linux/arch/powerpc/mm
Srikar Dronamraju ac1788cc7d powerpc/numa: Skip onlining a offline node in kdump path
With commit 2ea6263068 ("powerpc/topology: Get topology for shared
processors at boot"), kdump kernel on shared LPAR may crash.

The necessary conditions are
- Shared LPAR with at least 2 nodes having memory and CPUs.
- Memory requirement for kdump kernel must be met by the first N-1
  nodes where there are at least N nodes with memory and CPUs.

Example numactl of such a machine.
  $ numactl -H
  available: 5 nodes (0,2,5-7)
  node 0 cpus:
  node 0 size: 0 MB
  node 0 free: 0 MB
  node 2 cpus:
  node 2 size: 255 MB
  node 2 free: 189 MB
  node 5 cpus: 24 25 26 27 28 29 30 31
  node 5 size: 4095 MB
  node 5 free: 4024 MB
  node 6 cpus: 0 1 2 3 4 5 6 7 16 17 18 19 20 21 22 23
  node 6 size: 6353 MB
  node 6 free: 5998 MB
  node 7 cpus: 8 9 10 11 12 13 14 15 32 33 34 35 36 37 38 39
  node 7 size: 7640 MB
  node 7 free: 7164 MB
  node distances:
  node   0   2   5   6   7
    0:  10  40  40  40  40
    2:  40  10  40  40  40
    5:  40  40  10  40  40
    6:  40  40  40  10  20
    7:  40  40  40  20  10

Steps to reproduce.
1. Load / start kdump service.
2. Trigger a kdump (for example : echo c > /proc/sysrq-trigger)

When booting a kdump kernel with 2048M:

  kexec: Starting switchover sequence.
  I'm in purgatory
  Using 1TB segments
  hash-mmu: Initializing hash mmu with SLB
  Linux version 4.19.0-rc5-master+ (srikar@linux-xxu6) (gcc version 4.8.5 (SUSE Linux)) #1 SMP Thu Sep 27 19:45:00 IST 2018
  Found initrd at 0xc000000009e70000:0xc00000000ae554b4
  Using pSeries machine description
  -----------------------------------------------------
  ppc64_pft_size    = 0x1e
  phys_mem_size     = 0x88000000
  dcache_bsize      = 0x80
  icache_bsize      = 0x80
  cpu_features      = 0x000000ff8f5d91a7
    possible        = 0x0000fbffcf5fb1a7
    always          = 0x0000006f8b5c91a1
  cpu_user_features = 0xdc0065c2 0xef000000
  mmu_features      = 0x7c006001
  firmware_features = 0x00000007c45bfc57
  htab_hash_mask    = 0x7fffff
  physical_start    = 0x8000000
  -----------------------------------------------------
  numa:   NODE_DATA [mem 0x87d5e300-0x87d67fff]
  numa:     NODE_DATA(0) on node 6
  numa:   NODE_DATA [mem 0x87d54600-0x87d5e2ff]
  Top of RAM: 0x88000000, Total RAM: 0x88000000
  Memory hole size: 0MB
  Zone ranges:
    DMA      [mem 0x0000000000000000-0x0000000087ffffff]
    DMA32    empty
    Normal   empty
  Movable zone start for each node
  Early memory node ranges
    node   6: [mem 0x0000000000000000-0x0000000087ffffff]
  Could not find start_pfn for node 0
  Initmem setup node 0 [mem 0x0000000000000000-0x0000000000000000]
  On node 0 totalpages: 0
  Initmem setup node 6 [mem 0x0000000000000000-0x0000000087ffffff]
  On node 6 totalpages: 34816

