Re: [PATCH V2 2/2] mm/pgtable/debug: Add test validating architecture page table helpers
From: Kirill A. Shutemov
Date: Fri Sep 13 2019 - 05:13:07 EST
On Fri, Sep 13, 2019 at 02:32:04PM +0530, Anshuman Khandual wrote:
> On 09/12/2019 10:44 PM, Christophe Leroy wrote:
> > Le 12/09/2019 à 08:02, Anshuman Khandual a écrit :
> >> This adds a test module which will validate architecture page table helpers
> >> and accessors regarding compliance with generic MM semantics expectations.
> >> This will help various architectures in validating changes to the existing
> >> page table helpers or addition of new ones.
> >> Test page table and memory pages creating it's entries at various level are
> >> all allocated from system memory with required alignments. If memory pages
> >> with required size and alignment could not be allocated, then all depending
> >> individual tests are skipped.
> > [...]
> >> Suggested-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> >> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> >> ---
> >> arch/x86/include/asm/pgtable_64_types.h | 2 +
> >> mm/Kconfig.debug | 14 +
> >> mm/Makefile | 1 +
> >> mm/arch_pgtable_test.c | 429 ++++++++++++++++++++++++
> >> 4 files changed, 446 insertions(+)
> >> create mode 100644 mm/arch_pgtable_test.c
> >> diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
> >> index 52e5f5f2240d..b882792a3999 100644
> >> --- a/arch/x86/include/asm/pgtable_64_types.h
> >> +++ b/arch/x86/include/asm/pgtable_64_types.h
> >> @@ -40,6 +40,8 @@ static inline bool pgtable_l5_enabled(void)
> >> #define pgtable_l5_enabled() 0
> >> #endif /* CONFIG_X86_5LEVEL */
> >> +#define mm_p4d_folded(mm) (!pgtable_l5_enabled())
> >> +
> > This is specific to x86, should go in a separate patch.
> Thought about it but its just a single line. Kirill suggested this in the
> previous version. There is a generic fallback definition but s390 has it's
> own. This change overrides the generic one for x86 probably as a fix or as
> an improvement. Kirill should be able to help classify it in which case it
> can be a separate patch.
I don't think it worth a separate patch.
Kirill A. Shutemov