Messages in this thread | | | Date | Sun, 2 Sep 2012 23:17:18 -0700 | Subject | Re: [PATCH -v2 13/13] x86, 64bit: Map first 1M ram early before memblock_x86_fill() | From | Yinghai Lu <> |
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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.
> >> +RESERVE_BRK(early_pgt_alloc, 65536); > > What is this needed for?
for extra page table, and extend_brk will consume that.
> >> +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
> > 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 ?
Thanks
Yinghai
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