This patch modifies the memblock_find_in_range_node() to support two
different allocation orders. After this patch, memblock will check
memblock.current_order, and decide in which order to allocate memory.
Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
Reviewed-by: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
---
mm/memblock.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++---------
1 files changed, 75 insertions(+), 15 deletions(-)
diff --git a/mm/memblock.c b/mm/memblock.c
index 8f1e2d4..961d4a5 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -85,6 +85,77 @@ static long __init_memblock memblock_overlaps_region(struct memblock_type *type,
}
/**
+ * __memblock_find_range - find free area utility
+ * @start: start of candidate range, can be %MEMBLOCK_ALLOC_ACCESSIBLE
+ * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
+ * @size: size of free area to find
+ * @align: alignment of free area to find
+ * @nid: nid of the free area to find, %MAX_NUMNODES for any node
+ *
+ * Utility called from memblock_find_in_range_node(), find free area from
+ * lower address to higher address.
+ *
+ * RETURNS:
+ * Found address on success, %0 on failure.
+ */
+phys_addr_t __init_memblock
+__memblock_find_range(phys_addr_t start, phys_addr_t end,
+ phys_addr_t size, phys_addr_t align, int nid)
+{
+ phys_addr_t this_start, this_end, cand;
+ u64 i;
+
+ for_each_free_mem_range(i, nid, &this_start, &this_end, NULL) {
+ this_start = clamp(this_start, start, end);
+ this_end = clamp(this_end, start, end);
+
+ cand = round_up(this_start, align);
+ if (cand < this_end && this_end - cand >= size)
+ return cand;
+ }
+ return 0;
+}
+
+/**
+ * __memblock_find_range_rev - find free area utility, in reverse order
+ * @start: start of candidate range, can be %MEMBLOCK_ALLOC_ACCESSIBLE
+ * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
+ * @size: size of free area to find
+ * @align: alignment of free area to find
+ * @nid: nid of the free area to find, %MAX_NUMNODES for any node
+ *
+ * Utility called from memblock_find_in_range_node(), find free area from
+ * higher address to lower address.
+ *
+ * RETURNS:
+ * Found address on success, %0 on failure.
+ */
+phys_addr_t __init_memblock
+__memblock_find_range_rev(phys_addr_t start, phys_addr_t end,
+ phys_addr_t size, phys_addr_t align, int nid)
+{
+ phys_addr_t this_start, this_end, cand;
+ u64 i;
+
+ for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
+ this_start = clamp(this_start, start, end);
+ this_end = clamp(this_end, start, end);
+
+ /*
+ * Just in case that (this_end - size) underflows and cause
+ * (cand >= this_start) to be true incorrectly.
+ */
+ if (this_end < size)
+ break;
+
+ cand = round_down(this_end - size, align);
+ if (cand >= this_start)
+ return cand;
+ }
+ return 0;
+}
+
+/**
* memblock_find_in_range_node - find free area in given range and node
* @start: start of candidate range, can be %MEMBLOCK_ALLOC_ACCESSIBLE
* @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
@@ -110,9 +181,6 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
phys_addr_t end, phys_addr_t size,
phys_addr_t align, int nid)
{
- phys_addr_t this_start, this_end, cand;
- u64 i;
-
/* pump up @start and @end */
if (start == MEMBLOCK_ALLOC_ACCESSIBLE)
start = memblock.current_limit_low;
@@ -123,18 +191,10 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
start = max_t(phys_addr_t, start, PAGE_SIZE);
end = max(start, end);
- for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
- this_start = clamp(this_start, start, end);
- this_end = clamp(this_end, start, end);
-
- if (this_end < size)
- continue;
-
- cand = round_down(this_end - size, align);
- if (cand >= this_start)
- return cand;
- }
- return 0;
+ if (memblock.current_order == MEMBLOCK_ORDER_DEFAULT)
+ return __memblock_find_range_rev(start, end, size, align, nid);
+ else
+ return __memblock_find_range(start, end, size, align, nid);
}
/**
--
1.7.1
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