[PATCH V3] mm: Support memblock alloc on the exact node for sparse_buffer_init()

From: Yunfeng Ye
Date: Wed Sep 25 2019 - 03:19:08 EST


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@xxxxxxxxxx>
---
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 zero, 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