[PATCH 1/2] mm/memblock: cleanup on duplicate VA/PA conversion

[Gavin Shan <shangw@linux.vnet.ibm.com>]

The overall memblock has been organized into the memory regions
and reserved regions. Initially, the memory regions and reserved
regions are stored in the predetermined arrays of "struct memblock
_region". It's possible for the arrays to be enlarged when we have
newly added regions for them, but no enough space there. Under the
situation, We will created double-sized array to meet the requirement.
However, the original implementation converted the VA (Virtual Address)
of the newly allocated array of regions to PA (Physical Address), then
translate back when we allocates the new array from slab. That's
actually unnecessary.

The patch removes the duplicate VA/PA conversion.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
---
 mm/memblock.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index a44eab3..eae06ea 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -212,14 +212,15 @@ static int __init_memblock memblock_double_array(struct memblock_type *type)
 	if (use_slab) {
 		new_array = kmalloc(new_size, GFP_KERNEL);
 		addr = new_array ? __pa(new_array) : 0;
-	} else
+	} else {
 		addr = memblock_find_in_range(0, MEMBLOCK_ALLOC_ACCESSIBLE, new_size, sizeof(phys_addr_t));
+		new_array = addr ? __va(addr) : 0;
+	}
 	if (!addr) {
 		pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
 		       memblock_type_name(type), type->max, type->max * 2);
 		return -1;
 	}
-	new_array = __va(addr);
 
 	memblock_dbg("memblock: %s array is doubled to %ld at [%#010llx-%#010llx]",
 		 memblock_type_name(type), type->max * 2, (u64)addr, (u64)addr + new_size - 1);
-- 
1.7.9.5

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