[Pmem] Re: [PATCH] mm: make cpu-less memory node to movable node only

From: Feng Tang <feng.tang(a)intel.com> When platform has PMEM node, those node are mostly a pure memory node without any CPU attached. To avoid performance/latency sensitive kernel allocation on these nodes, make all cpu-less memory nodes be enabled as node with movable zone only. And when users want it to be normal node, appending "cpuless_node_normal" to kernel cmdline parameters can achive that. Signed-off-by: Feng Tang <feng.tang(a)intel.com> Signed-off-by: Huaisheng Ye <huaisheng.ye(a)intel.com> --- arch/x86/mm/srat.c | 5 +++++ drivers/base/node.c | 2 ++ include/linux/nodemask.h | 1 + mm/page_alloc.c | 30 ++++++++++++++++++++++++++++++ 4 files changed, 38 insertions(+) diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c index dac07e4f5834..dcb568067d79 100644 --- a/arch/x86/mm/srat.c +++ b/arch/x86/mm/srat.c @@ -60,6 +60,9 @@ acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa) node_set(node, numa_nodes_parsed); printk(KERN_INFO "SRAT: PXM %u -> APIC 0x%04x -> Node %u\n", pxm, apic_id, node); + + if (!node_state(node, N_POSSIBLE_CPU)) + node_set_state(node, N_POSSIBLE_CPU); } /* Callback for Proximity Domain -> LAPIC mapping */ @@ -101,6 +104,8 @@ acpi_numa_processor_affinity_init(struct acpi_srat_cpu_affinity *pa) node_set(node, numa_nodes_parsed); printk(KERN_INFO "SRAT: PXM %u -> APIC 0x%02x -> Node %u\n", pxm, apic_id, node); + if (!node_state(node, N_POSSIBLE_CPU)) + node_set_state(node, N_POSSIBLE_CPU); }

int __init x86_acpi_numa_init(void) diff --git a/drivers/base/node.c b/drivers/base/node.c index 619fb1e38dd2..39ee52c69609 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -990,6 +990,7 @@ static struct node_attr node_state_attr[] = { #endif [N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY), [N_CPU] = _NODE_ATTR(has_cpu, N_CPU), + [N_POSSIBLE_CPU] = _NODE_ATTR(has_possible_cpu, N_POSSIBLE_CPU), }; static struct attribute *node_state_attrs[] = { @@ -1001,6 +1002,7 @@ static struct attribute *node_state_attrs[] = { #endif &node_state_attr[N_MEMORY].attr.attr, &node_state_attr[N_CPU].attr.attr, + &node_state_attr[N_POSSIBLE_CPU].attr.attr, NULL }; diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h index 5a30ad594ccc..ad3100b06938 100644 --- a/include/linux/nodemask.h +++ b/include/linux/nodemask.h @@ -399,6 +399,7 @@ enum node_states { #endif N_MEMORY, /* The node has memory(regular, high, movable) */ N_CPU, /* The node has one or more cpus */ + N_POSSIBLE_CPU, /* possible nodes that have cpu attached, only used in early boot phase */ NR_NODE_STATES }; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8cfce927fb9b..9570ee499c12 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -294,6 +294,7 @@ static unsigned long required_kernelcore_percent __initdata; static unsigned long required_movablecore __initdata; static unsigned long required_movablecore_percent __initdata; static unsigned long zone_movable_pfn[MAX_NUMNODES] __meminitdata; +static bool enable_cpuless_memnode_normal_node __initdata; static bool mirrored_kernelcore __meminitdata; /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ @@ -7163,6 +7164,24 @@ static void __init find_zone_movable_pfns_for_nodes(void) required_movablecore = (totalpages * 100 * required_movablecore_percent) / 10000UL; + if (!required_kernelcore && !required_movablecore && + !nodes_empty(node_states[N_POSSIBLE_CPU]) && + !enable_cpuless_memnode_normal_node) { + + /* Put meory from cpu-less nodes into movable zones */ + for_each_memblock(memory, r) { + nid = memblock_get_region_node(r); + + if (node_isset(nid, node_states[N_POSSIBLE_CPU])) + continue; + + usable_startpfn = PFN_DOWN(r->base); + zone_movable_pfn[nid] = zone_movable_pfn[nid] ? + min(usable_startpfn, zone_movable_pfn[nid]) : + usable_startpfn; + } + } + /* * If movablecore= was specified, calculate what size of * kernelcore that corresponds so that memory usable for @@ -7457,8 +7476,19 @@ static int __init cmdline_parse_movablecore(char *p) &required_movablecore_percent); } +/* + * cpuless memory nodes will be enabled to movable node by default, + * add this cmdline to make it be enabled as a normal node + */ +static int __init cmdline_parse_cpuless_memnode(char *str) +{ + enable_cpuless_memnode_normal_node = true; + return 0; +} + early_param("kernelcore", cmdline_parse_kernelcore); early_param("movablecore", cmdline_parse_movablecore); +early_param("cpuless_node_normal", cmdline_parse_cpuless_memnode); #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */