Re: [RFC][PATCH 1/3] mm/debug-pagealloc.c: Split out page poisoning from debug page_alloc

[Jianyu Zhan]

On Tue, Jan 26, 2016 at 12:55 AM, Laura Abbott
<labbott@xxxxxxxxxxxxxxxxx> wrote:
> +static bool __page_poisoning_enabled __read_mostly;
> +static bool want_page_poisoning __read_mostly =
> +       !IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC);
> +


I would say this patch is nice with regard to decoupling
CONFIG_DEBUG_PAGEALLOC and CONFIG_PAGE_POISONING.

But  since when we enable CONFIG_DEBUG_PAGEALLOC,
CONFIG_PAGE_POISONING will be selected.

So it would be better to make page_poison.c totally
CONFIG_DEBUG_PAGEALLOC agnostic,  in case we latter have
more PAGE_POISONING users(currently only DEBUG_PAGEALLOC ). How about like this:

+static bool want_page_poisoning __read_mostly =
+       !IS_ENABLED(CONFIG_PAGE_POISONING );

Or just let it default to 'true',  since we only compile this
page_poison.c when we enable CONFIG_PAGE_POISONING.


Thanks,
Jianyu Zhan