Re: [PATCH/RFC v2 1/3] tlb: mmu_gather: introduce CONFIG_MMU_GATHER_TABLE_FREE_COMMON

[Peter Zijlstra]

On Sat, Dec 18, 2021 at 09:52:04PM +0300, Nikita Yushchenko wrote:
> For architectures that use free_page_and_swap_cache() as their
> __tlb_remove_table(), place that common implementation into
> mm/mmu_gather.c, ifdef'ed by CONFIG_MMU_GATHER_TABLE_FREE_COMMON.
> 
> Signed-off-by: Nikita Yushchenko <nikita.yushchenko@xxxxxxxxxxxxx>
> ---
>  arch/Kconfig                 |  3 +++
>  arch/arm/Kconfig             |  1 +
>  arch/arm/include/asm/tlb.h   |  5 -----
>  arch/arm64/Kconfig           |  1 +
>  arch/arm64/include/asm/tlb.h |  5 -----
>  arch/x86/Kconfig             |  1 +
>  arch/x86/include/asm/tlb.h   | 14 --------------
>  include/asm-generic/tlb.h    |  5 +++++
>  mm/mmu_gather.c              | 10 ++++++++++
>  9 files changed, 21 insertions(+), 24 deletions(-)
> 
> diff --git a/arch/Kconfig b/arch/Kconfig
> index d3c4ab249e9c..9eba553cd86f 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -415,6 +415,9 @@ config HAVE_ARCH_JUMP_LABEL_RELATIVE
>  config MMU_GATHER_TABLE_FREE
>  	bool
>  
> +config MMU_GATHER_TABLE_FREE_COMMON
> +	bool

I don't like that name... The point isn't that it's common, the point is
that the page-table's are backed by pages.