rcu_sched stall OR kernel panic on PowerEdge R640

[george1421]

@djgalloway In the fog settings -> fog configuration page there is a field called “log level” or something close to that. The default is 4, set it to 7 to see if we can get some of the prestartup error logs. It should not just hang.

[djgalloway]

@george1421 There is no additional output. Here is the machine’s boot.php:

#!ipxe
set fog-ip 10.8.128.2
set fog-webroot fog
set boot-url http://${fog-ip}/${fog-webroot}
kernel bzImage32 loglevel=7 initrd=init_32.xz root=/dev/ram0 rw ramdisk_size=127000 web=http://10.8.128.2/fog/ consoleblank=0 rootfstype=ext4 console=tty0 console=ttyS0,115200 acpi=off mac=e4:43:4b:7d:a9:ba ftp=10.8.128.2 storage=10.8.128.2:/opt/fog/images/dev/ storageip=10.8.128.2 osid=50 irqpoll hostname=plena001 chkdsk=0 img=plena_rhel_7.7 imgType=n imgPartitionType=all imgid=46 imgFormat=0 PIGZ_COMP=-6 fdrive=/dev/sda hostearly=1 pct=5 ignorepg=1 type=up console=tty0 console=ttyS0,115200 acpi=off
imgfetch init_32.xz
boot

[george1421]

@djgalloway said in rcu_sched stall OR kernel panic on PowerEdge R640:

console=tty0 console=ttyS0,115200

Why is this in the kernel parameters, its switching the console over to the serial port and not the display.

I would also wonder if this will be a problem in the future fdrive=/dev/sda Does the raid array present itself as a SATA attached device (/dev/sda) or something else?

[djgalloway]

@george1421 console=tty0 so I get output via VGA or the iDRAC console and console=ttyS0,115200 so I also get output via the BMC’s Serial-Over-LAN interface. I just got rid of both console= parameters and it’s still stuck with no additional output.

I was first able to install this machine using Cobbler and the root drive is /dev/sda. Even if there was a disk problem, I would still expect to see some FOG output of an attempted Capture/Deploy task.

I did just confirm that I can Deploy an OS on a different machine type just to make sure the kernels/inits were okay too.

Thank you for your help so far!

[Sebastian Roth]

@djgalloway Seems like this kernel version hangs on this particular hardware. We’d need to compile a debug enabled kernel to figure out where exactly it hangs. Though as I don’t have much time these days I’d ask you to look into compiling the kernel yourself. We have instrcutions on this. Are you willing to go down this road?

[djgalloway]

@Sebastian-Roth Sure, I can follow docs. The wiki seems to be down at the moment though

[george1421]

@Sebastian-Roth I still have my kernel dev environment setup. What do we need to enable in the kernel for debugging?

[george1421]

@djgalloway Is this system in uefi or bios (legacy) mode?

So the only difference between the kernel starting and not is the acpi=off being used?

[djgalloway]

@george1421 Yes, BIOS mode.

[george1421]

@djgalloway Just for clarity

So the only difference between the kernel starting and not is the acpi=off being used?

Is this still accurate?

[djgalloway]

@george1421 Right. So, it turns out I had the wrong serial TTY set. I changed it to console=ttyS1,115200 without acpi=off and got the following:

