From 9a245d0e1f006bc7ccf0285d0d520ed304d00c4a Mon Sep 17 00:00:00 2001 From: Srikar Dronamraju Date: Thu, 26 Aug 2021 15:35:20 +0530 Subject: [PATCH] powerpc/numa: Update cpu_cpu_map on CPU online/offline cpu_cpu_map holds all the CPUs in the DIE. However in PowerPC, when onlining/offlining of CPUs, this mask doesn't get updated. This mask is however updated when CPUs are added/removed. So when both operations like online/offline of CPUs and adding/removing of CPUs are done simultaneously, then cpumaps end up broken. WARNING: CPU: 13 PID: 1142 at kernel/sched/topology.c:898 build_sched_domains+0xd48/0x1720 Modules linked in: rpadlpar_io rpaphp mptcp_diag xsk_diag tcp_diag udp_diag raw_diag inet_diag unix_diag af_packet_diag netlink_diag bonding tls nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set rfkill nf_tables nfnetlink pseries_rng xts vmx_crypto uio_pdrv_genirq uio binfmt_misc ip_tables xfs libcrc32c dm_service_time sd_mod t10_pi sg ibmvfc scsi_transport_fc ibmveth dm_multipath dm_mirror dm_region_hash dm_log dm_mod fuse CPU: 13 PID: 1142 Comm: kworker/13:2 Not tainted 5.13.0-rc6+ #28 Workqueue: events cpuset_hotplug_workfn NIP: c0000000001caac8 LR: c0000000001caac4 CTR: 00000000007088ec REGS: c00000005596f220 TRAP: 0700 Not tainted (5.13.0-rc6+) MSR: 8000000000029033 CR: 48828222 XER: 00000009 CFAR: c0000000001ea698 IRQMASK: 0 GPR00: c0000000001caac4 c00000005596f4c0 c000000001c4a400 0000000000000036 GPR04: 00000000fffdffff c00000005596f1d0 0000000000000027 c0000018cfd07f90 GPR08: 0000000000000023 0000000000000001 0000000000000027 c0000018fe68ffe8 GPR12: 0000000000008000 c00000001e9d1880 c00000013a047200 0000000000000800 GPR16: c000000001d3c7d0 0000000000000240 0000000000000048 c000000010aacd18 GPR20: 0000000000000001 c000000010aacc18 c00000013a047c00 c000000139ec2400 GPR24: 0000000000000280 c000000139ec2520 c000000136c1b400 c000000001c93060 GPR28: c00000013a047c20 c000000001d3c6c0 c000000001c978a0 000000000000000d NIP [c0000000001caac8] build_sched_domains+0xd48/0x1720 LR [c0000000001caac4] build_sched_domains+0xd44/0x1720 Call Trace: [c00000005596f4c0] [c0000000001caac4] build_sched_domains+0xd44/0x1720 (unreliable) [c00000005596f670] [c0000000001cc5ec] partition_sched_domains_locked+0x3ac/0x4b0 [c00000005596f710] [c0000000002804e4] rebuild_sched_domains_locked+0x404/0x9e0 [c00000005596f810] [c000000000283e60] rebuild_sched_domains+0x40/0x70 [c00000005596f840] [c000000000284124] cpuset_hotplug_workfn+0x294/0xf10 [c00000005596fc60] [c000000000175040] process_one_work+0x290/0x590 [c00000005596fd00] [c0000000001753c8] worker_thread+0x88/0x620 [c00000005596fda0] [c000000000181704] kthread+0x194/0x1a0 [c00000005596fe10] [c00000000000ccec] ret_from_kernel_thread+0x5c/0x70 Instruction dump: 485af049 60000000 2fa30800 409e0028 80fe0000 e89a00f8 e86100e8 38da0120 7f88e378 7ce53b78 4801fb91 60000000 <0fe00000> 39000000 38e00000 38c00000 Fix this by updating cpu_cpu_map aka cpumask_of_node() on every CPU online/offline. Signed-off-by: Srikar Dronamraju Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210826100521.412639-5-srikar@linux.vnet.ibm.com --- arch/powerpc/include/asm/topology.h | 13 +++++++++++++ arch/powerpc/kernel/smp.c | 3 +++ arch/powerpc/mm/numa.c | 7 ++----- 3 files changed, 18 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h index a4712ec..36fcafb 100644 --- a/arch/powerpc/include/asm/topology.h +++ b/arch/powerpc/include/asm/topology.h @@ -66,6 +66,11 @@ static inline int early_cpu_to_node(int cpu) int of_drconf_to_nid_single(struct drmem_lmb *lmb); void update_numa_distance(struct device_node *node); +extern void map_cpu_to_node(int cpu, int node); +#ifdef CONFIG_HOTPLUG_CPU +extern void unmap_cpu_from_node(unsigned long cpu); +#endif /* CONFIG_HOTPLUG_CPU */ + #else static inline int early_cpu_to_node(int cpu) { return 0; } @@ -95,6 +100,14 @@ static inline int of_drconf_to_nid_single(struct drmem_lmb *lmb) } static inline void update_numa_distance(struct device_node *node) {} + +#ifdef CONFIG_SMP +static inline void map_cpu_to_node(int cpu, int node) {} +#ifdef CONFIG_HOTPLUG_CPU +static inline void unmap_cpu_from_node(unsigned long cpu) {} +#endif /* CONFIG_HOTPLUG_CPU */ +#endif /* CONFIG_SMP */ + #endif /* CONFIG_NUMA */ #if defined(CONFIG_NUMA) && defined(CONFIG_PPC_SPLPAR) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 548aa58..9cc7d3d 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1442,6 +1442,8 @@ static void remove_cpu_from_masks(int cpu) struct cpumask *(*mask_fn)(int) = cpu_sibling_mask; int i; + unmap_cpu_from_node(cpu); + if (shared_caches) mask_fn = cpu_l2_cache_mask; @@ -1526,6 +1528,7 @@ static void add_cpu_to_masks(int cpu) * This CPU will not be in the online mask yet so we need to manually * add it to it's own thread sibling mask. */ + map_cpu_to_node(cpu, cpu_to_node(cpu)); cpumask_set_cpu(cpu, cpu_sibling_mask(cpu)); cpumask_set_cpu(cpu, cpu_core_mask(cpu)); diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 52bc63e..6f14c8f 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -142,7 +142,7 @@ static void reset_numa_cpu_lookup_table(void) numa_cpu_lookup_table[cpu] = -1; } -static void map_cpu_to_node(int cpu, int node) +void map_cpu_to_node(int cpu, int node) { update_numa_cpu_lookup_table(cpu, node); @@ -153,7 +153,7 @@ static void map_cpu_to_node(int cpu, int node) } #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR) -static void unmap_cpu_from_node(unsigned long cpu) +void unmap_cpu_from_node(unsigned long cpu) { int node = numa_cpu_lookup_table[cpu]; @@ -800,9 +800,6 @@ static int ppc_numa_cpu_prepare(unsigned int cpu) static int ppc_numa_cpu_dead(unsigned int cpu) { -#ifdef CONFIG_HOTPLUG_CPU - unmap_cpu_from_node(cpu); -#endif return 0; } -- 2.7.4