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-rw-r--r--arch/x86/mm/init_64.c34
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.