Linux version 4.19.64 (jenkins-agent@Tollana) (gcc version 6.3.0 20170516 (Debian 6.3.0-18+deb9u1)) #1 SMP Mon Aug 5 11:08:49 CDT 2019
Command line: loglevel=7 initrd=init.xz root=/dev/ram0 rw ramdisk_size=127000 web=http://10.8.128.2/fog/ consoleblank=0 rootfstype=ext4 console=tty0 console=ttyS1,115200 mac=e4:43:4b:7d:a9:ba ftp=10.8.128.2 storage=10.8.128.2:/opt/fog/images/dev/ storageip=10.8.128.2 osi0
KERNEL supported cpus:
  Intel GenuineIntel
  AMD AuthenticAMD
  Centaur CentaurHauls
x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers'
x86/fpu: Supporting XSAVE feature 0x002: 'SSE registers'
x86/fpu: Supporting XSAVE feature 0x004: 'AVX registers'
x86/fpu: Supporting XSAVE feature 0x008: 'MPX bounds registers'
x86/fpu: Supporting XSAVE feature 0x010: 'MPX CSR'
x86/fpu: Supporting XSAVE feature 0x020: 'AVX-512 opmask'
x86/fpu: Supporting XSAVE feature 0x040: 'AVX-512 Hi256'
x86/fpu: Supporting XSAVE feature 0x080: 'AVX-512 ZMM_Hi256'
x86/fpu: Supporting XSAVE feature 0x200: 'Protection Keys User registers'
x86/fpu: xstate_offset[2]:  576, xstate_sizes[2]:  256
x86/fpu: xstate_offset[3]:  832, xstate_sizes[3]:   64
x86/fpu: xstate_offset[4]:  896, xstate_sizes[4]:   64
x86/fpu: xstate_offset[5]:  960, xstate_sizes[5]:   64
x86/fpu: xstate_offset[6]: 1024, xstate_sizes[6]:  512
x86/fpu: xstate_offset[7]: 1536, xstate_sizes[7]: 1024
x86/fpu: xstate_offset[9]: 2560, xstate_sizes[9]:    8
x86/fpu: Enabled xstate features 0x2ff, context size is 2568 bytes, using 'compacted' format.
BIOS-provided physical RAM map:
BIOS-e820: [mem 0x0000000000000000-0x000000000008bfff] usable
BIOS-e820: [mem 0x000000000008c000-0x000000000009ffff] reserved
BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved
BIOS-e820: [mem 0x0000000000100000-0x000000005ddfefff] usable
BIOS-e820: [mem 0x000000005ddff000-0x000000006cffefff] reserved
BIOS-e820: [mem 0x000000006cfff000-0x000000006effefff] ACPI NVS
BIOS-e820: [mem 0x000000006efff000-0x000000006f7fefff] ACPI data
BIOS-e820: [mem 0x000000006f7ff000-0x000000006f7fffff] usable
BIOS-e820: [mem 0x000000006f800000-0x000000008fffffff] reserved
BIOS-e820: [mem 0x00000000fd000000-0x00000000fe7fffff] reserved
BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved
BIOS-e820: [mem 0x00000000fec80000-0x00000000fed00fff] reserved
BIOS-e820: [mem 0x00000000fed40000-0x00000000fed44fff] reserved
BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved
BIOS-e820: [mem 0x0000000100000000-0x000000183fffffff] usable
NX (Execute Disable) protection: active
SMBIOS 3.2 present.
DMI: Dell Inc. PowerEdge R640/08HT8T, BIOS 2.2.11 06/13/2019
tsc: Detected 2200.000 MHz processor
last_pfn = 0x1840000 max_arch_pfn = 0x400000000
x86/PAT: Configuration [0-7]: WB  WC  UC- UC  WB  WP  UC- WT  
x2apic: enabled by BIOS, switching to x2apic ops
last_pfn = 0x6f800 max_arch_pfn = 0x400000000
Using GB pages for direct mapping
RAMDISK: [mem 0x5ca97000-0x5dd50fff]
ACPI: Early table checksum verification disabled
ACPI: RSDP 0x00000000000FE320 000024 (v02 DELL  )
ACPI: XSDT 0x000000006F41B188 0000F4 (v01 DELL   PE_SC3   00000000      01000013)
ACPI: FACP 0x000000006F7F9000 000114 (v06 DELL   PE_SC3   00000000 DELL 00000001)
ACPI: DSDT 0x000000006F507000 2E2494 (v02 DELL   PE_SC3   00000003 DELL 00000001)
ACPI: FACS 0x000000006EA6E000 000040
ACPI: SSDT 0x000000006F7FC000 00046C (v02 INTEL  ADDRXLAT 00000001 INTL 20180508)
ACPI: WDAT 0x000000006F7FB000 000134 (v01 DELL   PE_SC3   00000001 DELL 00000001)
ACPI: SLIC 0x000000006F7FA000 000024 (v01 DELL   PE_SC3   00000001 DELL 00000001)
ACPI: HPET 0x000000006F7F8000 000038 (v01 DELL   PE_SC3   00000001 DELL 00000001)
