lkml.org 
[lkml]   [2012]   [Jun]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3/3] x86: add local_tlb_flush_kernel_range()
    Date
    This patch adds support for a local_tlb_flush_kernel_range()
    function for the x86 arch. This function allows for CPU-local
    TLB flushing, potentially using invlpg for single entry flushing,
    using an arch independent function name.

    Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
    ---
    arch/x86/include/asm/tlbflush.h | 21 +++++++++++++++++++++
    1 file changed, 21 insertions(+)

    diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
    index 36a1a2a..92a280b 100644
    --- a/arch/x86/include/asm/tlbflush.h
    +++ b/arch/x86/include/asm/tlbflush.h
    @@ -168,4 +168,25 @@ static inline void flush_tlb_kernel_range(unsigned long start,
    flush_tlb_all();
    }

    +#define __HAVE_LOCAL_FLUSH_TLB_KERNEL_RANGE
    +/*
    + * INVLPG_BREAK_EVEN_PAGES is the number of pages after which single tlb
    + * flushing becomes more costly than just doing a complete tlb flush.
    + * While this break even point varies among x86 hardware, tests have shown
    + * that 8 is a good generic value.
    +*/
    +#define INVLPG_BREAK_EVEN_PAGES 8
    +static inline void local_flush_tlb_kernel_range(unsigned long start,
    + unsigned long end)
    +{
    + if (cpu_has_invlpg &&
    + (end - start)/PAGE_SIZE <= INVLPG_BREAK_EVEN_PAGES) {
    + while (start < end) {
    + __flush_tlb_single(start);
    + start += PAGE_SIZE;
    + }
    + } else
    + local_flush_tlb();
    +}
    +
    #endif /* _ASM_X86_TLBFLUSH_H */
    --
    1.7.9.5


    \
     
     \ /
      Last update: 2012-06-25 19:21    [W:2.082 / U:0.236 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site