From: Wanpeng Li <liwanp@linux.vnet.ibm.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Michal Hocko <mhocko@suse.cz>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Minchan Kim <minchan@kernel.org>,
Gavin Shan <shangw@linux.vnet.ibm.com>,
Wanpeng Li <liwanp@linux.vnet.ibm.com>
Subject: [PATCH v2 1/4] mm/memblock: reduce overhead in binary search
Date: Sun, 26 Aug 2012 17:00:23 +0800 [thread overview]
Message-ID: <1345971626-17090-1-git-send-email-liwanp@linux.vnet.ibm.com> (raw)
"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
next reply other threads:[~2012-08-26 9:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-26 9:00 Wanpeng Li [this message]
2012-08-26 9:00 ` [PATCH v2 2/4] mm/memblock: rename get_allocated_memblock_reserved_regions_info() Wanpeng Li
2012-08-26 9:00 ` [PATCH v2 3/4] mm/memblock: use existing interface to set nid Wanpeng Li
2012-08-26 9:00 ` [PATCH v2 4/4] mm/memblock: cleanup early_node_map[] related comments Wanpeng Li
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