[PATCH V4] mm: Support memblock alloc on the exact node for sparse_buffer_init()

[PATCH V4] mm: Support memblock alloc on the exact node for sparse_buffer_init()

[Yunfeng Ye]

sparse_buffer_init() use memblock_alloc_try_nid_raw() to allocate memory
for page management structure, if memory allocation fails from specified
node, it will fall back to allocate from other nodes.

Normally, the page management structure will not exceed 2% of the total
memory, but a large continuous block of allocation is needed. In most
cases, memory allocation from the specified node will success always,
but a node memory become highly fragmented will fail. we expect to
allocate memory base section rather than by allocating a large block of
memory from other NUMA nodes

Add memblock_alloc_exact_nid_raw() for this situation, which allocate
boot memory block on the exact node. If a large contiguous block memory
allocate fail in sparse_buffer_init(), it will fall back to allocate
small block memory base section.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
---
v3 -> v4:
 - add Reviewed-by
 - modify the comment "@exact_nid is false" instead of "@exact_nid is zero"

v2 -> v3:
 - use "bool exact_nid" instead of "int need_exact_nid"
 - remove the comment "without panicking"

v1 -> v2:
 - use memblock_alloc_exact_nid_raw() rather than using a flag

 include/linux/memblock.h |  3 +++
 mm/memblock.c            | 65 ++++++++++++++++++++++++++++++++++++++++--------
 mm/sparse.c              |  2 +-
 3 files changed, 58 insertions(+), 12 deletions(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index f491690..b38bbef 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -358,6 +358,9 @@ static inline phys_addr_t memblock_phys_alloc(phys_addr_t size,
 					 MEMBLOCK_ALLOC_ACCESSIBLE);
 }

+void *memblock_alloc_exact_nid_raw(phys_addr_t size, phys_addr_t align,
+				 phys_addr_t min_addr, phys_addr_t max_addr,
+				 int nid);
 void *memblock_alloc_try_nid_raw(phys_addr_t size, phys_addr_t align,
 				 phys_addr_t min_addr, phys_addr_t max_addr,
 				 int nid);
diff --git a/mm/memblock.c b/mm/memblock.c
index 7d4f61a..0de9d83 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1323,12 +1323,13 @@ __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,
  * @start: the lower bound of the memory region to allocate (phys address)
  * @end: the upper bound of the memory region to allocate (phys address)
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
+ * @exact_nid: control the allocation fall back to other nodes
  *
  * The allocation is performed from memory region limited by
  * memblock.current_limit if @max_addr == %MEMBLOCK_ALLOC_ACCESSIBLE.
  *
- * If the specified node can not hold the requested memory the
- * allocation falls back to any node in the system
+ * If the specified node can not hold the requested memory and @exact_nid
+ * is false, the allocation falls back to any node in the system
  *
  * For systems with memory mirroring, the allocation is attempted first
  * from the regions with mirroring enabled and then retried from any
@@ -1342,7 +1343,8 @@ __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,
  */
 static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
 					phys_addr_t align, phys_addr_t start,
-					phys_addr_t end, int nid)
+					phys_addr_t end, int nid,
+					bool exact_nid)
 {
 	enum memblock_flags flags = choose_memblock_flags();
 	phys_addr_t found;
@@ -1365,7 +1367,7 @@ static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
 	if (found && !memblock_reserve(found, size))
 		goto done;

-	if (nid != NUMA_NO_NODE) {
+	if (nid != NUMA_NO_NODE && !exact_nid) {
 		found = memblock_find_in_range_node(size, align, start,
 						    end, NUMA_NO_NODE,
 						    flags);
@@ -1413,7 +1415,8 @@ phys_addr_t __init memblock_phys_alloc_range(phys_addr_t size,
 					     phys_addr_t start,
 					     phys_addr_t end)
 {
-	return memblock_alloc_range_nid(size, align, start, end, NUMA_NO_NODE);
+	return memblock_alloc_range_nid(size, align, start, end, NUMA_NO_NODE,
+					false);
 }

 /**
@@ -1432,7 +1435,7 @@ phys_addr_t __init memblock_phys_alloc_range(phys_addr_t size,
 phys_addr_t __init memblock_phys_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
 {
 	return memblock_alloc_range_nid(size, align, 0,
-					MEMBLOCK_ALLOC_ACCESSIBLE, nid);
+					MEMBLOCK_ALLOC_ACCESSIBLE, nid, false);
 }

