Messages in this thread | | | Date | Mon, 3 Sep 2012 09:26:46 +0300 | Subject | Re: [PATCH -v2 13/13] x86, 64bit: Map first 1M ram early before memblock_x86_fill() | From | Pekka Enberg <> |
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On Mon, Sep 3, 2012 at 9:17 AM, Yinghai Lu <yinghai@kernel.org> wrote: > On Sun, Sep 2, 2012 at 10:50 PM, Pekka Enberg <penberg@kernel.org> wrote: >> 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? > > memblock initial memory only have 128 entry, and some EFI system could > have more entries than that. > > So during memblock_x86_fill need to double that array. > > and efi_reserve_boot_services() could make thing more worse. aka need > more entries in memblock.memory.regions.
Aah. Care to put that information in the changelog?
>>> +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()? > > for 32 bit, it will non zero max_pfn_mapped set in head_32.S
OK, that's why my grep missed it. A comment would be nice.
>> 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. > > move the comments from arch/x86/kernel/setup.c to that header file ?
Yup, or move the globals together with the comment to arch/x86/mm/init.c.
That said, max_pfn_high_mapped really ought to be kept together with the other "pfn_mapped" globals and the comment should be updated.
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