<snaps fingers> it happened again.
I tried the following combination, segfaulted with exit code 4 after zeroeth step, tried to repeat and it stalled.
env OMP_NUM_THREADS=4 mpirun -np 32 ../src/lmp_knl -in lmp.in -var NSTEPS 10 -sf omp
One difference I see is that I’ve been sourcing the following copied from the sniper setup I use. This shouldn’t be related, right?
source /soft/compilers/intel/compilers_and_libraries/linux/bin/compilervars.sh intel64
source /soft/compilers/intel/compilers_and_libraries/linux/mpi/bin64/mpivars.sh
chris
> On Mar 18, 2016, at 5:24 PM, Allen, Benjamin S. <bsallen(a)alcf.anl.gov> wrote:
>
> Ok, not the best solution, but I just rebooted the node into the 4.5.0 mainline kernel. For anyone that's run their code or benchmarks already, I'd suggest re-running your tests again to see if this breaks/slows/improves anything. 4.5.0 is also quite a bit newer kernel than we'll be running on Theta. Assuming Theta compute runs a SLES 12 derived kernel, it'll be 3.12 based.
>
> I've also enabled kdump to write out a vmcore to /soft/var/crash/`hostname` on kernel panic so we'll actually have something to work with if this happens again.
>
> Chris,
>
> I've now ran the following a few times successfully:
>
> source /soft/compilers/intel/mkl/bin/mklvars.sh intel64
> source /soft/compilers/intel/impi_latest/bin64/mpivars.sh
>
> env OMP_NUM_THREADS=4 mpirun -np 64 ../src/lmp_knl -in lmp.in -var NSTEPS 1000
>
> Please free to continue with your testing.
>
> Ben
>
>> On Mar 18, 2016, at 3:51 PM, Allen, Benjamin S. <bsallen(a)alcf.anl.gov> wrote:
>>
>> Yea you hit the same issue again. I kept a console open this go around. It appears we're hitting a null pointer deref in the kernel's scheduler:
>>
>> BUG: unable to handle kernel NULL pointer dereference at 00000000000001fa
>> [ 1275.736095] IP: [<ffffffff810c2b74>] task_tick_fair+0x5a4/0x670
>> [ 1275.742977] PGD 2f26429067 PUD 2f23ca6067 PMD 0
>> [ 1275.748524] Oops: 0002 [#1] SMP
>> [ 1275.752409] Modules linked in: nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache rdma_ucm(OE) ib_ucm(OE) rdma_cm(OE) iw_cm(OE) ib_ipoib(OE) ib_cm(OE) ib_uverbs(OE) ib_umad(OE) mlx5_ib(OE) mlx5_core(OE) mlx4_en(OE) vxlan ip6_udp_tunnel udp_tunnel mlx4_ib(OE) ib_sa(OE) mlx4_core(OE) iTCO_wdt iTCO_vendor_support intel_powerclamp coretemp intel_rapl kvm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel mgag200 aesni_intel syscopyarea lrw sysfillrect gf128mul sysimgblt glue_helper ablk_helper ttm cryptd pcspkr drm_kms_helper ib_mad(OE) ib_core(OE) drm mei_me sg lpc_ich i2c_i801 ib_addr(OE) mfd_core mei mlx_compat(OE) shpchp wmi acpi_power_meter acpi_pad binfmt_misc nfsd knem(OE) auth_rpcgss nfs_acl lockd grace sunrpc ip_tables ext4 jbd2 mbcache ipmi_si ipmi_devintf ipmi_msghandler igb i2c_algo_bit dca ptp pps_core i2c_core ahci libahci libata sd_mod crc_t10dif crct10dif_common
>> [ 1275.848733] CPU: 83 PID: 10669 Comm: lmp_knl Tainted: G OE ------------ 3.10.0-327.10.1.el7.x86_64 #1
>> [ 1275.860566] Hardware name: Intel Corporation S7200AP/S7200AP, BIOS S72C610.86B.01.01.0041.112720151659 11/27/2015
>> [ 1275.872302] task: ffff882cb03f7300 ti: ffff882f13c54000 task.ti: ffff882f13c54000
>> [ 1275.880867] RIP: 0010:[<ffffffff810c2b74>] [<ffffffff810c2b74>] task_tick_fair+0x5a4/0x670
>> [ 1275.890516] RSP: 0000:ffff882f7da63dd8 EFLAGS: 00010002
>> [ 1275.896611] RAX: 000038b712dcb4a2 RBX: 000000000000017a RCX: 0000000000000001
>> [ 1275.904786] RDX: 000000000000bc00 RSI: 00000000000039f5 RDI: 0000000000000000
>> [ 1275.912967] RBP: ffff882f7da63e28 R08: 0000000000000000 R09: 0000000000000000
