From: Christoph Lameter Online nodes now may have no memory. The checks and initialization must therefore be changed to no longer use the online functions. This will correctly initialize the interleave on bootup to only target nodes with memory and will make sys_move_pages return an error when a page is to be moved to a memoryless node. Similarly we will get an error if MPOL_BIND and MPOL_INTERLEAVE is used on a memoryless node. These are somewhat new semantics. So far one could specify memoryless nodes and we would maybe do the right thing and just ignore the node (or we'd do something strange like with MPOL_INTERLEAVE). If we want to allow the specification of memoryless nodes via memory policies then we need to keep checking for online nodes. Signed-off-by: Christoph Lameter Acked-by: Nishanth Aravamudan Tested-by: Lee Schermerhorn Acked-by: Bob Picco Cc: KAMEZAWA Hiroyuki Cc: Mel Gorman Signed-off-by: Andrew Morton --- mm/mempolicy.c | 10 +++++----- mm/migrate.c | 2 +- 2 files changed, 6 insertions(+), 6 deletions(-) diff -puN mm/mempolicy.c~memoryless-nodes-update-memory-policy-and-page-migration mm/mempolicy.c --- a/mm/mempolicy.c~memoryless-nodes-update-memory-policy-and-page-migration +++ a/mm/mempolicy.c @@ -494,9 +494,9 @@ static void get_zonemask(struct mempolic *nodes = p->v.nodes; break; case MPOL_PREFERRED: - /* or use current node instead of online map? */ + /* or use current node instead of memory_map? */ if (p->v.preferred_node < 0) - *nodes = node_online_map; + *nodes = node_states[N_HIGH_MEMORY]; else node_set(p->v.preferred_node, *nodes); break; @@ -1687,7 +1687,7 @@ void __init numa_policy_init(void) * fall back to the largest node if they're all smaller. */ nodes_clear(interleave_nodes); - for_each_online_node(nid) { + for_each_node_state(nid, N_HIGH_MEMORY) { unsigned long total_pages = node_present_pages(nid); /* Preserve the largest node */ @@ -1973,7 +1973,7 @@ int show_numa_map(struct seq_file *m, vo seq_printf(m, " huge"); } else { check_pgd_range(vma, vma->vm_start, vma->vm_end, - &node_online_map, MPOL_MF_STATS, md); + &node_states[N_HIGH_MEMORY], MPOL_MF_STATS, md); } if (!md->pages) @@ -2000,7 +2000,7 @@ int show_numa_map(struct seq_file *m, vo if (md->writeback) seq_printf(m," writeback=%lu", md->writeback); - for_each_online_node(n) + for_each_node_state(n, N_HIGH_MEMORY) if (md->node[n]) seq_printf(m, " N%d=%lu", n, md->node[n]); out: diff -puN mm/migrate.c~memoryless-nodes-update-memory-policy-and-page-migration mm/migrate.c --- a/mm/migrate.c~memoryless-nodes-update-memory-policy-and-page-migration +++ a/mm/migrate.c @@ -986,7 +986,7 @@ asmlinkage long sys_move_pages(pid_t pid goto out; err = -ENODEV; - if (!node_online(node)) + if (!node_state(node, N_HIGH_MEMORY)) goto out; err = -EACCES; _