ACPI: APIC 0x000000006F7F6000 0016DE (v04 DELL   PE_SC3   00000000 DELL 00000001)
ACPI: MCFG 0x000000006F7F5000 00003C (v01 DELL   PE_SC3   00000001 DELL 00000001)
ACPI: MIGT 0x000000006F7F4000 000040 (v01 DELL   PE_SC3   00000000 DELL 00000001)
ACPI: MSCT 0x000000006F7F3000 000090 (v01 DELL   PE_SC3   00000001 DELL 00000001)
ACPI: PCAT 0x000000006F7F2000 000088 (v02 DELL   PE_SC3   00000002 DELL 00000001)
ACPI: PCCT 0x000000006F7F1000 00006E (v01 DELL   PE_SC3   00000002 DELL 00000001)
ACPI: RASF 0x000000006F7F0000 000030 (v01 DELL   PE_SC3   00000001 DELL 00000001)
ACPI: SLIT 0x000000006F7EF000 00042C (v01 DELL   PE_SC3   00000001 DELL 00000001)
ACPI: SRAT 0x000000006F7EC000 002D30 (v03 DELL   PE_SC3   00000002 DELL 00000001)
ACPI: SVOS 0x000000006F7EB000 000032 (v01 DELL   PE_SC3   00000000 DELL 00000001)
ACPI: WSMT 0x000000006F7EA000 000028 (v01 DELL   PE_SC3   00000000 DELL 00000001)
ACPI: OEM4 0x000000006F459000 0AD1C1 (v02 INTEL  CPU  CST 00003000 INTL 20180508)
ACPI: SSDT 0x000000006F421000 037465 (v02 INTEL  SSDT  PM 00004000 INTL 20180508)
ACPI: SSDT 0x000000006F407000 000A1F (v02 DELL   PE_SC3   00000000 DELL 00000001)
ACPI: SSDT 0x000000006F41D000 00357F (v02 INTEL  SpsNm    00000002 INTL 20180508)
ACPI: SPCR 0x000000006F41C000 000050 (v02                 00000000      00000000)
ACPI: DMAR 0x000000006F7FD000 000260 (v01 DELL   PE_SC3   00000001 DELL 00000001)
ACPI: HEST 0x000000006F3F6000 00017C (v01 DELL   PE_SC3   00000002 DELL 00000001)
ACPI: BERT 0x000000006F3F5000 000030 (v01 DELL   PE_SC3   00000002 DELL 00000001)
ACPI: ERST 0x000000006F3F4000 000230 (v01 DELL   PE_SC3   00000002 DELL 00000001)
ACPI: EINJ 0x000000006F3F3000 000150 (v01 DELL   PE_SC3   00000002 DELL 00000001)
Setting APIC routing to cluster x2apic.
Zone ranges:
  DMA      [mem 0x0000000000001000-0x0000000000ffffff]
  DMA32    [mem 0x0000000001000000-0x00000000ffffffff]
  Normal   [mem 0x0000000100000000-0x000000183fffffff]
Movable zone start for each node
Early memory node ranges
  node   0: [mem 0x0000000000001000-0x000000000008bfff]
  node   0: [mem 0x0000000000100000-0x000000005ddfefff]
  node   0: [mem 0x000000006f7ff000-0x000000006f7fffff]
  node   0: [mem 0x0000000100000000-0x000000183fffffff]
Reserved but unavailable: 117 pages
Initmem setup node 0 [mem 0x0000000000001000-0x000000183fffffff]
ACPI: PM-Timer IO Port: 0x508
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 8/0x4 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 9/0x24 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 10/0x18 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 11/0x38 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 12/0x10 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 13/0x30 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 14/0x16 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 15/0x36 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 16/0x12 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 17/0x32 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 18/0x14 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 19/0x34 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 20/0x1 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 21/0x21 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 22/0x9 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 23/0x29 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 24/0x3 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 25/0x23 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 26/0x7 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 27/0x27 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 