Messages in this thread | | | Subject | Re: [PATCH v4 3/4] arch, mm: restore dependency of __kernel_map_pages() of DEBUG_PAGEALLOC | From | Vlastimil Babka <> | Date | Wed, 4 Nov 2020 19:02:20 +0100 |
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On 11/3/20 5:20 PM, Mike Rapoport wrote: > From: Mike Rapoport <rppt@linux.ibm.com>
Subject should have "on DEBUG_PAGEALLOC" ?
> The design of DEBUG_PAGEALLOC presumes that __kernel_map_pages() must never > fail. With this assumption is wouldn't be safe to allow general usage of > this function. > > Moreover, some architectures that implement __kernel_map_pages() have this > function guarded by #ifdef DEBUG_PAGEALLOC and some refuse to map/unmap > pages when page allocation debugging is disabled at runtime. > > As all the users of __kernel_map_pages() were converted to use > debug_pagealloc_map_pages() it is safe to make it available only when > DEBUG_PAGEALLOC is set. > > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> > Acked-by: David Hildenbrand <david@redhat.com> > Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > --- > arch/Kconfig | 3 +++ > arch/arm64/Kconfig | 4 +--- > arch/arm64/mm/pageattr.c | 8 ++++++-- > arch/powerpc/Kconfig | 5 +---- > arch/riscv/Kconfig | 4 +--- > arch/riscv/include/asm/pgtable.h | 2 -- > arch/riscv/mm/pageattr.c | 2 ++ > arch/s390/Kconfig | 4 +--- > arch/sparc/Kconfig | 4 +--- > arch/x86/Kconfig | 4 +--- > arch/x86/mm/pat/set_memory.c | 2 ++ > include/linux/mm.h | 10 +++++++--- > 12 files changed, 26 insertions(+), 26 deletions(-) > > diff --git a/arch/Kconfig b/arch/Kconfig > index 56b6ccc0e32d..56d4752b6db6 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -1028,6 +1028,9 @@ config HAVE_STATIC_CALL_INLINE > bool > depends on HAVE_STATIC_CALL > > +config ARCH_SUPPORTS_DEBUG_PAGEALLOC > + bool > + > source "kernel/gcov/Kconfig" > > source "scripts/gcc-plugins/Kconfig" > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 1d466addb078..a932810cfd90 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -71,6 +71,7 @@ config ARM64 > select ARCH_USE_QUEUED_RWLOCKS > select ARCH_USE_QUEUED_SPINLOCKS > select ARCH_USE_SYM_ANNOTATIONS > + select ARCH_SUPPORTS_DEBUG_PAGEALLOC > select ARCH_SUPPORTS_MEMORY_FAILURE > select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK > select ARCH_SUPPORTS_ATOMIC_RMW > @@ -1025,9 +1026,6 @@ config HOLES_IN_ZONE > > source "kernel/Kconfig.hz" > > -config ARCH_SUPPORTS_DEBUG_PAGEALLOC > - def_bool y > - > config ARCH_SPARSEMEM_ENABLE > def_bool y > select SPARSEMEM_VMEMMAP_ENABLE > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > index 1b94f5b82654..439325532be1 100644 > --- a/arch/arm64/mm/pageattr.c > +++ b/arch/arm64/mm/pageattr.c > @@ -155,7 +155,7 @@ int set_direct_map_invalid_noflush(struct page *page) > .clear_mask = __pgprot(PTE_VALID), > }; > > - if (!rodata_full) > + if (!debug_pagealloc_enabled() && !rodata_full) > return 0; > > return apply_to_page_range(&init_mm, > @@ -170,7 +170,7 @@ int set_direct_map_default_noflush(struct page *page) > .clear_mask = __pgprot(PTE_RDONLY), > }; > > - if (!rodata_full) > + if (!debug_pagealloc_enabled() && !rodata_full) > return 0; > > return apply_to_page_range(&init_mm,
I don't understand these two hunks. Previous patch calls this for hibernation when CONFIG_ARCH_HAS_SET_DIRECT_MAP, which is true for arm64. Why suddenly this starts to depend on debug_pagealloc_enabled()?
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