The patch titled Subject: mm: node_states: introduce N_MEMORY has been added to the -mm tree. Its filename is node_states-introduce-n_memory.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> Subject: mm: node_states: introduce N_MEMORY We have N_NORMAL_MEMORY for standing for the nodes that have normal memory with zone_type <= ZONE_NORMAL. And we have N_HIGH_MEMORY for standing for the nodes that have normal or high memory. But we don't have any word to stand for the nodes that have *any* memory. And we have N_CPU but without N_MEMORY. Current code reuse the N_HIGH_MEMORY for this purpose because any node which has memory must have high memory or normal memory currently. A) But this reusing is bad for *readability*. Because the name N_HIGH_MEMORY just stands for high or normal: A.example 1) mem_cgroup_nr_lru_pages(): for_each_node_state(nid, N_HIGH_MEMORY) The user will be confused(why this function just counts for high or normal memory node? does it counts for ZONE_MOVABLE's lru pages?) until someone else tell them N_HIGH_MEMORY is reused to stand for nodes that have any memory. A.cont) If we introduce N_MEMORY, we can reduce this confusing AND make the code more clearly: A.example 2) mm/page_cgroup.c use N_HIGH_MEMORY twice: One is in page_cgroup_init(void): for_each_node_state(nid, N_HIGH_MEMORY) { It means if the node have memory, we will allocate page_cgroup map for the node. We should use N_MEMORY instead here to gaim more clearly. The second using is in alloc_page_cgroup(): if (node_state(nid, N_HIGH_MEMORY)) addr = vzalloc_node(size, nid); It means if the node has high or normal memory that can be allocated from kernel. We should keep N_HIGH_MEMORY here, and it will be better if the "any memory" semantic of N_HIGH_MEMORY is removed. B) This reusing is out-dated if we introduce MOVABLE-dedicated node. The MOVABLE-dedicated node should not appear in node_stats[N_HIGH_MEMORY] nor node_stats[N_NORMAL_MEMORY], because MOVABLE-dedicated node has no high or normal memory. In x86_64, N_HIGH_MEMORY=N_NORMAL_MEMORY, if a MOVABLE-dedicated node is in node_stats[N_HIGH_MEMORY], it is also means it is in node_stats[N_NORMAL_MEMORY], it causes SLUB wrong. The slub uses for_each_node_state(nid, N_NORMAL_MEMORY) and creates kmem_cache_node for MOVABLE-dedicated node and cause problem. In one word, we need a N_MEMORY. We just intrude it as an alias to N_HIGH_MEMORY and fix all im-proper usages of N_HIGH_MEMORY in late patches. Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> Acked-by: Christoph Lameter <cl@xxxxxxxxx> Acked-by: Hillf Danton <dhillf@xxxxxxxxx> Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx> Cc: Lin Feng <linfeng@xxxxxxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/nodemask.h | 1 + 1 file changed, 1 insertion(+) diff -puN include/linux/nodemask.h~node_states-introduce-n_memory include/linux/nodemask.h --- a/include/linux/nodemask.h~node_states-introduce-n_memory +++ a/include/linux/nodemask.h @@ -380,6 +380,7 @@ enum node_states { #else N_HIGH_MEMORY = N_NORMAL_MEMORY, #endif + N_MEMORY = N_HIGH_MEMORY, N_CPU, /* The node has one or more cpus */ NR_NODE_STATES }; _ Patches currently in -mm which might be from laijs@xxxxxxxxxxxxxx are linux-next.patch memory_hotplug-fix-possible-incorrect-node_states.patch slub-hotplug-ignore-unrelated-nodes-hot-adding-and-hot-removing.patch drivers-base-nodec-cleanup-node_state_attr.patch mm-memory-hotplug-dynamic-configure-movable-memory-and-portion-memory.patch mm-memory-hotplug-dynamic-configure-movable-memory-and-portion-memory-fix.patch memory_hotplug-handle-empty-zone-when-online_movable-online_kernel.patch memory_hotplug-ensure-every-online-node-has-normal-memory.patch node_states-introduce-n_memory.patch cpuset-use-n_memory-instead-n_high_memory.patch procfs-use-n_memory-instead-n_high_memory.patch memcontrol-use-n_memory-instead-n_high_memory.patch oom-use-n_memory-instead-n_high_memory.patch mmmigrate-use-n_memory-instead-n_high_memory.patch mempolicy-use-n_memory-instead-n_high_memory.patch hugetlb-use-n_memory-instead-n_high_memory.patch vmstat-use-n_memory-instead-n_high_memory.patch kthread-use-n_memory-instead-n_high_memory.patch init-use-n_memory-instead-n_high_memory.patch vmscan-use-n_memory-instead-n_high_memory.patch page_alloc-use-n_memory-instead-n_high_memory-change-the-node_states-initialization.patch hotplug-update-nodemasks-management.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html