Suppose, memblock_alloc_ranged_nid with highmem_start is success
when cma_declare_contiguous_nid is called with !fixed
in the system 32-bit system with PHYS_ADDR_T_64BIT enabled
with memblock.bottom_up == false.
But, Next trial to memblock_alloc_range_nid to allocate in
[SIZE_4G, limits) nullifies former success allocated addr and
it retries to memblock_alloc_ragne_nid again.
In this situation, first success address area is lost.
By changing order of allocation (SIZE_4G, high_memory and base) and
checking whether allocated prevents potential memory lost.
Signed-off-by: Levi Yun <ppbuk5246@xxxxxxxxx>
---
mm/cma.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/mm/cma.c b/mm/cma.c
index 4a978e09547a..49d9b08d9a47 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -321,18 +321,6 @@ int __init cma_declare_contiguous_nid(phys_addr_t base,
} else {
phys_addr_t addr = 0;
- /*
- * All pages in the reserved area must come from the same zone.
- * If the requested region crosses the low/high memory boundary,
- * try allocating from high memory first and fall back to low
- * memory in case of failure.
- */
- if (base < highmem_start && limit > highmem_start) {
- addr = memblock_alloc_range_nid(size, alignment,
- highmem_start, limit, nid, true);
- limit = highmem_start;
- }
-
/*
* If there is enough memory, try a bottom-up allocation first.
* It will place the new cma area close to the start of the node
@@ -350,6 +338,18 @@ int __init cma_declare_contiguous_nid(phys_addr_t base,
}
#endif
+ /*
+ * All pages in the reserved area must come from the same zone.
+ * If the requested region crosses the low/high memory boundary,
+ * try allocating from high memory first and fall back to low
+ * memory in case of failure.
+ */
+ if (!addr && base < highmem_start && limit > highmem_start) {
+ addr = memblock_alloc_range_nid(size, alignment,
+ highmem_start, limit, nid, true);
+ limit = highmem_start;
+ }
+
if (!addr) {
addr = memblock_alloc_range_nid(size, alignment, base,
limit, nid, true);
--
2.35.1
