Messages in this thread | | | Subject | Re: [PATCH 1/4] mm/page_alloc: always initialize memory map for the holes | From | David Hildenbrand <> | Date | Wed, 25 Aug 2021 14:11:23 +0200 |
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On 14.07.21 14:37, Mike Rapoport wrote: > From: Mike Rapoport <rppt@linux.ibm.com> > > Currently memory map for the holes is initialized only when SPARSEMEM > memory model is used. Yet, even with FLATMEM there could be holes in the > physical memory layout that have memory map entries. > > For instance, the memory reserved using e820 API on i386 or > "reserved-memory" nodes in device tree would not appear in memblock.memory > and hence the struct pages for such holes will be skipped during memory map > initialization. > > These struct pages will be zeroed because the memory map for FLATMEM > systems is allocated with memblock_alloc_node() that clears the allocated > memory. While zeroed struct pages do not cause immediate problems, the > correct behaviour is to initialize every page using __init_single_page(). > Besides, enabling page poison for FLATMEM case will trigger > PF_POISONED_CHECK() unless the memory map is properly initialized. > > Make sure init_unavailable_range() is called for both SPARSEMEM and FLATMEM > so that struct pages representing memory holes would appear as PG_Reserved > with any memory layout. > > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> > --- > mm/page_alloc.c | 8 -------- > 1 file changed, 8 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 3b97e17806be..878d7af4403d 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -6624,7 +6624,6 @@ static void __meminit zone_init_free_lists(struct zone *zone) > } > } > > -#if !defined(CONFIG_FLATMEM) > /* > * Only struct pages that correspond to ranges defined by memblock.memory > * are zeroed and initialized by going through __init_single_page() during > @@ -6669,13 +6668,6 @@ static void __init init_unavailable_range(unsigned long spfn, > pr_info("On node %d, zone %s: %lld pages in unavailable ranges", > node, zone_names[zone], pgcnt); > } > -#else > -static inline void init_unavailable_range(unsigned long spfn, > - unsigned long epfn, > - int zone, int node) > -{ > -} > -#endif > > static void __init memmap_init_zone_range(struct zone *zone, > unsigned long start_pfn, >
Acked-by: David Hildenbrand <david@redhat.com>
-- Thanks,
David / dhildenb
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