Re: [PATCH] mm, page_alloc: really disable DEBUG_PAGEALLOC with hibernation

[Vlastimil Babka <vbabka@suse.cz>]

On 5/19/21 5:28 PM, Krzysztof Kozlowski wrote:
> The documentation of DEBUG_PAGEALLOC states that it cannot be used with
> hibernation, however the Kconfig entry would allow it if
> ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC.
> 
> Fixes: ee3b4290aec0 ("generic debug pagealloc: build fix")
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

Hmm the documentation seems wrong, as going through history it was indeed in
conflict only on PPC and SPARC.

> ---
>  mm/Kconfig.debug | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
> index 1e73717802f8..0ace5b2a9d04 100644
> --- a/mm/Kconfig.debug
> +++ b/mm/Kconfig.debug
> @@ -11,7 +11,7 @@ config PAGE_EXTENSION
>  config DEBUG_PAGEALLOC
>  	bool "Debug page memory allocations"
>  	depends on DEBUG_KERNEL
> -	depends on !HIBERNATION || ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC
> +	depends on !HIBERNATION && ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC
>  	select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC
>  	help
>  	  Unmap pages from the kernel linear mapping after free_pages().
>