>> [ 1275.921143] R10: 0000000000000004 R11: 0000000000000005 R12: 0000000000000000
>> [ 1275.929325] R13: ffff882f7da74800 R14: ffff882f7da74780 R15: 0000000000000000
>> [ 1275.937506] FS: 00007f83194aab80(0000) GS:ffff882f7da60000(0000) knlGS:0000000000000000
>> [ 1275.946776] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [ 1275.953379] CR2: 00000000000001fa CR3: 0000002f26fe4000 CR4: 00000000001407e0
>> [ 1275.968365] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> [ 1275.983284] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
>> [ 1275.998089] Stack:
>> [ 1276.007173] ffff882f7da63de8 ffffffff8101cd69 ffff882f7da63e08 ffffffff810bb655
>> [ 1276.022943] ffff882cb03f7300 ffff882f7da74780 0000000000000053 0000000000000053
>> [ 1276.038667] 0000000000014780 ffff882cb03f7300 ffff882f7da63e60 ffffffff810b75e8
>> [ 1276.054382] Call Trace:
>> [ 1276.063947] <IRQ>
>> [ 1276.066275] [<ffffffff8101cd69>] ? sched_clock+0x9/0x10
>> [ 1276.085997] [<ffffffff810bb655>] ? sched_clock_cpu+0x85/0xc0
>> [ 1276.099140] [<ffffffff810b75e8>] scheduler_tick+0xc8/0x150
>> [ 1276.111712] [<ffffffff810e06e0>] ? tick_sched_handle.isra.14+0x60/0x60
>> [ 1276.123778] [<ffffffff8108e8c6>] update_process_times+0x66/0x80
>> [ 1276.135116] [<ffffffff810e06a5>] tick_sched_handle.isra.14+0x25/0x60
>> [ 1276.146903] [<ffffffff810e0721>] tick_sched_timer+0x41/0x70
>> [ 1276.157799] [<ffffffff810a9d12>] __hrtimer_run_queues+0xd2/0x260
>> [ 1276.169156] [<ffffffff810aa2b0>] hrtimer_interrupt+0xb0/0x1e0
>> [ 1276.180177] [<ffffffff8164735c>] ? call_softirq+0x1c/0x30
>> [ 1276.190766] [<ffffffff81049537>] local_apic_timer_interrupt+0x37/0x60
>> [ 1276.202484] [<ffffffff81647fcf>] smp_apic_timer_interrupt+0x3f/0x60
>> [ 1276.213984] [<ffffffff8164669d>] apic_timer_interrupt+0x6d/0x80
>> [ 1276.225074] <EOI>
>> [ 1276.227325] [<ffffffff81645a49>] ? system_call_fastpath+0x16/0x1b
>> [ 1276.243048] Code: 9e 1c 0a 00 00 41 8b 86 18 0a 00 00 e9 08 fe ff ff 49 8b 84 24 e8 00 00 00 e9 4a fd ff ff 48 c7 46 68 00 00 00 00 e9 69 fc ff ff <c7> 83 80 00 00 00 00 00 00 00 c7 83 84 00 00 00 00 00 00 00 31
>> [ 1276.275761] RIP [<ffffffff810c2b74>] task_tick_fair+0x5a4/0x670
>> [ 1276.286963] RSP <ffff882f7da63dd8>
>> [ 1276.295181] CR2: 00000000000001fa
>>
>> The kernel then goes on to send NMI to the rest of the CPUs:
>>
>> [ 1344.258750] sending NMI to all CPUs:
>>
>> The NMIs were what I was seeing last go around. This is going to be a painful to fix.
>>
>> Ben
>>
>>
>>> On Mar 18, 2016, at 3:48 PM, Christopher Knight <knightc(a)anl.gov> wrote:
>>>
>>> I think I broke it again…
>>>
>>> This time I made my way up to 32 MPI ranks and 4 threads per rank. This run segfaulted at very end after main compute phase finished with an exit code of 4. I tried turning on core files with ‘ulimit -c unlimited’ and rerunning to reproduce and see what happened. It stalled right away while reading the input file.
>>>
>>> chris
>>>
>>>
>>>
>>>
>>> On Mar 18, 2016, at 3:29 PM, Allen, Benjamin S. <bsallen(a)alcf.anl.gov> wrote:
>>>
>>> Odd. The machine is back up, feel free to continue your testing.
>>>
>>> Ben
>>>
>>>> On Mar 18, 2016, at 3:26 PM, Christopher Knight <knightc(a)anl.gov> wrote:
>>>>
>>>> Hi Ben,
>>>>
>>>> If it did, it’s definitely not expected behavior for this small test. Memory footprint should have been relatively small, definitely less than several GBs.
>>>>
>>>>
>>>> The run just before that was fine and LAMMPS reported an (under) estimate of 18 MBs per MPI rank. The initial series of runs was from 1 to 64 MPI ranks like in the following.