28/0x5 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 29/0x25 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 30/0x19 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 31/0x39 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 32/0x11 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 33/0x31 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 34/0x17 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 35/0x37 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 36/0x13 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 37/0x33 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 38/0x15 ignored.
APIC: NR_CPUS/possible_cpus limit of 8 reached. Processor 39/0x35 ignored.
ACPI: X2APIC_NMI (uid[0xffffffff] high level lint[0x1])
ACPI: LAPIC_NMI (acpi_id[0xff] high level lint[0x1])
IOAPIC[0]: apic_id 8, version 32, address 0xfec00000, GSI 0-23
IOAPIC[1]: apic_id 9, version 32, address 0xfec01000, GSI 24-31
IOAPIC[2]: apic_id 10, version 32, address 0xfec08000, GSI 32-39
IOAPIC[3]: apic_id 11, version 32, address 0xfec10000, GSI 40-47
IOAPIC[4]: apic_id 12, version 32, address 0xfec18000, GSI 48-55
IOAPIC[5]: apic_id 15, version 32, address 0xfec20000, GSI 72-79
IOAPIC[6]: apic_id 16, version 32, address 0xfec28000, GSI 80-87
IOAPIC[7]: apic_id 17, version 32, address 0xfec30000, GSI 88-95
IOAPIC[8]: apic_id 18, version 32, address 0xfec38000, GSI 96-103
ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl)
ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
Using ACPI (MADT) for SMP configuration information
ACPI: HPET id: 0x8086a701 base: 0xfed00000
ACPI: SPCR: console: uart,io,0x2f8,115200
smpboot: 40 Processors exceeds NR_CPUS limit of 8
smpboot: Allowing 8 CPUs, 0 hotplug CPUs
[mem 0x90000000-0xfcffffff] available for PCI devices
Booting paravirtualized kernel on bare hardware
clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 1910969940391419 ns
random: get_random_bytes called from 0xffffffff82cafa32 with crng_init=0
setup_percpu: NR_CPUS:8 nr_cpumask_bits:8 nr_cpu_ids:8 nr_node_ids:1
percpu: Embedded 41 pages/cpu s130840 r8192 d28904 u262144
Built 1 zonelists, mobility grouping on.  Total pages: 24376830
Kernel command line: loglevel=7 initrd=init.xz root=/dev/ram0 rw ramdisk_size=127000 web=http://10.8.128.2/fog/ consoleblank=0 rootfstype=ext4 console=tty0 console=ttyS1,115200 mac=e4:43:4b:7d:a9:ba ftp=10.8.128.2 storage=10.8.128.2:/opt/fog/images/dev/ storageip=10.8.120
Misrouted IRQ fixup and polling support enabled
This may significantly impact system performance
Dentry cache hash table entries: 8388608 (order: 14, 67108864 bytes)
Inode-cache hash table entries: 4194304 (order: 13, 33554432 bytes)
Memory: 97287048K/99055148K available (16392K kernel code, 992K rwdata, 4548K rodata, 1056K init, 2416K bss, 1768100K reserved, 0K cma-reserved)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=8, Nodes=1
Kernel/User page tables isolation: enabled
rcu: Hierarchical RCU implementation.
NR_IRQS: 4352, nr_irqs: 1848, preallocated irqs: 16
Console: colour VGA+ 80x25
console [tty0] enabled
console [ttyS1] enabled
ACPI: Core revision 20180810
clocksource: hpet: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 79635855245 ns
APIC: Switch to symmetric I/O mode setup
x2apic: IRQ remapping doesn't support X2APIC mode
x2apic disabled
Switched APIC routing to flat.
..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
clocksource: tsc-early: mask: 0xffffffffffffffff max_cycles: 0x1fb633008a4, max_idle_ns: 440795292230 ns
