Commit 85cc5135 authored Sep 30, 2005 by Ravikiran G Thirumalai Committed by Linus Torvalds Sep 30, 2005

[PATCH] x86_64 early numa init fix



The tests Alok carried out on Petr's box confirmed that cpu_to_node[BP] is
not setup early enough by numa_init_array due to the x86_64 changes in
2.6.14-rc*, and unfortunately set wrongly by the work around code in
numa_init_array().  cpu_to_node[0] gets set with 1 early and later gets set
properly to 0 during identify_cpu() when all cpus are brought up, but
confusing the numa slab in the process.

Here is a quick fix for this.  The right fix obviously is to have
cpu_to_node[bsp] setup early for numa_init_array().  The following patch
will fix the problem now, and the code can stay on even when
cpu_to_node{BP] gets fixed early correctly.

Thanks to Petr for access to his box.

Signed off by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Alok N Kataria <alokk@calsoftinc.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent e6a045a5

arch/x86_64/mm/numa.c

+2 −3

Original line number	Original line	Diff line number	Diff line
	@@ -167,15 +167,14 @@ void __init numa_init_array(void)
	mapping. To avoid this fill in the mapping for all possible		mapping. To avoid this fill in the mapping for all possible
	CPUs, as the number of CPUs is not known yet.		CPUs, as the number of CPUs is not known yet.
	We round robin the existing nodes. */		We round robin the existing nodes. */
	rr = 0;		rr = first_node(node_online_map);
	for (i = 0; i < NR_CPUS; i++) {		for (i = 0; i < NR_CPUS; i++) {
	if (cpu_to_node[i] != NUMA_NO_NODE)		if (cpu_to_node[i] != NUMA_NO_NODE)
	continue;		continue;
			cpu_to_node[i] = rr;
	rr = next_node(rr, node_online_map);		rr = next_node(rr, node_online_map);
	if (rr == MAX_NUMNODES)		if (rr == MAX_NUMNODES)
	rr = first_node(node_online_map);		rr = first_node(node_online_map);
	cpu_to_node[i] = rr;
	rr++;
	}		}

	}		}