korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2025-01-06 22:04:22 +08:00
Code Issues Packages Projects Releases Wiki Activity
a1e2b8b368
linux/arch/x86
History
Mike Rapoport (IBM) a1e2b8b368 x86/mm: Drop the 4 MB restriction on minimal NUMA node memory size 
Qi Zheng reported crashes in a production environment and provided a
simplified example as a reproducer:

 |  For example, if we use Qemu to start a two NUMA node kernel,
 |  one of the nodes has 2M memory (less than NODE_MIN_SIZE),
 |  and the other node has 2G, then we will encounter the
 |  following panic:
 |
 |    BUG: kernel NULL pointer dereference, address: 0000000000000000
 |    <...>
 |    RIP: 0010:_raw_spin_lock_irqsave+0x22/0x40
 |    <...>
 |    Call Trace:
 |      <TASK>
 |      deactivate_slab()
 |      bootstrap()
 |      kmem_cache_init()
 |      start_kernel()
 |      secondary_startup_64_no_verify()

The crashes happen because of inconsistency between the nodemask that
has nodes with less than 4MB as memoryless, and the actual memory fed
into the core mm.

The commit:

  9391a3f9c7 ("[PATCH] x86_64: Clear more state when ignoring empty node in SRAT parsing")

... that introduced minimal size of a NUMA node does not explain why
a node size cannot be less than 4MB and what boot failures this
restriction might fix.

Fixes have been submitted to the core MM code to tighten up the
memory topologies it accepts and to not crash on weird input:

  mm: page_alloc: skip memoryless nodes entirely
  mm: memory_hotplug: drop memoryless node from fallback lists

Andrew has accepted them into the -mm tree, but there are no
stable SHA1's yet.

This patch drops the limitation for minimal node size on x86:

  - which works around the crash without the fixes to the core MM.
  - makes x86 topologies less weird,
  - removes an arbitrary and undocumented limitation on NUMA topologies.

[ mingo: Improved changelog clarity. ]

Reported-by: Qi Zheng <zhengqi.arch@bytedance.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rik van Riel <riel@surriel.com>
Link: https://lore.kernel.org/r/ZS+2qqjEO5/867br@gmail.com
2023-10-20 10:40:22 +02:00
..
boot x86/sev: Make boot_ghcb_page[] static 2023-10-03 15:31:27 +02:00
coco x86/tdx: Replace deprecated strncpy() with strtomem_pad() 2023-10-04 09:34:07 +02:00
configs - The first, cleanup part of the microcode loader reorg tglx has been 2023-08-28 15:55:20 -07:00
crypto crypto: x86/aesni - remove unused parameter to aes_set_key_common() 2023-07-22 13:59:39 +12:00
entry Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
events perf/x86/uncore: Correct the number of CHAs on EMR 2023-09-05 21:50:21 +02:00
hyperv hyperv-next for v6.6 2023-09-04 11:26:29 -07:00
ia32
include x86/mm: Drop the 4 MB restriction on minimal NUMA node memory size 2023-10-20 10:40:22 +02:00
kernel x86/sev: Move sev_setup_arch() to mem_encrypt.c 2023-10-11 10:15:47 +02:00
kvm ARM: 2023-09-07 13:52:20 -07:00
lib x86: bring back rep movsq for user access on CPUs without ERMS 2023-08-30 09:45:12 -07:00
math-emu x86/fpu: Include asm/fpu/regset.h 2023-05-18 11:56:18 -07:00
mm x86/mm: Drop the 4 MB restriction on minimal NUMA node memory size 2023-10-20 10:40:22 +02:00
net bpf: Support new 32bit offset jmp instruction 2023-07-27 18:52:33 -07:00
pci pci-v6.6-changes 2023-08-30 20:23:07 -07:00
platform * Rework apic callbacks, getting rid of unnecessary ones and 2023-08-30 10:44:46 -07:00
power x86/topology: Remove CPU0 hotplug option 2023-05-15 13:44:49 +02:00
purgatory x86/purgatory: Include header for warn() declaration 2023-08-03 16:37:18 +02:00
ras
realmode x86/realmode: Make stack lock work in trampoline_compat() 2023-05-30 14:11:47 +02:00
tools ELF: fix all "Elf" typos 2023-04-08 13:45:37 -07:00
um um: Hard-code the result of 'uname -s' 2023-08-26 22:40:37 +02:00
video Merge drm/drm-next into drm-misc-next 2023-07-24 15:44:47 +02:00
virt/vmx/tdx
xen Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
.gitignore
Kbuild
Kconfig Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
Kconfig.assembler x86/shstk: Add Kconfig option for shadow stack 2023-07-11 14:12:18 -07:00
Kconfig.cpu x86/cpu: Remove X86_FEATURE_NAMES 2023-05-15 20:03:08 +02:00
Kconfig.debug docs: move x86 documentation into Documentation/arch/ 2023-03-30 12:58:51 -06:00
Makefile Kbuild updates for v6.6 2023-09-05 11:01:47 -07:00
Makefile_32.cpu
Makefile.postlink x86/build: Avoid relocation information in final vmlinux 2023-06-14 19:54:40 +02:00
Makefile.um um: Only disable SSE on clang to work around old GCC bugs 2023-04-04 09:57:05 +02:00