On Fri, Sep 11, 2020 at 09:55:23PM +1000, Michael Ellerman wrote: > Srikar Dronamraju <sri...@linux.vnet.ibm.com> writes: > > Current code assumes that cpumask of cpus sharing a l2-cache mask will > > always be a superset of cpu_sibling_mask. > > > > Lets stop that assumption. cpu_l2_cache_mask is a superset of > > cpu_sibling_mask if and only if shared_caches is set. > > I'm seeing oopses with this: > > [ 0.117392][ T1] smp: Bringing up secondary CPUs ... > [ 0.156515][ T1] smp: Brought up 2 nodes, 2 CPUs > [ 0.158265][ T1] numa: Node 0 CPUs: 0 > [ 0.158520][ T1] numa: Node 1 CPUs: 1 > [ 0.167453][ T1] BUG: Unable to handle kernel data access on read at > 0x8000000041228298 > [ 0.167992][ T1] Faulting instruction address: 0xc00000000018c128 > [ 0.168817][ T1] Oops: Kernel access of bad area, sig: 11 [#1] > [ 0.168964][ T1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries > [ 0.169417][ T1] Modules linked in: > [ 0.170047][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted > 5.9.0-rc2-00095-g7430ad5aa700 #209 > [ 0.170305][ T1] NIP: c00000000018c128 LR: c00000000018c0cc CTR: > c00000000004dce0 > [ 0.170498][ T1] REGS: c00000007e343880 TRAP: 0380 Not tainted > (5.9.0-rc2-00095-g7430ad5aa700) > [ 0.170602][ T1] MSR: 8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: > 44002222 XER: 00000000 > [ 0.170985][ T1] CFAR: c00000000018c288 IRQMASK: 0 > [ 0.170985][ T1] GPR00: 0000000000000000 c00000007e343b10 > c00000000173e400 0000000000004000 > [ 0.170985][ T1] GPR04: 0000000000000000 0000000000000800 > 0000000000000800 0000000000000000 > [ 0.170985][ T1] GPR08: 0000000000000000 c00000000122c298 > c00000003fffc000 c00000007fd05ce8 > [ 0.170985][ T1] GPR12: c00000007e0119f8 c000000001930000 > 00000000ffff8ade 0000000000000000 > [ 0.170985][ T1] GPR16: c00000007e3c0640 0000000000000917 > c00000007e3c0658 0000000000000008 > [ 0.170985][ T1] GPR20: c0000000015d0bb8 00000000ffff8ade > c000000000f57400 c000000001817c28 > [ 0.170985][ T1] GPR24: c00000000176dc80 c00000007e3c0890 > c00000007e3cfe00 0000000000000000 > [ 0.170985][ T1] GPR28: c000000001772310 c00000007e011900 > c00000007e3c0800 0000000000000001 > [ 0.172750][ T1] NIP [c00000000018c128] build_sched_domains+0x808/0x14b0 > [ 0.172900][ T1] LR [c00000000018c0cc] build_sched_domains+0x7ac/0x14b0 > [ 0.173186][ T1] Call Trace: > [ 0.173484][ T1] [c00000007e343b10] [c00000000018bfe8] > build_sched_domains+0x6c8/0x14b0 (unreliable) > [ 0.173821][ T1] [c00000007e343c50] [c00000000018dcdc] > sched_init_domains+0xec/0x130 > [ 0.174037][ T1] [c00000007e343ca0] [c0000000010d59d8] > sched_init_smp+0x50/0xc4 > [ 0.174207][ T1] [c00000007e343cd0] [c0000000010b45c4] > kernel_init_freeable+0x1b4/0x378 > [ 0.174378][ T1] [c00000007e343db0] [c0000000000129fc] > kernel_init+0x24/0x158 > [ 0.174740][ T1] [c00000007e343e20] [c00000000000d9d0] > ret_from_kernel_thread+0x5c/0x6c > [ 0.175050][ T1] Instruction dump: > [ 0.175626][ T1] 554905ee 71480040 7d2907b4 4182016c 2c290000 3920006e > 913e002c 41820034 > [ 0.175841][ T1] 7c6307b4 e9300020 78631f24 7d58182a <7d2a482a> > f93e0080 7d404828 314a0001 > [ 0.178340][ T1] ---[ end trace 6876b88dd1d4b3bb ]--- > [ 0.178512][ T1] > [ 1.180458][ T1] Kernel panic - not syncing: Attempted to kill init! > exitcode=0x0000000b > > That's qemu: > > qemu-system-ppc64 -nographic -vga none -M pseries -cpu POWER8 \ > -kernel build~/vmlinux \ > -m 2G,slots=2,maxmem=4G \ > -object memory-backend-ram,size=1G,id=m0 \ > -object memory-backend-ram,size=1G,id=m1 \ > -numa node,nodeid=0,memdev=m0 \ > -numa node,nodeid=1,memdev=m1 \ > -smp 2,sockets=2,maxcpus=2 \
