_gather * tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) { - int cpu = smp_processor_id(); - struct mmu_gather *tlb = &per_cpu(mmu_gathers, cpu); + struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); tlb->mm = mm; tlb->freed = 0; @@ -65,6 +64,8 @@ tlb_finish_mmu(struct mmu_gather *tlb, u /* keep the page table cache within bounds */ check_pgt_cache(); + + put_cpu_var(mmu_gathers); } static inline unsigned int tlb_is_full_mm(struct mmu_gather *tlb) --- mm11/include/asm-arm26/tlb.h 2005-06-17 20:48:29.000000000 +0100 +++ mm12/include/asm-arm26/tlb.h 2005-09-24 19:28:56.000000000 +0100 @@ -17,13 +17,12 @@ struct mmu_gather { unsigned int avoided_flushes; }; -extern struct mmu_gather mmu_gathers[NR_CPUS]; +DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); static inline struct mmu_gather * tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) { - int cpu = smp_processor_id(); - struct mmu_gather *tlb = &mmu_gathers[cpu]; + struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); tlb->mm = mm; tlb->freed = 0; @@ -52,6 +51,8 @@ tlb_finish_mmu(struct mmu_gather *tlb, u /* keep the page table cache within bounds */ check_pgt_cache(); + + put_cpu_var(mmu_gathers); } --- mm11/include/asm-generic/tlb.h 2005-09-21 12:16:48.000000000 +0100 +++ mm12/include/asm-generic/tlb.h 2005-09-24 19:28:56.000000000 +0100 @@ -35,9 +35,7 @@ #endif /* struct mmu_gather is an opaque type used by the mm code for passing around - * any data needed by arch specific code for tlb_remove_page. This structure - * can be per-CPU or per-MM as the page table lock is held for the duration of - * TLB shootdown. + * any data needed by arch specific code for tlb_remove_page. */ struct mmu_gather { struct mm_struct *mm; @@ -57,7 +55,7 @@ DECLARE_PER_CPU(struct mmu_gather, mmu_g static inline struct mmu_gather * tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) { - struct mmu_gather *tlb = &per_cpu(mmu_gathers, smp_processor_id()); + struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); tlb->mm = mm; @@ -85,7 +83,7 @@ tlb_flush_mmu(struct mmu_gather *tlb, un /* tlb_finish_mmu * Called at the end of the shootdown operation to free up any resources - * that were required. The page table lock is still held at this point. + * that were required. */ static inline void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) @@ -101,6 +99,8 @@ tlb_finish_mmu(struct mmu_gather *tlb, u /* keep the page table cache within bounds */ check_pgt_cache(); + + put_cpu_var(mmu_gathers); } static inline unsigned int --- mm11/include/asm-ia64/tlb.h 2005-06-17 20:48:29.000000000 +0100 +++ mm12/include/asm-ia64/tlb.h 2005-09-24 19:28:56.000000000 +0100 @@ -129,7 +129,7 @@ ia64_tlb_flush_mmu (struct mmu_gather *t static inline struct mmu_gather * tlb_gather_mmu (struct mm_struct *mm, unsigned int full_mm_flush) { - struct mmu_gather *tlb = &__get_cpu_var(mmu_gathers); + struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); tlb->mm = mm; /* @@ -154,7 +154,7 @@ tlb_gather_mmu (struct mm_struct *mm, un /* * Called at the end of the shootdown operation to free up any resources that were - * collected. The page table lock is still held at this point. + * collected. */ static inline void tlb_finish_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end) @@ -174,6 +174,8 @@ tlb_finish_mmu (struct mmu_gather *tlb, /* keep the page table cache within bounds */ check_pgt_cache(); + + put_cpu_var(mmu_gathers); } static inline unsigned int --- mm11/include/asm-sparc64/tlb.h 2005-06-17 20:48:29.000000000 +0100 +++ mm12/include/asm-sparc64/tlb.h 2005-09-24 19:28:56.000000000 +0100 @@ -44,7 +44,7 @@ extern void flush_tlb_pending(void); static inline struct mmu_gather *tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) { - struct mmu_gather *mp = &__get_cpu_var(mmu_gathers); + struct mmu_gather *mp = &get_cpu_var(mmu_gathers); BUG_ON(mp->tlb_nr); @@ -97,6 +97,8 @@ static inline void tlb_finish_mmu(struct /* keep the page table cache within bounds */ check_pgt_cache(); + + put_cpu_var(mmu_gathers); } static inline unsigned int tlb_is_full_mm(struct mmu_gather *mp) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/