Re: [PATCH 2/2] MIPS: don't select ARCH_HAS_PTE_SPECIAL

[Guenter Roeck]

On Mon, Jul 01, 2019 at 05:18:18PM +0200, Christoph Hellwig wrote:
> MIPS doesn't really have a proper pte_special implementation, just
> stubs.  It turns out they were not enough to make get_user_pages_fast
> work, so drop the select.  This means get_user_pages_fast won't
> actually use the fast path for non-hugepage mappings, so someone who
> actually knows about mips page table management should look into
> adding real pte_special support.
> 
> Fixes: eb9488e58bbc ("MIPS: use the generic get_user_pages_fast code")
> Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
>  arch/mips/Kconfig | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index b1e42f0e4ed0..7957d3457156 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -6,7 +6,6 @@ config MIPS
>  	select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT
>  	select ARCH_CLOCKSOURCE_DATA
>  	select ARCH_HAS_ELF_RANDOMIZE
> -	select ARCH_HAS_PTE_SPECIAL
>  	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
>  	select ARCH_HAS_UBSAN_SANITIZE_ALL
>  	select ARCH_SUPPORTS_UPROBES
> -- 
> 2.20.1
>