Messages in this thread | | | Date | Mon, 07 Jan 2008 14:13:52 -0800 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH 1 of 8] x86: page.h: unify constants |
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Andi Kleen wrote: >> + >> +#define LARGE_PAGE_SIZE (_AC(1,UL) << PMD_SHIFT) >> +#define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1)) >> + >> +#define HPAGE_SHIFT PMD_SHIFT >> +#define HPAGE_SIZE (_AC(1,UL) << HPAGE_SHIFT) >> +#define HPAGE_MASK (~(HPAGE_SIZE - 1)) >> +#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) >> > > This will actually stop being the same soon with GB pages which > are only supported on 64bit. >
I was wondering about that. Will you always use GB pages, or will there be two classes of huge pages, or will it be a runtime/compiletime config?
>> + >> +#ifdef CONFIG_X86_64 >> +#define THREAD_ORDER 1 >> +#define THREAD_SIZE (PAGE_SIZE << THREAD_ORDER) >> +#define CURRENT_MASK (~(THREAD_SIZE-1)) >> + >> +#define EXCEPTION_STACK_ORDER 0 >> +#define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER) >> + >> +#define DEBUG_STACK_ORDER (EXCEPTION_STACK_ORDER + 1) >> +#define DEBUG_STKSZ (PAGE_SIZE << DEBUG_STACK_ORDER) >> + >> +#define IRQSTACK_ORDER 2 >> +#define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER) >> > > This all seems hardly 64bit specific (except for THREAD_ORDER > but you can probably handle that in Kconfig or just get rid > of it for 32bit) >
They're only used by 64-bit at the moment, aren't they? Or are you suggesting 32-bit could use them too? There's no corresponding definitions on the 32-bit side at the moment.
>> +#define __PHYSICAL_START CONFIG_PHYSICAL_START >> > > Also not 64bit specific >
It's use is 64-bit specific though, isn't it?
>> +#ifdef CONFIG_X86_PAE >> +#define __PHYSICAL_MASK_SHIFT 36 >> > > I originally added the PHYSICAL_MASK stuff to deal with masking off NX, > but I must admit it wasn't the best idea I ever had. It would be probably > better to just get rid of it and always mask off the high reserved flags bit > explicitely. If you make that 0 then there should be no special > case for PAE. >
Hm, OK. I thought different 64-bit implementations might have different sized physical address spaces or something.
J
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