diff options
| -rw-r--r-- | arch/arm/include/asm/tlb.h | 27 | ||||
| -rw-r--r-- | arch/ia64/include/asm/tlb.h | 41 | ||||
| -rw-r--r-- | include/asm-generic/tlb.h | 17 | ||||
| -rw-r--r-- | mm/memory.c | 9 |
4 files changed, 13 insertions, 81 deletions
diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h index 99a19512ee26..bdf2b8458ec1 100644 --- a/arch/arm/include/asm/tlb.h +++ b/arch/arm/include/asm/tlb.h @@ -33,18 +33,6 @@ #include <asm/pgalloc.h> #include <asm/tlbflush.h> -/* - * We need to delay page freeing for SMP as other CPUs can access pages - * which have been removed but not yet had their TLB entries invalidated. - * Also, as ARMv7 speculative prefetch can drag new entries into the TLB, - * we need to apply this same delaying tactic to ensure correct operation. - */ -#if defined(CONFIG_SMP) || defined(CONFIG_CPU_32v7) -#define tlb_fast_mode(tlb) 0 -#else -#define tlb_fast_mode(tlb) 1 -#endif - #define MMU_GATHER_BUNDLE 8 /* @@ -112,12 +100,10 @@ static inline void __tlb_alloc_page(struct mmu_gather *tlb) static inline void tlb_flush_mmu(struct mmu_gather *tlb) { tlb_flush(tlb); - if (!tlb_fast_mode(tlb)) { - free_pages_and_swap_cache(tlb->pages, tlb->nr); - tlb->nr = 0; - if (tlb->pages == tlb->local) - __tlb_alloc_page(tlb); - } + free_pages_and_swap_cache(tlb->pages, tlb->nr); + tlb->nr = 0; + if (tlb->pages == tlb->local) + __tlb_alloc_page(tlb); } static inline void @@ -178,11 +164,6 @@ tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) { - if (tlb_fast_mode(tlb)) { - free_page_and_swap_cache(page); - return 1; /* avoid calling tlb_flush_mmu */ - } - tlb->pages[tlb->nr++] = page; VM_BUG_ON(tlb->nr > tlb->max); return tlb->max - tlb->nr; diff --git a/arch/ia64/include/asm/tlb.h b/arch/ia64/include/asm/tlb.h index c3ffe3e54edc..ef3a9de01954 100644 --- a/arch/ia64/include/asm/tlb.h +++ b/arch/ia64/include/asm/tlb.h @@ -46,12 +46,6 @@ #include <asm/tlbflush.h> #include <asm/machvec.h> -#ifdef CONFIG_SMP -# define tlb_fast_mode(tlb) ((tlb)->nr == ~0U) -#else -# define tlb_fast_mode(tlb) (1) -#endif - /* * If we can't allocate a page to make a big batch of page pointers * to work on, then just handle a few from the on-stack structure. @@ -60,7 +54,7 @@ struct mmu_gather { struct mm_struct *mm; - unsigned int nr; /* == ~0U => fast mode */ + unsigned int nr; unsigned int max; unsigned char fullmm; /* non-zero means full mm flush */ unsigned char need_flush; /* really unmapped some PTEs? */ @@ -103,6 +97,7 @@ extern struct ia64_tr_entry *ia64_idtrs[NR_CPUS]; static inline void ia64_tlb_flush_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end) { + unsigned long i; unsigned int nr; if (!tlb->need_flush) @@ -141,13 +136,11 @@ ia64_tlb_flush_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long e /* lastly, release the freed pages */ nr = tlb->nr; - if (!tlb_fast_mode(tlb)) { - unsigned long i; - tlb->nr = 0; - tlb->start_addr = ~0UL; - for (i = 0; i < nr; ++i) - free_page_and_swap_cache(tlb->pages[i]); - } + + tlb->nr = 0; + tlb->start_addr = ~0UL; + for (i = 0; i < nr; ++i) + free_page_and_swap_cache(tlb->pages[i]); } static inline void __tlb_alloc_page(struct mmu_gather *tlb) @@ -167,20 +160,7 @@ tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned int full_m tlb->mm = mm; tlb->max = ARRAY_SIZE(tlb->local); tlb->pages = tlb->local; - /* - * Use fast mode if only 1 CPU is online. - * - * It would be tempting to turn on fast-mode for full_mm_flush as well. But this - * doesn't work because of speculative accesses and software prefetching: the page - * table of "mm" may (and usually is) the currently active page table and even - * though the kernel won't do any user-space accesses during the TLB shoot down, a - * compiler might use speculation or lfetch.fault on what happens to be a valid - * user-space address. This in turn could trigger a TLB miss fault (or a VHPT - * walk) and re-insert a TLB entry we just removed. Slow mode avoids such - * problems. (We could make fast-mode work by switching the current task to a - * different "mm" during the shootdown.) --davidm 08/02/2002 - */ - tlb->nr = (num_online_cpus() == 1) ? ~0U : 0; + tlb->nr = 0; tlb->fullmm = full_mm_flush; tlb->start_addr = ~0UL; } @@ -214,11 +194,6 @@ static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) { tlb->need_flush = 1; - if (tlb_fast_mode(tlb)) { - free_page_and_swap_cache(page); - return 1; /* avoid calling tlb_flush_mmu */ - } - if (!tlb->nr && tlb->pages == tlb->local) __tlb_alloc_page(tlb); diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index b1b1fa6ffffe..13821c339a41 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -97,11 +97,9 @@ struct mmu_gather { unsigned long start; unsigned long end; unsigned int need_flush : 1, /* Did free PTEs */ - fast_mode : 1; /* No batching */ - /* we are in the middle of an operation to clear * a full mm and can make some optimizations */ - unsigned int fullmm : 1, + fullmm : 1, /* we have performed an operation which * requires a complete flush of the tlb */ need_flush_all : 1; @@ -114,19 +112,6 @@ struct mmu_gather { #define HAVE_GENERIC_MMU_GATHER -static inline int tlb_fast_mode(struct mmu_gather *tlb) -{ -#ifdef CONFIG_SMP - return tlb->fast_mode; -#else - /* - * For UP we don't need to worry about TLB flush - * and page free order so much.. - */ - return 1; -#endif -} - void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm); void tlb_flush_mmu(struct mmu_gather *tlb); void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, diff --git a/mm/memory.c b/mm/memory.c index 6dc1882fbd72..61a262b08e53 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -220,7 +220,6 @@ void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm) tlb->start = -1UL; tlb->end = 0; tlb->need_flush = 0; - tlb->fast_mode = (num_possible_cpus() == 1); tlb->local.next = NULL; tlb->local.nr = 0; tlb->local.max = ARRAY_SIZE(tlb->__pages); @@ -244,9 +243,6 @@ void tlb_flush_mmu(struct mmu_gather *tlb) tlb_table_flush(tlb); #endif - if (tlb_fast_mode(tlb)) - return; - for (batch = &tlb->local; batch; batch = batch->next) { free_pages_and_swap_cache(batch->pages, batch->nr); batch->nr = 0; @@ -288,11 +284,6 @@ int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) VM_BUG_ON(!tlb->need_flush); - if (tlb_fast_mode(tlb)) { - free_page_and_swap_cache(page); - return 1; /* avoid calling tlb_flush_mmu() */ - } - batch = tlb->active; batch->pages[batch->nr++] = page; if (batch->nr == batch->max) { |