On Wed, Sep 18, 2019 at 03:08:41PM +0800, Yunfeng Ye wrote: > > >On 2019/9/18 14:51, Wei Yang wrote: >> 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. >>> >> >> Looks this changes current behavior even it fall back to section based >> allocation. >> >When fall back to section allocation, it still use %MEMBLOCK_ALLOC_ACCESSIBLE >,I think the behavior is not change, Can you tell me the detail about the >changes. thanks. > You pass MEMBLOCK_ALLOC_EXACT_NODE for the first round allocation, which forbid it allocates from other node. This is different from current behavior. Am I right?
