From 74a5ed5c4f692df2ff0a2313ea71e81243525519 Mon Sep 17 00:00:00 2001 From: Thomas Tai Date: Thu, 3 Nov 2016 09:19:01 -0700 Subject: [PATCH] sparc64: Fix find_node warning if numa node cannot be found When booting up LDOM, find_node() warns that a physical address doesn't match a NUMA node. WARNING: CPU: 0 PID: 0 at arch/sparc/mm/init_64.c:835 find_node+0xf4/0x120 find_node: A physical address doesn't match a NUMA node rule. Some physical memory will be owned by node 0.Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.9.0-rc3 #4 Call Trace: [0000000000468ba0] __warn+0xc0/0xe0 [0000000000468c74] warn_slowpath_fmt+0x34/0x60 [00000000004592f4] find_node+0xf4/0x120 [0000000000dd0774] add_node_ranges+0x38/0xe4 [0000000000dd0b1c] numa_parse_mdesc+0x268/0x2e4 [0000000000dd0e9c] bootmem_init+0xb8/0x160 [0000000000dd174c] paging_init+0x808/0x8fc [0000000000dcb0d0] setup_arch+0x2c8/0x2f0 [0000000000dc68a0] start_kernel+0x48/0x424 [0000000000dcb374] start_early_boot+0x27c/0x28c [0000000000a32c08] tlb_fixup_done+0x4c/0x64 [0000000000027f08] 0x27f08 It is because linux use an internal structure node_masks[] to keep the best memory latency node only. However, LDOM mdesc can contain single latency-group with multiple memory latency nodes. If the address doesn't match the best latency node within node_masks[], it should check for an alternative via mdesc. The warning message should only be printed if the address doesn't match any node_masks[] nor within mdesc. To minimize the impact of searching mdesc every time, the last matched mask and index is stored in a variable. Signed-off-by: Thomas Tai Reviewed-by: Chris Hyser Reviewed-by: Liam Merwick Signed-off-by: David S. Miller --- arch/sparc/mm/init_64.c | 65 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 61 insertions(+), 4 deletions(-) diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index 439784b7b7ac..068eb3dcbcb5 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -802,6 +802,8 @@ struct mdesc_mblock { }; static struct mdesc_mblock *mblocks; static int num_mblocks; +static int find_numa_node_for_addr(unsigned long pa, + struct node_mem_mask *pnode_mask); static unsigned long ra_to_pa(unsigned long addr) { @@ -821,6 +823,9 @@ static unsigned long ra_to_pa(unsigned long addr) static int find_node(unsigned long addr) { + static bool search_mdesc = true; + static struct node_mem_mask last_mem_mask = { ~0UL, ~0UL }; + static int last_index; int i; addr = ra_to_pa(addr); @@ -830,10 +835,27 @@ static int find_node(unsigned long addr) if ((addr & p->mask) == p->val) return i; } - /* The following condition has been observed on LDOM guests.*/ - WARN_ONCE(1, "find_node: A physical address doesn't match a NUMA node" - " rule. Some physical memory will be owned by node 0."); - return 0; + /* The following condition has been observed on LDOM guests because + * node_masks only contains the best latency mask and value. + * LDOM guest's mdesc can contain a single latency group to + * cover multiple address range. Print warning message only if the + * address cannot be found in node_masks nor mdesc. + */ + if ((search_mdesc) && + ((addr & last_mem_mask.mask) != last_mem_mask.val)) { + /* find the available node in the mdesc */ + last_index = find_numa_node_for_addr(addr, &last_mem_mask); + numadbg("find_node: latency group for address 0x%lx is %d\n", + addr, last_index); + if ((last_index < 0) || (last_index >= num_node_masks)) { + /* WARN_ONCE() and use default group 0 */ + WARN_ONCE(1, "find_node: A physical address doesn't match a NUMA node rule. Some physical memory will be owned by node 0."); + search_mdesc = false; + last_index = 0; + } + } + + return last_index; } static u64 memblock_nid_range(u64 start, u64 end, int *nid) @@ -1160,6 +1182,41 @@ int __node_distance(int from, int to) return numa_latency[from][to]; } +static int find_numa_node_for_addr(unsigned long pa, + struct node_mem_mask *pnode_mask) +{ + struct mdesc_handle *md = mdesc_grab(); + u64 node, arc; + int i = 0; + + node = mdesc_node_by_name(md, MDESC_NODE_NULL, "latency-groups"); + if (node == MDESC_NODE_NULL) + goto out; + + mdesc_for_each_node_by_name(md, node, "group") { + mdesc_for_each_arc(arc, md, node, MDESC_ARC_TYPE_FWD) { + u64 target = mdesc_arc_target(md, arc); + struct mdesc_mlgroup *m = find_mlgroup(target); + + if (!m) + continue; + if ((pa & m->mask) == m->match) { + if (pnode_mask) { + pnode_mask->mask = m->mask; + pnode_mask->val = m->match; + } + mdesc_release(md); + return i; + } + } + i++; + } + +out: + mdesc_release(md); + return -1; +} + static int __init find_best_numa_node_for_mlgroup(struct mdesc_mlgroup *grp) { int i; -- 2.20.1