On 6/3/21 11:49 PM, Mike Rapoport wrote: > From: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > Arc does not use DISCONTIGMEM to implement high memory, update the comment > describing how high memory works to reflect this. > > Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Acked-by: Vineet Gupta <vgupta@xxxxxxxxxxxx> Thx, -Vineet > --- > arch/arc/mm/init.c | 13 +++++-------- > 1 file changed, 5 insertions(+), 8 deletions(-) > > diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c > index e2ed355438c9..397a201adfe3 100644 > --- a/arch/arc/mm/init.c > +++ b/arch/arc/mm/init.c > @@ -139,16 +139,13 @@ void __init setup_arch_memory(void) > > #ifdef CONFIG_HIGHMEM > /* > - * Populate a new node with highmem > - * > * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) > - * than addresses in normal ala low memory (0x8000_0000 based). > + * than addresses in normal aka low memory (0x8000_0000 based). > * Even with PAE, the huge peripheral space hole would waste a lot of > - * mem with single mem_map[]. This warrants a mem_map per region design. > - * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM. > - * > - * DISCONTIGMEM in turns requires multiple nodes. node 0 above is > - * populated with normal memory zone while node 1 only has highmem > + * mem with single contiguous mem_map[]. > + * Thus when HIGHMEM on ARC is enabled the memory map corresponding > + * to the hole is freed and ARC specific version of pfn_valid() > + * handles the hole in the memory map. > */ > #ifdef CONFIG_DISCONTIGMEM > node_set_online(1);
