Hi,
On Wed, Sep 18, 2019 at 12:22:29PM +0800, Yunfeng Ye wrote:
> Currently, when memblock_find_in_range_node() fail on the exact node, it
> will use %NUMA_NO_NODE to find memblock from other nodes. At present,
> the work is good, but when the large memory is insufficient and the
> small memory is enough, we want to allocate the small memory of this
> node first, and do not need to allocate large memory from other nodes.
>
> In sparse_buffer_init(), it will prepare large chunks of memory for page
> structure. The page management structure requires a lot of memory, but
> if the node does not have enough memory, it can be converted to a small
> memory allocation without having to allocate it from other nodes.
>
> Add %MEMBLOCK_ALLOC_EXACT_NODE flag for this situation. Normally, the
> behavior is the same with %MEMBLOCK_ALLOC_ACCESSIBLE, only that it will
> not allocate from other nodes when a single node fails to allocate.
>
> If large contiguous block memory allocated fail in sparse_buffer_init(),
> it will allocates small block memmory section by section later.
Did you see the sparse_buffer_init() actually falling back to allocate from a
different node? If a node does not have enough memory to hold it's own
memory map, filling only it with parts of the memory map will not make such
node usable.
> Signed-off-by: Yunfeng Ye <yeyunfeng@xxxxxxxxxx>
> ---
> include/linux/memblock.h | 1 +
> mm/memblock.c | 3 ++-
> mm/sparse.c | 2 +-
> 3 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index f491690..9a81d9c 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -339,6 +339,7 @@ static inline int memblock_get_region_node(const struct memblock_region *r)
> #define MEMBLOCK_ALLOC_ANYWHERE (~(phys_addr_t)0)
> #define MEMBLOCK_ALLOC_ACCESSIBLE 0
> #define MEMBLOCK_ALLOC_KASAN 1
> +#define MEMBLOCK_ALLOC_EXACT_NODE 2
>
> /* We are using top down, so it is safe to use 0 here */
> #define MEMBLOCK_LOW_LIMIT 0
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 7d4f61a..dbd52c3c 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -277,6 +277,7 @@ static phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size,
>
> /* pump up @end */
> if (end == MEMBLOCK_ALLOC_ACCESSIBLE ||
> + end == MEMBLOCK_ALLOC_EXACT_NODE ||
> end == MEMBLOCK_ALLOC_KASAN)
> end = memblock.current_limit;
>
> @@ -1365,7 +1366,7 @@ 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 (end != MEMBLOCK_ALLOC_EXACT_NODE && nid != NUMA_NO_NODE) {
> found = memblock_find_in_range_node(size, align, start,
> end, NUMA_NO_NODE,
> flags);
> diff --git a/mm/sparse.c b/mm/sparse.c
> index 72f010d..828db46 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c
> @@ -477,7 +477,7 @@ static void __init sparse_buffer_init(unsigned long size, int nid)
> sparsemap_buf =
> memblock_alloc_try_nid_raw(size, PAGE_SIZE,
> addr,
> - MEMBLOCK_ALLOC_ACCESSIBLE, nid);
> + MEMBLOCK_ALLOC_EXACT_NODE, nid);
> sparsemap_buf_end = sparsemap_buf + size;
> }
>
> --
> 2.7.4.huawei.3
>
>
--
Sincerely yours,
Mike.
