Messages in this thread | | | Date | Mon, 3 Sep 2012 08:50:01 +0300 | Subject | Re: [PATCH -v2 13/13] x86, 64bit: Map first 1M ram early before memblock_x86_fill() | From | Pekka Enberg <> |
| |
On Sun, Sep 2, 2012 at 10:46 AM, Yinghai Lu <yinghai@kernel.org> wrote: > This one intend to fix bugs: > when efi booting have too many memmap entries, will need to double memblock > memory array or reserved array.
Okay, why do we need to do that?
> +RESERVE_BRK(early_pgt_alloc, 65536);
What is this needed for?
> +void __init early_init_mem_mapping(void) > +{ > + unsigned long tables; > + phys_addr_t base; > + unsigned long start = 0, end = ISA_END_ADDRESS; > + > + probe_page_size_mask(); > + > + if (max_pfn_mapped) > + return;
I find this confusing - what is this protecting for? Why is 'max_pfn_mapped' set when someone calls early_init_mem_mappings()?
Side note: we have multiple "pfn_mapped" globals and it's not at all obvious to me what the semantics for them are. Maybe adding a comment or two in arch/x86/include/asm/page_types.h would help.
> + > + tables = calculate_table_space_size(start, end); > + base = __pa(extend_brk(tables, PAGE_SIZE)); > +
| |