From: Michael Bringmann <m...@linux.vnet.ibm.com> To: linuxppc-dev@lists.ozlabs.org To: linux-ker...@vger.kernel.org Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Michael Bringmann <m...@linux.vnet.ibm.com> Cc: John Allen <jal...@linux.vnet.ibm.com> Cc: Nathan Fontenot <nf...@linux.vnet.ibm.com> Subject: [PATCH V10 2/2] powerpc/nodes: Ensure enough nodes avail for operations
powerpc/nodes: On systems like PowerPC which allow 'hot-add' of CPU or memory resources, it may occur that the new resources are to be inserted into nodes that were not used for these resources at bootup. In the kernel, any node that is used must be defined and initialized at boot. This patch extracts the value of the 'min_common_depth' element from the "rtas" device tree property "ibm,max-associativity-domains" to use as the maximum number of nodes to setup as possibly available in the system. [The 'min_common_depth' element is calculated from memory associations found while loading all of the configured memory into the system data structures at boot.] This new setting will override the instruction, nodes_and(node_possible_map, node_possible_map, node_online_map); presently seen in the function arch/powerpc/mm/numa.c:initmem_init(). If the property is not present at boot, no operation will be performed to define or enable additional nodes. Signed-off-by: Michael Bringmann <m...@linux.vnet.ibm.com> --- Changes in V10: -- Try to use 'min_common_depth' from NUMA initialization to select domain level to use for maximum nodes. --- arch/powerpc/mm/numa.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 73427e290..841d3b6 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -896,6 +896,48 @@ static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn) NODE_DATA(nid)->node_spanned_pages = spanned_pages; } +static void __init node_associativity_setup(void) +{ + struct device_node *rtas; + + rtas = of_find_node_by_path("/rtas"); + if (rtas) { + const __be32 *prop; + u32 len, entries, numnodes, i; + + prop = of_get_property(rtas, "ibm,max-associativity-domains", &len); + if (!prop || len < sizeof(unsigned int)) + goto endit; + + entries = of_read_number(prop++, 1); + + if (len < (entries * sizeof(unsigned int))) + goto endit; + + dbg("numa: Debug: Entries = %d MCD = %d\n", entries, min_common_depth); + + if ((0 <= min_common_depth) && (min_common_depth <= (entries-1))) + entries = min_common_depth; + else + entries -= 1; + + numnodes = of_read_number(&prop[entries], 1); + + printk(KERN_INFO "numa: Nodes = %d\n", numnodes); + + for (i = 0; i < numnodes; i++) { + if (!node_possible(i)) { + setup_node_data(i, 0, 0); + node_set(i, node_possible_map); + } + } + } + +endit: + if (rtas) + of_node_put(rtas); +} + void __init initmem_init(void) { int nid, cpu; @@ -915,6 +957,8 @@ void __init initmem_init(void) */ nodes_and(node_possible_map, node_possible_map, node_online_map); + node_associativity_setup(); + for_each_online_node(nid) { unsigned long start_pfn, end_pfn;