Re: [PATCH v2 3/3] x86: Support local_flush_tlb_kernel_range

From: Minchan Kim
Date: Thu May 17 2012 - 04:10:44 EST


Isn't there anyone for taking a time to review this patch? :)

On 05/16/2012 11:05 AM, Minchan Kim wrote:

> The zsmalloc [un]maps non-physical contiguos pages to contiguous
> virual address frequently so it needs frequent tlb-flush.
> Now x86 doesn't support common utility function for flushing just
> a few tlb entries so zsmalloc have been used set_pte and __flush_tlb_one
> which are x86 specific functions. It means zsmalloc have a dependency
> with x86.
>
> This patch adds new function, local_flush_tlb_kernel_range which
> are good candidate for being common utility function because other
> architecture(ex, MIPS, sh, unicore32, arm, score) already have
> supportd it.
>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> Cc: David Howells <dhowells@xxxxxxxxxx>
> Cc: x86@xxxxxxxxxx
> Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
> ---
> arch/x86/include/asm/tlbflush.h | 12 ++++++++++++
> drivers/staging/zsmalloc/Kconfig | 2 +-
> 2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
> index 4ece077..6e1253a 100644
> --- a/arch/x86/include/asm/tlbflush.h
> +++ b/arch/x86/include/asm/tlbflush.h
> @@ -172,4 +172,16 @@ static inline void flush_tlb_kernel_range(unsigned long start,
> flush_tlb_all();
> }
>
> +static inline void local_flush_tlb_kernel_range(unsigned long start,
> + unsigned long end)
> +{
> + if (cpu_has_invlpg) {
> + while (start < end) {
> + __flush_tlb_single(start);
> + start += PAGE_SIZE;
> + }
> + } else
> + local_flush_tlb();
> +}
> +
> #endif /* _ASM_X86_TLBFLUSH_H */
> diff --git a/drivers/staging/zsmalloc/Kconfig b/drivers/staging/zsmalloc/Kconfig
> index def2483..29819b8 100644
> --- a/drivers/staging/zsmalloc/Kconfig
> +++ b/drivers/staging/zsmalloc/Kconfig
> @@ -3,7 +3,7 @@ config ZSMALLOC
> # arch dependency is because of the use of local_unmap_kernel_range
> # in zsmalloc-main.c.
> # TODO: implement local_unmap_kernel_range in all architecture.
> - depends on (ARM || MIPS || SUPERH)
> + depends on (ARM || MIPS || SUPERH || X86)
> default n
> help
> zsmalloc is a slab-based memory allocator designed to store



--
Kind regards,
Minchan Kim
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