diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/mm/init_64.c | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index f35c66c5959a..b92591fa8970 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1230,17 +1230,43 @@ const char *arch_vma_name(struct vm_area_struct *vma) return NULL; } -#ifdef CONFIG_X86_UV -unsigned long memory_block_size_bytes(void) +static unsigned long probe_memory_block_size(void) { + /* start from 2g */ + unsigned long bz = 1UL<<31; + +#ifdef CONFIG_X86_UV if (is_uv_system()) { printk(KERN_INFO "UV: memory block size 2GB\n"); return 2UL * 1024 * 1024 * 1024; } - return MIN_MEMORY_BLOCK_SIZE; -} #endif + /* less than 64g installed */ + if ((max_pfn << PAGE_SHIFT) < (16UL << 32)) + return MIN_MEMORY_BLOCK_SIZE; + + /* get the tail size */ + while (bz > MIN_MEMORY_BLOCK_SIZE) { + if (!((max_pfn << PAGE_SHIFT) & (bz - 1))) + break; + bz >>= 1; + } + + printk(KERN_DEBUG "memory block size : %ldMB\n", bz >> 20); + + return bz; +} + +static unsigned long memory_block_size_probed; +unsigned long memory_block_size_bytes(void) +{ + if (!memory_block_size_probed) + memory_block_size_probed = probe_memory_block_size(); + + return memory_block_size_probed; +} + #ifdef CONFIG_SPARSEMEM_VMEMMAP /* * Initialise the sparsemem vmemmap using huge-pages at the PMD level. |