Re: [PATCH v5 10/11] mm/Kconfig: Adds config option to track lockless pagetable walks

[Qian Cai]

> On Oct 2, 2019, at 9:36 PM, Leonardo Bras <leona...@linux.ibm.com> wrote:
> 
> Adds config option LOCKLESS_PAGE_TABLE_WALK_TRACKING to make possible
> enabling tracking lockless pagetable walks directly from kernel config.

Can’t this name and all those new *lockless* function names be shorter? There 
are many functions name with *_locked, so how about dropping lockless at all, 
i.e., PAGE_TABLE_WALK_TRACKING blah blah?

> 
> Signed-off-by: Leonardo Bras <leona...@linux.ibm.com>
> ---
> mm/Kconfig | 11 +++++++++++
> 1 file changed, 11 insertions(+)
> 
> diff --git a/mm/Kconfig b/mm/Kconfig
> index a5dae9a7eb51..00f487a0122f 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -736,4 +736,15 @@ config ARCH_HAS_PTE_SPECIAL
> config ARCH_HAS_HUGEPD
>    bool
> 
> +config LOCKLESS_PAGE_TABLE_WALK_TRACKING
> +    bool "Track (and optimize) lockless page table walks"
> +    default n
> +
> +    help
> +      Maintain a reference count of active lockless page table
> +      walkers. This adds 4 bytes to struct mm size, and two atomic
> +      operations to calls such as get_user_pages_fast(). Some
> +      architectures can optimize lockless page table operations if
> +      this is enabled.
> +
> endmenu
> -- 
> 2.20.1