From: Srikar Dronamraju srikar@linux.vnet.ibm.com
[ Upstream commit 6980d13f0dd189846887bbbfa43793d9a41768d3 ]
Geethika reported a trace when doing a dlpar CPU add.
------------[ cut here ]------------ WARNING: CPU: 152 PID: 1134 at kernel/sched/topology.c:2057 CPU: 152 PID: 1134 Comm: kworker/152:1 Not tainted 5.12.0-rc5-master #5 Workqueue: events cpuset_hotplug_workfn NIP: c0000000001cfc14 LR: c0000000001cfc10 CTR: c0000000007e3420 REGS: c0000034a08eb260 TRAP: 0700 Not tainted (5.12.0-rc5-master+) MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 28828422 XER: 00000020 CFAR: c0000000001fd888 IRQMASK: 0 #012GPR00: c0000000001cfc10 c0000034a08eb500 c000000001f35400 0000000000000027 #012GPR04: c0000035abaa8010 c0000035abb30a00 0000000000000027 c0000035abaa8018 #012GPR08: 0000000000000023 c0000035abaaef48 00000035aa540000 c0000035a49dffe8 #012GPR12: 0000000028828424 c0000035bf1a1c80 0000000000000497 0000000000000004 #012GPR16: c00000000347a258 0000000000000140 c00000000203d468 c000000001a1a490 #012GPR20: c000000001f9c160 c0000034adf70920 c0000034aec9fd20 0000000100087bd3 #012GPR24: 0000000100087bd3 c0000035b3de09f8 0000000000000030 c0000035b3de09f8 #012GPR28: 0000000000000028 c00000000347a280 c0000034aefe0b00 c0000000010a2a68 NIP [c0000000001cfc14] build_sched_domains+0x6a4/0x1500 LR [c0000000001cfc10] build_sched_domains+0x6a0/0x1500 Call Trace: [c0000034a08eb500] [c0000000001cfc10] build_sched_domains+0x6a0/0x1500 (unreliable) [c0000034a08eb640] [c0000000001d1e6c] partition_sched_domains_locked+0x3ec/0x530 [c0000034a08eb6e0] [c0000000002936d4] rebuild_sched_domains_locked+0x524/0xbf0 [c0000034a08eb7e0] [c000000000296bb0] rebuild_sched_domains+0x40/0x70 [c0000034a08eb810] [c000000000296e74] cpuset_hotplug_workfn+0x294/0xe20 [c0000034a08ebc30] [c000000000178dd0] process_one_work+0x300/0x670 [c0000034a08ebd10] [c0000000001791b8] worker_thread+0x78/0x520 [c0000034a08ebda0] [c000000000185090] kthread+0x1a0/0x1b0 [c0000034a08ebe10] [c00000000000ccec] ret_from_kernel_thread+0x5c/0x70 Instruction dump: 7d2903a6 4e800421 e8410018 7f67db78 7fe6fb78 7f45d378 7f84e378 7c681b78 3c62ff1a 3863c6f8 4802dc35 60000000 <0fe00000> 3920fff4 f9210070 e86100a0 ---[ end trace 532d9066d3d4d7ec ]---
Some of the per-CPU masks use cpu_cpu_mask as a filter to limit the search for related CPUs. On a dlpar add of a CPU, update cpu_cpu_mask before updating the per-CPU masks. This will ensure the cpu_cpu_mask is updated correctly before its used in setting the masks. Setting the numa_node will ensure that when cpu_cpu_mask() gets called, the correct node number is used. This code movement helped fix the above call trace.
Reported-by: Geetika Moolchandani Geetika.Moolchandani1@ibm.com Signed-off-by: Srikar Dronamraju srikar@linux.vnet.ibm.com Reviewed-by: Nathan Lynch nathanl@linux.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20210401154200.150077-1-srikar@linux.vnet.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kernel/smp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 7d6cf75a7fd8..85a1a2a9d8ed 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1417,6 +1417,9 @@ void start_secondary(void *unused)
vdso_getcpu_init(); #endif + set_numa_node(numa_cpu_lookup_table[cpu]); + set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu])); + /* Update topology CPU masks */ add_cpu_to_masks(cpu);
@@ -1435,9 +1438,6 @@ void start_secondary(void *unused) shared_caches = true; }
- set_numa_node(numa_cpu_lookup_table[cpu]); - set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu])); - smp_wmb(); notify_cpu_starting(cpu); set_cpu_online(cpu, true);