From: David Rientjes Adds a numa=possible= command line option to set an additional N nodes as being possible for memory hotplug. This set of possible nodes controls nr_node_ids and the sizes of several dynamically allocated node arrays. This allows memory hotplug to create new nodes for newly added memory rather than binding it to existing nodes. The first use-case for this will be node hotplug emulation which will use these possible nodes to create new nodes to test the memory hotplug callbacks and surrounding memory hotplug code. CC: Shaohui Zheng CC: Haicheng Li Signed-off-by: David Rientjes --- Documentation/x86/x86_64/boot-options.txt | 4 ++++ arch/x86/mm/numa_64.c | 18 +++++++++++++++--- 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt --- a/Documentation/x86/x86_64/boot-options.txt +++ b/Documentation/x86/x86_64/boot-options.txt @@ -174,6 +174,10 @@ NUMA If given as an integer, fills all system RAM with N fake nodes interleaved over physical nodes. + numa=possible= + Sets an additional N nodes as being possible for memory + hotplug. + ACPI acpi=off Don't enable ACPI diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c --- a/arch/x86/mm/numa_64.c +++ b/arch/x86/mm/numa_64.c @@ -33,6 +33,7 @@ s16 apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = { int numa_off __initdata; static unsigned long __initdata nodemap_addr; static unsigned long __initdata nodemap_size; +static unsigned long __initdata numa_possible_nodes; /* * Map cpu index to node index @@ -611,7 +612,7 @@ void __init initmem_init(unsigned long start_pfn, unsigned long last_pfn, #ifdef CONFIG_NUMA_EMU if (cmdline && !numa_emulation(start_pfn, last_pfn, acpi, k8)) - return; + goto out; nodes_clear(node_possible_map); nodes_clear(node_online_map); #endif @@ -619,14 +620,14 @@ void __init initmem_init(unsigned long start_pfn, unsigned long last_pfn, #ifdef CONFIG_ACPI_NUMA if (!numa_off && acpi && !acpi_scan_nodes(start_pfn << PAGE_SHIFT, last_pfn << PAGE_SHIFT)) - return; + goto out; nodes_clear(node_possible_map); nodes_clear(node_online_map); #endif #ifdef CONFIG_K8_NUMA if (!numa_off && k8 && !k8_scan_nodes()) - return; + goto out; nodes_clear(node_possible_map); nodes_clear(node_online_map); #endif @@ -646,6 +647,15 @@ void __init initmem_init(unsigned long start_pfn, unsigned long last_pfn, numa_set_node(i, 0); memblock_x86_register_active_regions(0, start_pfn, last_pfn); setup_node_bootmem(0, start_pfn << PAGE_SHIFT, last_pfn << PAGE_SHIFT); +out: __maybe_unused + for (i = 0; i < numa_possible_nodes; i++) { + int nid; + + nid = first_unset_node(node_possible_map); + if (nid == MAX_NUMNODES) + break; + node_set(nid, node_possible_map); + } } unsigned long __init numa_free_all_bootmem(void) @@ -675,6 +685,8 @@ static __init int numa_setup(char *opt) if (!strncmp(opt, "noacpi", 6)) acpi_numa = -1; #endif + if (!strncmp(opt, "possible=", 9)) + numa_possible_nodes = simple_strtoul(opt + 9, NULL, 0); return 0; } early_param("numa", numa_setup); -- Thanks & Regards, Shaohui -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/