The memblock array is in ascending order and we traverse the memblock array in
reverse order so we can add some simple check to reduce the search work.
Tejun fix a underflow bug in 5d53cb27d8, but I think we could break there for
the same reason.
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Lin Feng <linfeng@xxxxxxxxxxxxxx>
---
mm/memblock.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/mm/memblock.c b/mm/memblock.c
index 6259055..a710557 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -111,11 +111,18 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
end = max(start, end);
for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
+ /*
+ * exclude the regions out of the candidate range, since it's
+ * likely to find a suitable range, we ignore the worst case.
+ */
+ if (this_start >= end)
+ continue;
+
this_start = clamp(this_start, start, end);
this_end = clamp(this_end, start, end);
if (this_end < size)
- continue;
+ break;
cand = round_down(this_end - size, align);
if (cand >= this_start)
--
1.7.11.7
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