On 06/26/2012 01:14 AM, Seth Jennings wrote: > 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 <[email protected]>
Anyway, we don't matter INVLPG_BREAK_EVEN_PAGES's optimization point is 8 or something. We do care only it works without big problem. I believe after Alex's patch is settle down, we can fix it if it's wrong. But it shouldn't prevent merging this patch. Acked-by: Minchan Kim <[email protected]> Nitpick: I expect you change __HAVE_LOCAL_XXX to __HAVE_ARCH_LOCAL_XXX in next spin. :) > --- > 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 */ -- Kind regards, Minchan Kim _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
