bbfceef47f
This patch adds in the necessary support for sparsemem such that x86-64 kernels may use sparsemem as an alternative to discontigmem for NUMA kernels. Note that this does no preclude one from continuing to build NUMA kernels using discontigmem, but merely allows the option to build NUMA kernels with sparsemem. Interestingly, the use of sparsemem in lieu of discontigmem in NUMA kernels results in reduced text size for otherwise equivalent kernels as shown in the example builds below: text data bss dec hex filename 2371036 765884 1237108 4374028 42be0c vmlinux.discontig 2366549 776484 1302772 4445805 43d66d vmlinux.sparse Signed-off-by: Matt Tolentino <matthew.e.tolentino@intel.com> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
26 lines
678 B
C
26 lines
678 B
C
#ifndef _ASM_X86_64_SPARSEMEM_H
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#define _ASM_X86_64_SPARSEMEM_H 1
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#ifdef CONFIG_SPARSEMEM
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/*
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* generic non-linear memory support:
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*
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* 1) we will not split memory into more chunks than will fit into the flags
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* field of the struct page
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*
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* SECTION_SIZE_BITS 2^n: size of each section
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* MAX_PHYSADDR_BITS 2^n: max size of physical address space
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* MAX_PHYSMEM_BITS 2^n: how much memory we can have in that space
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*
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*/
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#define SECTION_SIZE_BITS 27 /* matt - 128 is convenient right now */
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#define MAX_PHYSADDR_BITS 40
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#define MAX_PHYSMEM_BITS 40
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extern int early_pfn_to_nid(unsigned long pfn);
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#endif /* CONFIG_SPARSEMEM */
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#endif /* _ASM_X86_64_SPARSEMEM_H */
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