  Unable to handle kernel paging request for data at address 0x00000060
  Faulting instruction address: 0xc000000008703a54
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 11 PID: 1 Comm: swapper/11 Not tainted 4.19.0-rc5-master+ #1
  NIP:  c000000008703a54 LR: c000000008703a38 CTR: 0000000000000000
  REGS: c00000000b673440 TRAP: 0380   Not tainted  (4.19.0-rc5-master+)
  MSR:  8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 24022022  XER: 20000002
  CFAR: c0000000086fc238 IRQMASK: 0
  GPR00: c000000008703a38 c00000000b6736c0 c000000009281900 0000000000000000
  GPR04: 0000000000000000 0000000000000000 fffffffffffff001 c00000000b660080
  GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000220
  GPR12: 0000000000002200 c000000009e51400 0000000000000000 0000000000000008
  GPR16: 0000000000000000 c000000008c152e8 c000000008c152a8 0000000000000000
  GPR20: c000000009422fd8 c000000009412fd8 c000000009426040 0000000000000008
  GPR24: 0000000000000000 0000000000000000 c000000009168bc8 c000000009168c78
  GPR28: c00000000b126410 0000000000000000 c00000000916a0b8 c00000000b126400
  NIP [c000000008703a54] bus_add_device+0x84/0x1e0
  LR [c000000008703a38] bus_add_device+0x68/0x1e0
  Call Trace:
  [c00000000b6736c0] [c000000008703a38] bus_add_device+0x68/0x1e0 (unreliable)
  [c00000000b673740] [c000000008700194] device_add+0x454/0x7c0
  [c00000000b673800] [c00000000872e660] __register_one_node+0xb0/0x240
  [c00000000b673860] [c00000000839a6bc] __try_online_node+0x12c/0x180
  [c00000000b673900] [c00000000839b978] try_online_node+0x58/0x90
  [c00000000b673930] [c0000000080846d8] find_and_online_cpu_nid+0x158/0x190
  [c00000000b673a10] [c0000000080848a0] numa_update_cpu_topology+0x190/0x580
  [c00000000b673c00] [c000000008d3f2e4] smp_cpus_done+0x94/0x108
  [c00000000b673c70] [c000000008d5c00c] smp_init+0x174/0x19c
  [c00000000b673d00] [c000000008d346b8] kernel_init_freeable+0x1e0/0x450
  [c00000000b673dc0] [c0000000080102e8] kernel_init+0x28/0x160
  [c00000000b673e30] [c00000000800b65c] ret_from_kernel_thread+0x5c/0x80
  Instruction dump:
  60000000 60000000 e89e0020 7fe3fb78 4bff87d5 60000000 7c7d1b79 4082008c
  e8bf0050 e93e0098 3b9f0010 2fa50000 <e8690060> 38630018 419e0114 7f84e378
  ---[ end trace 593577668c2daa65 ]---

However a regular kernel with 4096M (2048 gets reserved for crash
kernel) boots properly.

Unlike regular kernels, which mark all available nodes as online,
kdump kernel only marks just enough nodes as online and marks the rest
as offline at boot. However kdump kernel boots with all available
CPUs. With Commit 2ea6263068 ("powerpc/topology: Get topology for
shared processors at boot"), all CPUs are onlined on their respective
nodes at boot time. try_online_node() tries to online the offline
nodes but fails as all needed subsystems are not yet initialized.

As part of fix, detect and skip early onlining of a offline node.

