On Sat, Mar 30, 2019 at 09:13:46PM +0800, Muchun Song wrote: > When we not use flat memory, the mem_map will be NULL and > pfn_to_page(max_pfn) is a pointer which is located in kernel space. So > max_mapnr is assigned a very large number(e.g., 0xffffxxxx_xxxxxxxx) - fix > it. > > Signed-off-by: Muchun Song <smuc...@gmail.com> > --- > arch/arm64/mm/init.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index bc02818fa48b..e86c21a44c88 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -535,7 +535,7 @@ void __init mem_init(void) > else > swiotlb_force = SWIOTLB_NO_FORCE; > > - set_max_mapnr(pfn_to_page(max_pfn) - mem_map); > + set_max_mapnr(max_pfn - PHYS_PFN_OFFSET); > > #ifndef CONFIG_SPARSEMEM_VMEMMAP > free_unused_memmap();
The patch looks fine but did you actually hit any problem? max_mapnr seems to only be used in the generic pfn_valid() which we do not use on arm64 (just wondering if it needs a cc stable; it doesn't look like as it's not a regression). -- Catalin
