From d970a5218088a856d80acd9da6c6742f55cb0a0d Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 28 Jul 2005 21:15:35 -0700 Subject: [PATCH] x86_64: Fix some comments in tlbflush.h Were either outdated or misleading. Signed-off-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-x86_64/tlbflush.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'include/asm-x86_64/tlbflush.h') diff --git a/include/asm-x86_64/tlbflush.h b/include/asm-x86_64/tlbflush.h index 061742382520..505b0cf906de 100644 --- a/include/asm-x86_64/tlbflush.h +++ b/include/asm-x86_64/tlbflush.h @@ -56,8 +56,9 @@ extern unsigned long pgkern_mask; * - flush_tlb_kernel_range(start, end) flushes a range of kernel pages * - flush_tlb_pgtables(mm, start, end) flushes a range of page tables * - * ..but the x86_64 has somewhat limited tlb flushing capabilities, - * and page-granular flushes are available only on i486 and up. + * x86-64 can only flush individual pages or full VMs. For a range flush + * we always do the full VM. Might be worth trying if for a small + * range a few INVLPGs in a row are a win. */ #ifndef CONFIG_SMP @@ -115,7 +116,9 @@ static inline void flush_tlb_range(struct vm_area_struct * vma, unsigned long st static inline void flush_tlb_pgtables(struct mm_struct *mm, unsigned long start, unsigned long end) { - /* x86_64 does not keep any page table caches in TLB */ + /* x86_64 does not keep any page table caches in a software TLB. + The CPUs do in their hardware TLBs, but they are handled + by the normal TLB flushing algorithms. */ } #endif /* _X8664_TLBFLUSH_H */ -- cgit v1.2.3