>>>>
>>>> [knightc@knl00 rhodo]$ mpirun -np 64 ../src/lmp_knl -in lmp.in -var NSTEPS 10
>>>> …
>>>> Loop time of 0.480942 on 64 procs (64 MPI x 1 OpenMP) for 10 steps with 32000 atoms
>>>>
>>>>
>>>>
>>>> When I subsequently tried increasing number of OpenMP threads to 2 for that last run, the code made it past step 0 and then stalled.
>>>>
>>>> [knightc@knl00 rhodo]$ env OMP_NUM_THREADS=2 mpirun -np 64 ../src/lmp_knl -in lmp.in -var NSTEPS 10
>>>> ...
>>>> Setting up run ...
>>>> Memory usage per processor = 18.0914 Mbytes
>>>> ---------------- Step 0 ----- CPU = 0.0000 (sec) ----------------
>>>> TotEng = -25691.3377 KinEng = 21444.8313 Temp = 299.0397
>>>> PotEng = -47136.1690 E_bond = 2537.9940 E_angle = 10921.3742
>>>> E_dihed = 5211.7865 E_impro = 213.5116 E_vdwl = -2637.3323
>>>> E_coul = 162089.4165 E_long = -225472.9195 Press = -223.9562
>>>>
>>>> … then sat here for little while doing nothing.
>>>>
>>>>
>>>> chris
>>>>
>>>>
>>>>
>>>>
>>>> On Mar 18, 2016, at 3:16 PM, Allen, Benjamin S. <bsallen(a)alcf.anl.gov> wrote:
>>>>
>>>> Chris,
>>>>
>>>> The console was printing the following panic per core it appears:
>>>>
>>>> [349243.677483] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
>>>> [349243.709061] NMI backtrace for cpu 104
>>>> [349243.717125] CPU: 104 PID: 0 Comm: swapper/104 Tainted: G W OE ------------ 3.10.0-327.10.1.el7.x86_64 #1
>>>> [349243.732898] Hardware name: Intel Corporation S7200AP/S7200AP, BIOS S72C610.86B.01.01.0041.112720151659 11/27/2015
>>>> [349243.748571] task: ffff882f337bc500 ti: ffff882f337e8000 task.ti: ffff882f337e8000
>>>> [349243.761187] RIP: 0010:[<ffffffff81058e96>] [<ffffffff81058e96>] native_safe_halt+0x6/0x10
>>>> [349243.774763] RSP: 0018:ffff882f337ebe98 EFLAGS: 00000286
>>>> [349243.784946] RAX: 00000000ffffffed RBX: ffff882f337e8000 RCX: 0100000000000000
>>>> [349243.797189] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000046
>>>> [349243.809426] RBP: ffff882f337ebe98 R08: 0000000000000000 R09: 0000000000000f9f
>>>> [349243.821694] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000068
>>>> [349243.833914] R13: ffff882f337e8000 R14: ffff882f337e8000 R15: 0000000000000000
>>>> [349243.846094] FS: 0000000000000000(0000) GS:ffff882f7dd00000(0000) knlGS:0000000000000000
>>>> [349243.859415] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>>> [349243.870100] CR2: 00007f89e6a83185 CR3: 000000000194a000 CR4: 00000000001407e0
>>>> [349243.882346] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>>>> [349243.894577] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
>>>> [349243.906788] Stack:
>>>> [349243.913242] ffff882f337ebeb8 ffffffff8101dbcf ffff882f337e8000 ffffffff81a68260
>>>> [349243.926105] ffff882f337ebec8 ffffffff8101e4d6 ffff882f337ebf20 ffffffff810d62c5
>>>> [349243.938850] ffff882f337ebfd8 ffff882f337e8000 6890e75d0dc16093 307f0504002da88b
>>>> [349243.951521] Call Trace:
>>>> [349243.958359] [<ffffffff8101dbcf>] default_idle+0x1f/0xc0
>>>> [349243.968375] [<ffffffff8101e4d6>] arch_cpu_idle+0x26/0x30
>>>> [349243.978393] [<ffffffff810d62c5>] cpu_startup_entry+0x245/0x290
>>>> [349243.988910] [<ffffffff810475fa>] start_secondary+0x1ba/0x230
>>>>
>>>> This has happened before when we only had 16GB installed. Any chance your app ran through the system's 192GB of RAM?
>>>>
>>>> Ben
>>>>
>>>>> On Mar 18, 2016, at 2:49 PM, Christopher Knight <knightc(a)anl.gov> wrote:
>>>>>
>>>>> Hi Ben,
>>>>>
>>>>> knl00 is down. I was running some quick LAMMPS tests to get a feel for things and looks like something bad happened in middle of run. Trying to ssh from another shell gives me the “No route to host” error.
>>>>>
>>>>> Should I send emails like this to intel-ada(a)jlse.anl.gov to report this type of issue?
>>>>>
>>>>> chris
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>