On 19/05/2021 11:48, Vlastimil Babka wrote: > On 5/19/21 5:30 PM, David Hildenbrand wrote: >> On 19.05.21 17:28, 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@xxxxxxxxxxxxx> >>> --- >>> 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(). >>> >> >> I remember this should be working now, as we temporarily map the pages in the >> direct map when hibernating? > > Yeah, and if the problem was the page poisoning based implementation/fallback, > that was also fixed. > > The current dependencies come from the unification by ee3b4290aec03 > > The question is if PPC and SPARC still really need to disable hibernation. I tested slightly older kernel (v5.8 with few backports for poison support with hibernation) and it worked fine on x86_64. For the PPC and SPARC I don't know. I can update the Kconfig option description to mention x86_64. Best regards, Krzysztof