Calibrating delay loop (skipped), value calculated using timer frequency.. 4400.00 BogoMIPS (lpj=2200000)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 131072 (order: 8, 1048576 bytes)
Mountpoint-cache hash table entries: 131072 (order: 8, 1048576 bytes)
ENERGY_PERF_BIAS: Set to 'normal', was 'performance'
ENERGY_PERF_BIAS: View and update with x86_energy_perf_policy(8)
process: using mwait in idle threads
Last level iTLB entries: 4KB 64, 2MB 8, 4MB 8
Last level dTLB entries: 4KB 64, 2MB 0, 4MB 0, 1GB 4
Spectre V2 : Mitigation: Full generic retpoline
Spectre V2 : Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch
Spectre V2 : Enabling Restricted Speculation for firmware calls
Spectre V2 : mitigation: Enabling conditional Indirect Branch Prediction Barrier
Spectre V2 : User space: Mitigation: STIBP via seccomp and prctl
Speculative Store Bypass: Mitigation: Speculative Store Bypass disabled via prctl and seccomp
MDS: Mitigation: Clear CPU buffers
Freeing SMP alternatives memory: 52K
smpboot: CPU0: Intel(R) Xeon(R) Silver 4114 CPU @ 2.20GHz (family: 0x6, model: 0x55, stepping: 0x4)
Performance Events: PEBS fmt3+, Skylake events, 32-deep LBR, full-width counters, Intel PMU driver.
... version:                4
... bit width:              48
... generic registers:      4
... value mask:             0000ffffffffffff
... max period:             00007fffffffffff
... fixed-purpose events:   3
... event mask:             000000070000000f
rcu: Hierarchical SRCU implementation.
smp: Bringing up secondary CPUs ...
x86: Booting SMP configuration:
.... node  #0, CPUs:      #1 #2 #3 #4 #5 #6 #7
smp: Brought up 1 node, 8 CPUs
smpboot: Max logical packages: 10
smpboot: Total of 8 processors activated (35221.20 BogoMIPS)
devtmpfs: initialized
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 1911260446275000 ns
futex hash table entries: 2048 (order: 5, 131072 bytes)
xor: automatically using best checksumming function   avx       
pinctrl core: initialized pinctrl subsystem
rcu: INFO: rcu_sched self-detected stall on CPU
rcu:    0-....: (20999 ticks this GP) idle=03e/1/0x4000000000000002 softirq=10/10 fqs=5247 
rcu:     (t=21000 jiffies g=-1175 q=18)
NMI backtrace for cpu 0
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.64 #1
Hardware name: Dell Inc. PowerEdge R640/08HT8T, BIOS 2.2.11 06/13/2019
Call Trace:
 <IRQ>
 0xffffffff81d4c3d5
 0xffffffff81d4f95f
 ? 0xffffffff8102aa32
 0xffffffff81d4f9b8
 0xffffffff8107aafa
 0xffffffff8107a08b
 0xffffffff8107e1e6
 0xffffffff81087ecc
 0xffffffff81e01794
 0xffffffff81e0139f
 </IRQ>
RIP: 0010:0xffffffff8108d4db
Code: ee 89 c7 e8 40 ec cb 00 3b 05 45 63 86 01 73 1e 48 63 f0 49 8b 55 00 48 03 14 f5 00 53 62 82 8b 72 18 40 80 e6 01 74 04 f3 90 <eb> f3 eb d0 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 31 c9 85
RSP: 0000:ffffc9000007fae8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000001
RDX: ffff8897e1063000 RSI: 0000000000000001 RDI: ffff8897e101fc48
RBP: ffff8897e101fc48 R08: 00000000000000ff R09: ffff888000000000
R10: ffffc9000007fb60 R11: 0000000000000001 R12: 000000000001fc00
R13: ffff8897e101fc40 R14: 0000000000000000 R15: ffffffff82625300
 ? 0xffffffff8108d4b9
 ? 0xffffffff8103857d
 ? 0xffffffff8103857d
 0xffffffff8108d507
 0xffffffff8108d51b
 0xffffffff81035988
 0xffffffff81035a8e
 ? 0xffffffff810d853b
 ? 0xffffffff81cb3e73
 ? 0xffffffff81d4c10f
 ? 0xffffffff810cbe08
 0xffffffff81035cb8
 0xffffffff810366f2
 0xffffffff81095dbd
 0xffffffff81cb432c
 ? 0xffffffff82caf70b
 0xffffffff81cb43ea
 ? 0xffffffff82cee8ce
 0xffffffff82cef5c7
 0xffffffff82cee950
 0xffffffff8100040e
 ? 0xffffffff82caf70b
 0xffffffff82cafeed
 ? 0xffffffff81d5c631
 0xffffffff81d5c636
 0xffffffff81e00215