 /**
@@ -1442,6 +1445,7 @@ phys_addr_t __init memblock_phys_alloc_try_nid(phys_addr_t size, phys_addr_t ali
  * @min_addr: the lower bound of the memory region to allocate (phys address)
  * @max_addr: the upper bound of the memory region to allocate (phys address)
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
+ * @exact_nid: control the allocation fall back to other nodes
  *
  * Allocates memory block using memblock_alloc_range_nid() and
  * converts the returned physical address to virtual.
@@ -1457,7 +1461,7 @@ phys_addr_t __init memblock_phys_alloc_try_nid(phys_addr_t size, phys_addr_t ali
 static void * __init memblock_alloc_internal(
 				phys_addr_t size, phys_addr_t align,
 				phys_addr_t min_addr, phys_addr_t max_addr,
-				int nid)
+				int nid, bool exact_nid)
 {
 	phys_addr_t alloc;

@@ -1469,11 +1473,13 @@ static void * __init memblock_alloc_internal(
 	if (WARN_ON_ONCE(slab_is_available()))
 		return kzalloc_node(size, GFP_NOWAIT, nid);

-	alloc = memblock_alloc_range_nid(size, align, min_addr, max_addr, nid);
+	alloc = memblock_alloc_range_nid(size, align, min_addr, max_addr, nid,
+					exact_nid);

 	/* retry allocation without lower limit */
 	if (!alloc && min_addr)
-		alloc = memblock_alloc_range_nid(size, align, 0, max_addr, nid);
+		alloc = memblock_alloc_range_nid(size, align, 0, max_addr, nid,
+						exact_nid);

 	if (!alloc)
 		return NULL;
@@ -1482,6 +1488,43 @@ static void * __init memblock_alloc_internal(
 }

 /**
+ * memblock_alloc_exact_nid_raw - allocate boot memory block on the exact node
+ * without zeroing memory
+ * @size: size of memory block to be allocated in bytes
+ * @align: alignment of the region and block's size
+ * @min_addr: the lower bound of the memory region from where the allocation
+ *	  is preferred (phys address)
+ * @max_addr: the upper bound of the memory region from where the allocation
+ *	      is preferred (phys address), or %MEMBLOCK_ALLOC_ACCESSIBLE to
+ *	      allocate only from memory limited by memblock.current_limit value
+ * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
+ *
+ * Public function, provides additional debug information (including caller
+ * info), if enabled. Does not zero allocated memory.
+ *
+ * Return:
+ * Virtual address of allocated memory block on success, NULL on failure.
+ */
+void * __init memblock_alloc_exact_nid_raw(
+			phys_addr_t size, phys_addr_t align,
+			phys_addr_t min_addr, phys_addr_t max_addr,
+			int nid)
+{
+	void *ptr;
+
+	memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
+		     __func__, (u64)size, (u64)align, nid, &min_addr,
+		     &max_addr, (void *)_RET_IP_);
+
+	ptr = memblock_alloc_internal(size, align,
+					   min_addr, max_addr, nid, true);
+	if (ptr && size > 0)
+		page_init_poison(ptr, size);
+
+	return ptr;
+}
+
+/**
  * memblock_alloc_try_nid_raw - allocate boot memory block without zeroing
  * memory and without panicking
  * @size: size of memory block to be allocated in bytes
@@ -1512,7 +1555,7 @@ void * __init memblock_alloc_try_nid_raw(
 		     &max_addr, (void *)_RET_IP_);

 	ptr = memblock_alloc_internal(size, align,
-					   min_addr, max_addr, nid);
+					   min_addr, max_addr, nid, false);
 	if (ptr && size > 0)
 		page_init_poison(ptr, size);

@@ -1547,7 +1590,7 @@ void * __init memblock_alloc_try_nid(
 		     __func__, (u64)size, (u64)align, nid, &min_addr,
 		     &max_addr, (void *)_RET_IP_);
 	ptr = memblock_alloc_internal(size, align,
-					   min_addr, max_addr, nid);
+					   min_addr, max_addr, nid, false);
 	if (ptr)
 		memset(ptr, 0, size);

diff --git a/mm/sparse.c b/mm/sparse.c
index 72f010d..1a06471 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -475,7 +475,7 @@ static void __init sparse_buffer_init(unsigned long size, int nid)
 	phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
 	WARN_ON(sparsemap_buf);	/* forgot to call sparse_buffer_fini()? */
 	sparsemap_buf =
-		memblock_alloc_try_nid_raw(size, PAGE_SIZE,
+		memblock_alloc_exact_nid_raw(size, PAGE_SIZE,
 						addr,
 						MEMBLOCK_ALLOC_ACCESSIBLE, nid);
 	sparsemap_buf_end = sparsemap_buf + size;
-- 
2.7.4