Fixes: 2ea6263068 ("powerpc/topology: Get topology for shared processors at boot")
Reported-by: Pavithra Prakash <pavrampu@in.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-05 23:21:54 +10:00
..
8xx_mmu.c powerpc/mm/slice: Fix hugepage allocation at hint address on 8xx 2018-03-06 09:21:23 +11:00
40x_mmu.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
44x_mmu.c powerpc/44x: Mark mmu_init_secondary() as __init 2018-07-30 22:48:22 +10:00
copro_fault.c mm: convert return type of handle_mm_fault() caller to vm_fault_t 2018-08-17 16:20:28 -07:00
dma-noncoherent.c powerpc/mm: Rename map_page() to map_kernel_page() on 32-bit 2017-06-05 19:59:03 +10:00
drmem.c powerpc/mm/drmem: Fix unexpected flag value in ibm,dynamic-memory-v2 2018-02-23 16:45:51 +11:00
dump_hashpagetable.c powerpc: remove superflous inclusions of asm/fixmap.h 2018-07-30 22:48:18 +10:00
dump_linuxpagetables.c powerpc/mm: Introduce _PAGE_NA 2018-01-16 23:47:14 +11:00
fault.c Merge branch 'akpm' (patches from Andrew) 2018-08-17 16:49:31 -07:00
fsl_booke_mmu.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
hash64_4k.c powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group 2018-07-24 22:03:17 +10:00
hash64_64k.c powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group 2018-07-24 22:03:17 +10:00
hash_low_32.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
hash_native_64.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
hash_utils_64.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
highmem.c powerpc/mm: remove warning about ‘type’ being set 2018-08-10 22:12:38 +10:00
hugepage-hash64.c powerpc/mm/hash: Remove the superfluous bitwise operation when find hpte group 2018-07-24 22:03:17 +10:00
hugetlbpage-book3e.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hugetlbpage-hash64.c powerpc/mm/hash64: Store the slot information at the right offset for hugetlb 2018-02-13 22:37:48 +11:00
hugetlbpage-radix.c powerpc updates for 4.15 2017-11-16 12:47:46 -08:00
hugetlbpage.c powerpc/hugetlbpage: Rmove unhelpful HUGEPD_*_SHIFT macros 2018-07-19 14:38:46 +10:00
init_32.c powerpc/mm/32: Remove the reserved memory hack 2018-04-01 00:47:44 +11:00
init_64.c powerpc/mm/radix: Parse disable_radix commandline correctly. 2018-04-04 16:59:36 +10:00
init-common.c powerpc/mm: Fix crashes with 16G huge pages 2018-02-13 22:37:47 +11:00
Makefile powerpc/Makefiles: Convert ifeq to ifdef where possible 2018-08-08 00:32:36 +10:00
mem.c powerpc: Avoid code patching freed init sections 2018-09-18 22:42:54 +10:00
mmap.c exec: pass stack rlimit into mm layout functions 2018-04-11 10:28:37 -07:00
mmu_context_book3s64.c Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax 2018-08-26 11:48:42 -07:00
mmu_context_hash32.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
mmu_context_iommu.c KVM: PPC: Book3S: Fix guest DMA when guest partially backed by THP pages 2018-08-23 23:40:10 +10:00
mmu_context_nohash.c powerpc/mm: Remove stale_map[] handling on non SMP processors 2018-06-04 00:39:16 +10:00
mmu_context.c powerpc/64s/radix: optimise pte_update 2018-06-03 20:40:36 +10:00
mmu_decl.h powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
numa.c powerpc/numa: Skip onlining a offline node in kdump path 2018-10-05 23:21:54 +10:00
pgtable_32.c powerpc/mm/32: Remove the reserved memory hack 2018-04-01 00:47:44 +11:00
pgtable_64.c powerpc/mm: Use page fragments for allocation page table at PMD level 2018-05-15 22:29:12 +10:00
pgtable-book3e.c powerpc/mm: Make page table size a variable 2016-05-01 18:32:48 +10:00
pgtable-book3s64.c powerpc/mm/book3s/radix: Add mapping statistics 2018-08-13 16:35:05 +10:00
pgtable-hash64.c powerpc/mm: Use pmd_lockptr instead of opencoding it 2018-05-15 22:29:09 +10:00
pgtable-radix.c powerpc/mm/radix: Only need the Nest MMU workaround for R -> RW transition 2018-08-23 21:56:48 +10:00
pgtable.c powerpc/mm/hugetlb: Update hugetlb related locks 2018-06-03 20:40:37 +10:00
pkeys.c powerpc/pkeys: Fix reading of ibm, processor-storage-keys property 2018-09-20 22:49:46 +10:00
ppc_mmu_32.c powerpc/sparse: Fix plain integer as NULL pointer warning 2018-05-25 12:04:38 +10:00
slb_low.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
slb.c powerpc/mce: Fix SLB rebolting during MCE recovery path. 2018-08-23 23:40:10 +10:00
slice.c powerpc/8xx: Fix build with hugetlbfs enabled 2018-04-11 12:00:23 +10:00
subpage-prot.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
tlb_hash32.c powerpc/sparse: Fix plain integer as NULL pointer warning 2018-05-25 12:04:38 +10:00
tlb_hash64.c powerpc/mm: Add support for handling > 512TB address in SLB miss 2018-03-31 00:10:38 +11:00
tlb_low_64e.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
tlb_nohash_low.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
tlb_nohash.c powerpc/mm/nohash: do not flush the entire mm when range is a single page 2018-01-27 20:24:44 +11:00
tlb-radix.c Merge branch 'topic/ppc-kvm' into next 2018-07-19 14:37:57 +10:00
vphn.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vphn.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00