WITH acpi=off and using ttyS1, it still hangs with no output to tty0 or ttyS1.

[Sebastian Roth]

@george1421 said in rcu_sched stall OR kernel panic on PowerEdge R640:

I still have my kernel dev environment setup. What do we need to enable in the kernel for debugging?

First enable CONFIG_EARLY_PRINTK and CONFIG_EARLY_PRINTK_EFI in the kernel config and edit arch/x86/boot/compressed/eboot.c and search for the function called efi_main. Add print statements like efi_printk(sys_table, "Text output\n"); at various places in that function to find out where exactly it locks up.

Then when using the kernel the OP needs to add earlyprintk=efi (or earlyprintk=vga) to the kernel arguments.

[george1421]

@djgalloway This is going to be a bit of a hunt and peck game here.

Remove the apci=off command and lets have it use just one cpu by adding in nosmp as a kernel parameter. It looks like it crashes just after it brings up smp.

Also just for clarity, from the printout this is the processor that is currently in use: Intel(R) Xeon(R) Silver 4114 CPU @ 2.20GHz (family: 0x6, model: 0x55, stepping: 0x4)

[djgalloway]

Kernel command line: loglevel=7 initrd=init.xz root=/dev/ram0 rw ramdisk_size=127000 web=http://10.8.128.2/fog/ consoleblank=0 rootfstype=ext4 console=tty0 console=ttyS1,115200 nosmp mac=e4:43:4b:7d:a9:ba ftp=10.8.128.2 storage=10.8.128.2:/opt/fog/images/dev/ storageip=1p
Misrouted IRQ fixup and polling support enabled
This may significantly impact system performance
Dentry cache hash table entries: 8388608 (order: 14, 67108864 bytes)
Inode-cache hash table entries: 4194304 (order: 13, 33554432 bytes)
Memory: 97288196K/99055148K available (16392K kernel code, 992K rwdata, 4548K rodata, 1056K init, 2416K bss, 1766952K reserved, 0K cma-reserved)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
Kernel/User page tables isolation: enabled
rcu: Hierarchical RCU implementation.
rcu:    RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=1.
rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
NR_IRQS: 4352, nr_irqs: 32, preallocated irqs: 16
Console: colour VGA+ 80x25
console [tty0] enabled
console [ttyS1] enabled
ACPI: Core revision 20180810
ACPI: setting ELCR to 0200 (from 0820)
clocksource: hpet: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 79635855245 ns
APIC: SMP mode deactivated
APIC: Switch to symmetric I/O mode setup in no SMP routine
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD 0 P4D 0 
Oops: 0002 [#1] SMP PTI
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.64 #1
Hardware name: Dell Inc. PowerEdge R640/08HT8T, BIOS 2.2.11 06/13/2019
RIP: 0010:0xffffffff8102d1e6
Code: c2 48 8b 14 d5 00 53 62 82 4a 8b 1c 22 48 85 db 74 d7 3b 2b 75 d3 eb 14 48 8b 1d 25 60 d8 01 48 c7 05 1a 60 d8 01 00 00 00 00 <89> 2b 65 48 89 1d 98 7c fe 7e 65 8b 05 39 1f fe 7e 89 c0 f0 48 0f
RSP: 0000:ffffffff82803e98 EFLAGS: 00010202
RAX: 0000000000000008 RBX: 0000000000000000 RCX: 0000000000000040
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff828f36f0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81408bd7
R10: 0000000000000000 R11: 000000000000005c R12: 0000000000014e88
R13: ffffffff82d460a0 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8897e1000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000002812001 CR4: 00000000000606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 0xffffffff81028ad4
 0xffffffff82cc1652
 0xffffffff82cb691a
 0xffffffff82cafd33
 0xffffffff810000d4
Modules linked in:
CR2: 0000000000000000
---[ end trace f19259880c7c4bbb ]---
RIP: 0010:0xffffffff8102d1e6
Code: c2 48 8b 14 d5 00 53 62 82 4a 8b 1c 22 48 85 db 74 d7 3b 2b 75 d3 eb 14 48 8b 1d 25 60 d8 01 48 c7 05 1a 60 d8 01 00 00 00 00 <89> 2b 65 48 89 1d 98 7c fe 7e 65 8b 05 39 1f fe 7e 89 c0 f0 48 0f
RSP: 0000:ffffffff82803e98 EFLAGS: 00010202
RAX: 0000000000000008 RBX: 0000000000000000 RCX: 0000000000000040
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff828f36f0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81408bd7
R10: 0000000000000000 R11: 000000000000005c R12: 0000000000014e88
R13: ffffffff82d460a0 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8897e1000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000002812001 CR4: 00000000000606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Kernel panic - not syncing: Attempted to kill the idle task!
---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

[Quazz]

We may have to enable kernel config option CONFIG_INTEL_IDLE to improve support for certain Intel CPUs.

We may also want to to bump up CONFIG_NR_CPUS from the default of 8 to 512 (common value on modern kernels) at least on the x64 config, though this one shouldn’t cause a crash.

That said, I am doubtful that would resolve this issue.

[george1421]

@Quazz said in rcu_sched stall OR kernel panic on PowerEdge R640:

We may also want to to bump up CONFIG_NR_CPUS from the default of 8 to 512

I’ve seen this setting in the kernel. I considered requesting the value set to 0 so it uses all available processors, but then I had to think this is for imaging and not a general purposes so having 28 cores available for imaging does really help because at most 4 threads (guess) would be used during imaging since most of the process is single threaded.

[Quazz]

@george1421 Yes, I think that’s why it was left at 8 in the config, though perhaps some CPUs don’t handle a majority of their cores being ignored very well?

[george1421]

@Quazz That is surely something we can test.

[djgalloway]

@george1421 are you working on building a kernel with @Quazz’s suggestions or should I? I don’t have experience building a kernel from scratch but I can probably figure it out.

[george1421]

@djgalloway Sorry I got side tracked this AM. I almost had it built. Give me a few and I’ll send you a link to the kernel via IM chat.