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Commit 74a5ed5c authored by Thomas Tai's avatar Thomas Tai Committed by David S. Miller
Browse files

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: default avatarThomas Tai <thomas.tai@oracle.com>
Reviewed-by: default avatarChris Hyser <chris.hyser@oracle.com>
Reviewed-by: default avatarLiam Merwick <liam.merwick@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 27bcd37e

arch/sparc/mm/init_64.c

+61 −4
Original line number Diff line number Diff line
@@ -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;