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authorSteve Wahl <steve.wahl@hpe.com>2023-08-07 09:17:30 -0500
committerDave Hansen <dave.hansen@linux.intel.com>2023-09-11 10:06:22 -0700
commit5290e88ba2c742ca77c5f5b690e5af549cfd8591 (patch)
tree530bb4a25ca320cc49e573a52a77ee4c9ba2fb5f
parent0bb80ecc33a8fb5a682236443c1e740d5c917d1d (diff)
downloadlinux-5290e88ba2c742ca77c5f5b690e5af549cfd8591.tar.gz
x86/platform/uv: Use alternate source for socket to node data
The UV code attempts to build a set of tables to allow it to do bidirectional socket<=>node lookups. But when nr_cpus is set to a smaller number than actually present, the cpu_to_node() mapping information for unused CPUs is not available to build_socket_tables(). This results in skipping some nodes or sockets when creating the tables and leaving some -1's for later code to trip. over, causing oopses. The problem is that the socket<=>node lookups are created by doing a loop over all CPUs, then looking up the CPU's APICID and socket. But if a CPU is not present, there is no way to start this lookup. Instead of looping over all CPUs, take CPUs out of the equation entirely. Loop over all APICIDs which are mapped to a valid NUMA node. Then just extract the socket-id from the APICID. This avoid tripping over disabled CPUs. Fixes: 8a50c5851927 ("x86/platform/uv: UV support for sub-NUMA clustering") Signed-off-by: Steve Wahl <steve.wahl@hpe.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20230807141730.1117278-1-steve.wahl%40hpe.com
-rw-r--r--arch/x86/kernel/apic/x2apic_uv_x.c11
1 files changed, 5 insertions, 6 deletions
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index d9f5d7492f8371..205cee5676298f 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -1533,7 +1533,7 @@ static void __init build_socket_tables(void)
{
struct uv_gam_range_entry *gre = uv_gre_table;
int nums, numn, nump;
- int cpu, i, lnid;
+ int i, lnid, apicid;
int minsock = _min_socket;
int maxsock = _max_socket;
int minpnode = _min_pnode;
@@ -1584,15 +1584,14 @@ static void __init build_socket_tables(void)
/* Set socket -> node values: */
lnid = NUMA_NO_NODE;
- for_each_possible_cpu(cpu) {
- int nid = cpu_to_node(cpu);
- int apicid, sockid;
+ for (apicid = 0; apicid < ARRAY_SIZE(__apicid_to_node); apicid++) {
+ int nid = __apicid_to_node[apicid];
+ int sockid;
- if (lnid == nid)
+ if ((nid == NUMA_NO_NODE) || (lnid == nid))
continue;
lnid = nid;
- apicid = per_cpu(x86_cpu_to_apicid, cpu);
sockid = apicid >> uv_cpuid.socketid_shift;
if (_socket_to_node[sockid - minsock] == SOCK_EMPTY)