Messages in this thread Patch in this message | | | From | Rik van Riel <> | Subject | [PATCH 5/7] Add freed_tables argument to flush_tlb_mm_range | Date | Mon, 24 Sep 2018 14:37:57 -0400 |
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Add an argument to flush_tlb_mm_range to indicate whether page tables are about to be freed after this TLB flush. This allows for an optimization of flush_tlb_mm_range to skip CPUs in lazy TLB mode.
No functional changes.
Signed-off-by: Rik van Riel <riel@surriel.com> --- arch/x86/include/asm/tlb.h | 6 ++++-- arch/x86/include/asm/tlbflush.h | 12 ++++++++---- arch/x86/kernel/ldt.c | 2 +- arch/x86/kernel/vm86_32.c | 2 +- arch/x86/mm/tlb.c | 3 ++- 5 files changed, 16 insertions(+), 9 deletions(-)
diff --git a/arch/x86/include/asm/tlb.h b/arch/x86/include/asm/tlb.h index cb0a1f470980..b9237a1f567f 100644 --- a/arch/x86/include/asm/tlb.h +++ b/arch/x86/include/asm/tlb.h @@ -9,9 +9,11 @@ #define tlb_flush(tlb) \ { \ if (!tlb->fullmm && !tlb->need_flush_all) \ - flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end, 0UL); \ + flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end, 0UL, \ + tlb->freed_tables); \ else \ - flush_tlb_mm_range(tlb->mm, 0UL, TLB_FLUSH_ALL, 0UL); \ + flush_tlb_mm_range(tlb->mm, 0UL, TLB_FLUSH_ALL, 0UL, \ + tlb->freed_tables); \ } #include <asm-generic/tlb.h> diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 82898cd3d933..ae1ef755cb94 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -515,19 +515,23 @@ struct flush_tlb_info { #define local_flush_tlb() __flush_tlb() -#define flush_tlb_mm(mm) flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL) +/* Simultaneous unmap operations could have freed page tables. */ +#define flush_tlb_mm(mm) \ + flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL, true) +/* The operations calling flush_tlb_range do not free page tables. */ #define flush_tlb_range(vma, start, end) \ - flush_tlb_mm_range(vma->vm_mm, start, end, vma->vm_flags) + flush_tlb_mm_range(vma->vm_mm, start, end, vma->vm_flags, false) extern void flush_tlb_all(void); extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, - unsigned long end, unsigned long vmflag); + unsigned long end, unsigned long vmflag, + bool freed_tables); extern void flush_tlb_kernel_range(unsigned long start, unsigned long end); static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a) { - flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, VM_NONE); + flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, VM_NONE, false); } void native_flush_tlb_others(const struct cpumask *cpumask, diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index 26d713ecad34..2c2291fa14b3 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -190,7 +190,7 @@ map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot) } va = (unsigned long)ldt_slot_va(slot); - flush_tlb_mm_range(mm, va, va + LDT_SLOT_STRIDE, 0); + flush_tlb_mm_range(mm, va, va + LDT_SLOT_STRIDE, 0, false); ldt->slot = slot; #endif diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c index 5edb27f1a2c4..51024424dfbe 100644 --- a/arch/x86/kernel/vm86_32.c +++ b/arch/x86/kernel/vm86_32.c @@ -199,7 +199,7 @@ static void mark_screen_rdonly(struct mm_struct *mm) pte_unmap_unlock(pte, ptl); out: up_write(&mm->mmap_sem); - flush_tlb_mm_range(mm, 0xA0000, 0xA0000 + 32*PAGE_SIZE, 0UL); + flush_tlb_mm_range(mm, 0xA0000, 0xA0000 + 32*PAGE_SIZE, 0UL, false); } diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index ac05d61cc90e..62f147b0f6b7 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -571,7 +571,8 @@ void native_flush_tlb_others(const struct cpumask *cpumask, static unsigned long tlb_single_page_flush_ceiling __read_mostly = 33; void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, - unsigned long end, unsigned long vmflag) + unsigned long end, unsigned long vmflag, + bool freed_tables) { int cpu; -- 2.17.1
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