14045ebf1e
The kernel address space of a 64 bit kernel currently uses a three level page table and the vmemmap array has a fixed address and a fixed maximum size. A three level page table is good enough for systems with less than 3.8TB of memory, for bigger systems four page table levels need to be used. Each page table level costs a bit of performance, use 3 levels for normal systems and 4 levels only for the really big systems. To avoid bloating sparse.o too much set MAX_PHYSMEM_BITS to 46 for a maximum of 64TB of memory. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
19 lines
325 B
C
19 lines
325 B
C
#ifndef _ASM_S390_SPARSEMEM_H
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#define _ASM_S390_SPARSEMEM_H
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#ifdef CONFIG_64BIT
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#define SECTION_SIZE_BITS 28
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#define MAX_PHYSADDR_BITS 46
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#define MAX_PHYSMEM_BITS 46
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#else
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#define SECTION_SIZE_BITS 25
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#define MAX_PHYSADDR_BITS 31
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#define MAX_PHYSMEM_BITS 31
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#endif /* CONFIG_64BIT */
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#endif /* _ASM_S390_SPARSEMEM_H */
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