PowerKVM guest vCPUs does not yet have L2 and L3 cache elements I had this bug raised some time ago, probably related? https://bugs.launchpad.net/qemu/+bug/1774605 Regards, -Satheesh. > > > On mambo I get: > > [ 0.005069][ T1] smp: Bringing up secondary CPUs ... > [ 0.011656][ T1] smp: Brought up 2 nodes, 8 CPUs > [ 0.011682][ T1] numa: Node 0 CPUs: 0-3 > [ 0.011709][ T1] numa: Node 1 CPUs: 4-7 > [ 0.012015][ T1] BUG: arch topology borken > [ 0.012040][ T1] the SMT domain not a subset of the CACHE domain > [ 0.012107][ T1] BUG: Unable to handle kernel data access on read at > 0x80000001012e7398 > [ 0.012142][ T1] Faulting instruction address: 0xc0000000001aa4f0 > [ 0.012174][ T1] Oops: Kernel access of bad area, sig: 11 [#1] > [ 0.012206][ T1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV > [ 0.012236][ T1] Modules linked in: > [ 0.012264][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted > 5.9.0-rc2-00095-g7430ad5aa700 #1 > [ 0.012304][ T1] NIP: c0000000001aa4f0 LR: c0000000001aa498 CTR: > 0000000000000000 > [ 0.012341][ T1] REGS: c0000000ef583880 TRAP: 0380 Not tainted > (5.9.0-rc2-00095-g7430ad5aa700) > [ 0.012379][ T1] MSR: 9000000002009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE> > CR: 44002222 XER: 00040000 > [ 0.012439][ T1] CFAR: c0000000000101b0 IRQMASK: 0 > [ 0.012439][ T1] GPR00: 0000000000000000 c0000000ef583b10 > c0000000017fd000 0000000000004000 > [ 0.012439][ T1] GPR04: 0000000000000000 0000000000000800 > 0000000000000000 0000000000000000 > [ 0.012439][ T1] GPR08: 0000000000000000 c0000000012eb398 > c0000000ffffc000 0000000000000000 > [ 0.012439][ T1] GPR12: 0000000000000020 c0000000019f0000 > 00000000ffff8ad1 0000000000000000 > [ 0.012439][ T1] GPR16: c0000000ef068658 c0000000018d7ba8 > 0000000000000008 c000000001690bb8 > [ 0.012439][ T1] GPR20: c00000000182dc80 c0000000ef06be90 > 00000000ffff8ad1 c000000001014aa8 > [ 0.012439][ T1] GPR24: 0000000000000917 c0000000ef068e00 > 0000000000000000 c0000000ef06be00 > [ 0.012439][ T1] GPR28: 0000000000000001 c0000000ef068640 > c0000000ef4a1800 c000000001832310 > [ 0.012774][ T1] NIP [c0000000001aa4f0] build_sched_domains+0x5c0/0x14f0 > [ 0.012812][ T1] LR [c0000000001aa498] build_sched_domains+0x568/0x14f0 > [ 0.012842][ T1] Call Trace: > [ 0.012872][ T1] [c0000000ef583b10] [c0000000001aa3b4] > build_sched_domains+0x484/0x14f0 (unreliable) > [ 0.012922][ T1] [c0000000ef583c50] [c0000000001ac3d8] > sched_init_domains+0xd8/0x120 > [ 0.012966][ T1] [c0000000ef583ca0] [c0000000011962d0] > sched_init_smp+0x50/0xc4 > [ 0.013008][ T1] [c0000000ef583cd0] [c00000000117451c] > kernel_init_freeable+0x1b4/0x378 > [ 0.013051][ T1] [c0000000ef583db0] [c000000000012994] > kernel_init+0x2c/0x158 > [ 0.013092][ T1] [c0000000ef583e20] [c00000000000d9d0] > ret_from_kernel_thread+0x5c/0x6c > [ 0.013128][ T1] Instruction dump: > [ 0.013151][ T1] e93b003a 712a0040 552a05ee 418203c4 2c2a0000 3920006e > 913b002c 41820034 > [ 0.013206][ T1] 7c6307b4 e93d0020 78631f24 7d54182a <7d2a482a> > f93b0080 7d404828 314a0001 > [ 0.013267][ T1] ---[ end trace 1bf5f6f38a9fd096 ]--- > > > Did I miss a lead-up patch? > > See here for what I have applied: > https://github.com/linuxppc/linux/commits/next-test > > cheers
