On 01/31/2013 02:19 PM, Simon Jeons wrote:
Hi Tang, On Thu, 2013-01-31 at 11:31 +0800, Tang Chen wrote:Hi Simon, Please see below. :) On 01/31/2013 09:22 AM, Simon Jeons wrote:Sorry, I still confuse. :( update node_states[N_NORMAL_MEMORY] to node_states[N_MEMORY] or node_states[N_NORMAL_MEMOR] present 0...ZONE_MOVABLE? node_states is what? node_states[N_NORMAL_MEMOR] or node_states[N_MEMORY]?Are you asking what node_states[] is ? node_states[] is an array of nodemask, extern nodemask_t node_states[NR_NODE_STATES]; For example, node_states[N_NORMAL_MEMOR] represents which nodes have normal memory. If N_MEMORY == N_HIGH_MEMORY == N_NORMAL_MEMORY, node_states[N_MEMORY] is node_states[N_NORMAL_MEMOR]. So it represents which nodes have 0 ... ZONE_MOVABLE.Sorry, how can nodes_state[N_NORMAL_MEMORY] represents a node have 0 ... *ZONE_MOVABLE*, the comment of enum nodes_states said that N_NORMAL_MEMORY just means the node has regular memory.
Hi Simon, Let's say it in this way.If we don't have CONFIG_HIGHMEM, N_HIGH_MEMORY == N_NORMAL_MEMORY. We don't have a separate
macro to represent highmem because we don't have highmem. This is easy to understand, right ? Now, think it just like above:If we don't have CONFIG_MOVABLE_NODE, N_MEMORY == N_HIGH_MEMORY == N_NORMAL_MEMORY. This means we don't allow a node to have only movable memory, not we don't have movable memory. A node could have normal memory and movable memory. So nodes_state[N_NORMAL_MEMORY] represents
a node have 0 ... *ZONE_MOVABLE*.I think the point is: CONFIG_MOVABLE_NODE means we allow a node to have only movable memory. So without CONFIG_MOVABLE_NODE, it doesn't mean a node cannot have movable memory. It means the node cannot have only movable memory. It can have normal memory and movable memory.
1) With CONFIG_MOVABLE_NODE:
N_NORMAL_MEMORY: nodes who have normal memory.
normal memory only
normal and highmem
normal and highmem and movablemem
normal and movablemem
N_MEMORY: nodes who has memory (any memory)
normal memory only
normal and highmem
normal and highmem and movablemem
normal and movablemem ---------------- We can have
movablemem.
highmem only -------------------------
highmem and movablemem ---------------
movablemem only ---------------------- We can have
movablemem only. ***
2) With out CONFIG_MOVABLE_NODE:
N_MEMORY == N_NORMAL_MEMORY: (Here, I omit N_HIGH_MEMORY)
normal memory only
normal and highmem
normal and highmem and movablemem
normal and movablemem ---------------- We can have
movablemem.
No movablemem only ------------------- We cannot
have movablemem only. ***
The semantics is not that clear here. So we can only try to understand it from the code where
we use N_MEMORY. :) That is my understanding of this. Thanks. :) -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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