memblock, numa: binary search node id
Current early_pfn_to_nid() on arch that support memblock go over
memblock.memory one by one, so will take too many try near the end.
We can use existing memblock_search to find the node id for given pfn,
that could save some time on bigger system that have many entries
memblock.memory array.
Here are the timing differences for several machines. In each case with
the patch less time was spent in __early_pfn_to_nid().
3.11-rc5 with patch difference (%)
-------- ---------- --------------
UV1: 256 nodes 9TB: 411.66 402.47 -9.19 (2.23%)
UV2: 255 nodes 16TB: 1141.02 1138.12 -2.90 (0.25%)
UV2: 64 nodes 2TB: 128.15 126.53 -1.62 (1.26%)
UV2: 32 nodes 2TB: 121.87 121.07 -0.80 (0.66%)
Time in seconds.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memblock.c b/mm/memblock.c
index a847bfe6..0ac412a 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -914,6 +914,24 @@
return memblock_search(&memblock.memory, addr) != -1;
}
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+int __init_memblock memblock_search_pfn_nid(unsigned long pfn,
+ unsigned long *start_pfn, unsigned long *end_pfn)
+{
+ struct memblock_type *type = &memblock.memory;
+ int mid = memblock_search(type, (phys_addr_t)pfn << PAGE_SHIFT);
+
+ if (mid == -1)
+ return -1;
+
+ *start_pfn = type->regions[mid].base >> PAGE_SHIFT;
+ *end_pfn = (type->regions[mid].base + type->regions[mid].size)
+ >> PAGE_SHIFT;
+
+ return type->regions[mid].nid;
+}
+#endif
+
/**
* memblock_is_region_memory - check if a region is a subset of memory
* @base: base of region to check