On Mon, Dec 10, 2018 at 8:37 PM Michal Hocko wrote: > [...] > > In other words. Does the following work? I am sorry to wildguess this > way but I am not able to recreate your setups to play with this myself. > > diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c > index 1308f5408bf7..d51643e10d00 100644 > --- a/arch/x86/mm/numa.c > +++ b/arch/x86/mm/numa.c > @@ -216,8 +216,6 @@ static void __init alloc_node_data(int nid) > > node_data[nid] = nd; > memset(NODE_DATA(nid), 0, sizeof(pg_data_t)); > - > - node_set_online(nid); > } > > /** > @@ -527,6 +525,19 @@ static void __init numa_clear_kernel_node_hotplug(void) > } > } > > +static void __init init_memory_less_node(int nid) > +{ > + unsigned long zones_size[MAX_NR_ZONES] = {0}; > + unsigned long zholes_size[MAX_NR_ZONES] = {0}; > + > + free_area_init_node(nid, zones_size, 0, zholes_size); > + > + /* > + * All zonelists will be built later in start_kernel() after per cpu > + * areas are initialized. > + */ > +} > + > static int __init numa_register_memblks(struct numa_meminfo *mi) > { > unsigned long uninitialized_var(pfn_align); > @@ -570,7 +581,7 @@ static int __init numa_register_memblks(struct numa_meminfo *mi) > return -EINVAL; > > /* Finally register nodes. */ > - for_each_node_mask(nid, node_possible_map) { > + for_each_node(nid) { > u64 start = PFN_PHYS(max_pfn); > u64 end = 0; > > @@ -592,6 +603,10 @@ static int __init numa_register_memblks(struct numa_meminfo *mi) > continue; > > alloc_node_data(nid); > + if (!end) Here comes the bug, since !end can not reach here. > + init_memory_less_node(nid); > + else > + node_set_online(nid); > } > > /* Dump memblock with node info and return. */ > @@ -721,21 +736,6 @@ void __init x86_numa_init(void) > numa_init(dummy_numa_init); > } > > -static void __init init_memory_less_node(int nid) > -{ > - unsigned long zones_size[MAX_NR_ZONES] = {0}; > - unsigned long zholes_size[MAX_NR_ZONES] = {0}; > - > - /* Allocate and initialize node data. Memory-less node is now online.*/ > - alloc_node_data(nid); > - free_area_init_node(nid, zones_size, 0, zholes_size); > - > - /* > - * All zonelists will be built later in start_kernel() after per cpu > - * areas are initialized. > - */ > -} > - > /* > * Setup early cpu_to_node. > * > @@ -763,9 +763,6 @@ void __init init_cpu_to_node(void) > if (node == NUMA_NO_NODE) > continue; > > - if (!node_online(node)) > - init_memory_less_node(node); > - > numa_set_node(cpu, node); > } > } After passing extra param for earlyprintk, finally I got the following. Please get it from attachment. BTW, based on your patch, I tried the following, it works. --- arch/x86/mm/numa.c | 42 +++++++++++++++++++----------------------- 1 file changed, 19 insertions(+), 23 deletions(-) diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c index 1308f54..4874248 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -216,7 +216,6 @@ static void __init alloc_node_data(int nid) node_data[nid] = nd; memset(NODE_DATA(nid), 0, sizeof(pg_data_t)); - node_set_online(nid); } @@ -527,6 +526,21 @@ static void __init numa_clear_kernel_node_hotplug(void) } } +static void __init init_memory_less_node(int nid) +{ + unsigned long zones_size[MAX_NR_ZONES] = {0}; + unsigned long zholes_size[MAX_NR_ZONES] = {0}; + + alloc_node_data(nid); + free_area_init_node(nid, zones_size, 0, zholes_size); + node_set_online(nid); + + /* + * All zonelists will be built later in start_kernel() after per cpu + * areas are initialized. + */ +} + static int __init numa_register_memblks(struct numa_meminfo *mi) { unsigned long uninitialized_var(pfn_align); @@ -570,7 +584,7 @@ static int __init numa_register_memblks(struct numa_meminfo *mi) return -EINVAL; /* Finally register nodes. */ - for_each_node_mask(nid, node_possible_map) { + for_each_node(nid) { u64 start = PFN_PHYS(max_pfn); u64 end = 0; @@ -581,15 +595,15 @@ static int __init numa_register_memblks(struct numa_meminfo *mi) end = max(mi->blk[i].end, end); } - if (start >= end) - continue; /* * Don't confuse VM with a node that doesn't have the * minimum amount of memory: */ - if (end && (end - start) < NODE_MIN_SIZE) + if ( start >= end || (end && (end - start) < NODE_MIN_SIZE)) { + init_memory_less_node(nid); continue; + } alloc_node_data(nid); } @@ -721,21 +735,6 @@ void __init x86_numa_init(void) numa_init(dummy_numa_init); } -static void __init init_memory_less_node(int nid) -{ - unsigned long zones_size[MAX_NR_ZONES] = {0}; - unsigned long zholes_size[MAX_NR_ZONES] = {0}; - - /* Allocate and initialize node data. Memory-less node is now online.*/ - alloc_node_data(nid); - free_area_init_node(nid, zones_size, 0, zholes_size); - - /* - * All zonelists will be built later in start_kernel() after per cpu - * areas are initialized. - */ -} - /* * Setup early cpu_to_node. * @@ -763,9 +762,6 @@ void __init init_cpu_to_node(void) if (node == NUMA_NO_NODE) continue; - if (!node_online(node)) - init_memory_less_node(node); - numa_set_node(cpu, node); } } -- 1.8.3.1 > -- > Michal Hocko > SUSE Labs