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Subject[PATCH v2 1/4] mm/memblock: reduce overhead in binary search
Date
"v1 -> v2": 
* move check from memblock_search to memblock_is_memory
* modify changelog

When checking the indicated address belongs to the memory region, the
memory regions are checked one by one through binary search, which would
be a little time consuming. If the indicated address isn't in memory
region, then we needn't do the time-sonsuming search. The patch adds
more check on the indicated address for that purpose.

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
mm/memblock.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 4d9393c..258e81d 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -888,6 +888,11 @@ int __init memblock_is_reserved(phys_addr_t addr)

int __init_memblock memblock_is_memory(phys_addr_t addr)
{
+
+ if (unlikely(addr < memblock_start_of_DRAM() ||
+ addr >= memblock_end_of_DRAM()))
+ return 0;
+
return memblock_search(&memblock.memory, addr) != -1;
}

--
1.7.5.4


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