On 10/01/2014 04:20 PM, Linus Torvalds wrote:
> So I'm really sending this patch out in the hope that it will get
> comments, fixup and possibly even testing by people who actually know
> the NUMA balancing code. Rik? Anybody?
Hi Linus,
I've tried this patch on the same configuration that was triggering
the VM_BUG_ON that Hugh mentioned previously. Surprisingly enough it
ran fine for ~20 minutes before exploding with:
[ 2781.566206] kernel BUG at mm/huge_memory.c:1293!
[ 2781.566953] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 2781.568054] Dumping ftrace buffer:
[ 2781.568826] (ftrace buffer empty)
[ 2781.569392] Modules linked in:
[ 2781.569909] CPU: 61 PID: 13111 Comm: trinity-c61 Not tainted
3.17.0-rc7-sasha-00040-g65e1cb2 #1259
[ 2781.571077] task: ffff88050ba80000 ti: ffff880418ecc000 task.ti:
ffff880418ecc000
[ 2781.571077] RIP: do_huge_pmd_numa_page (mm/huge_memory.c:1293 (discriminator
1))
[ 2781.571077] RSP: 0000:ffff880418ecfc60 EFLAGS: 00010246
[ 2781.571077] RAX: ffffea0074c60000 RBX: ffffea0074c60000 RCX: 0000001d318009e0
[ 2781.571077] RDX: ffffea0000000000 RSI: ffffffffb5706ef3 RDI: 0000001d318009e0
[ 2781.571077] RBP: ffff880418ecfcc8 R08: 0000000000000038 R09: 0000000000000001
[ 2781.571077] R10: 0000000000000038 R11: 0000000000000001 R12: ffff8804f9b52000
[ 2781.571077] R13: 0000001d318009e0 R14: ffff880508a1f840 R15: 0000000000000028
[ 2781.571077] FS: 00007f5502fc9700(0000) GS:ffff881d77e00000(0000)
knlGS:0000000000000000
[ 2781.571077] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2781.571077] CR2: 0000000000000000 CR3: 00000004bfac4000 CR4: 00000000000006a0
[ 2781.571077] Stack:
[ 2781.571077] ffff880418ecfc98 0000000000000282 ffff88050ba80000
000000000000000b
[ 2781.571077] ffff88060d2ab000 ffff88060000001d 0000000000000000
ffff881d30b3ec00
[ 2781.571077] 0000000000000000 ffff881d30b3ec00 ffff88060d2ab000
0000000000000100
[ 2781.571077] Call Trace:
[ 2781.571077] handle_mm_fault (mm/memory.c:3304 mm/memory.c:3368)
[ 2781.571077] __do_page_fault (arch/x86/mm/fault.c:1231)
[ 2781.571077] ? kvm_clock_read (./arch/x86/include/asm/preempt.h:90
arch/x86/kernel/kvmclock.c:86)
[ 2781.571077] ? sched_clock (./arch/x86/include/asm/paravirt.h:192
arch/x86/kernel/tsc.c:304)
[ 2781.571077] ? sched_clock_local (kernel/sched/clock.c:214)
[ 2781.571077] ? context_tracking_user_exit (kernel/context_tracking.c:184)
[ 2781.571077] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63)
[ 2781.571077] ? trace_hardirqs_off_caller (kernel/locking/lockdep.c:2641
(discriminator 8))
[ 2781.571077] trace_do_page_fault (arch/x86/mm/fault.c:1314
include/linux/jump_label.h:115 include/linux/context_tracking_state.h:27
include/linux/context_tracking.h:45 arch/x86/mm/fault.c:1315)
[ 2781.571077] do_async_page_fault (arch/x86/kernel/kvm.c:279)
[ 2781.571077] async_page_fault (arch/x86/kernel/entry_64.S:1314)
[ 2781.571077] ? copy_user_generic_unrolled (arch/x86/lib/copy_user_64.S:166)
[ 2781.571077] ? sys32_mmap (arch/x86/ia32/sys_ia32.c:159)
[ 2781.571077] ia32_do_call (arch/x86/ia32/ia32entry.S:430)
[ 2781.571077] Code: b4 eb e0 0f 1f 84 00 00 00 00 00 4c 89 f7 e8 88 2f 0c 03
48 8b 45 d0 4c 89 e6 48 8b b8 88 00 00 00 e8 85 c7 ff ff e9 90 fe ff ff <0f> 0b
66 0f 1f 44 00 00 48 89 df e8 90 e9 f9 ff 84 c0 0f 85 be
All code
========
0: b4 eb mov $0xeb,%ah
2: e0 0f loopne 0x13
4: 1f (bad)
5: 84 00 test %al,(%rax)
7: 00 00 add %al,(%rax)
9: 00 00 add %al,(%rax)
b: 4c 89 f7 mov %r14,%rdi
e: e8 88 2f 0c 03 callq 0x30c2f9b
13: 48 8b 45 d0 mov -0x30(%rbp),%rax
17: 4c 89 e6 mov %r12,%rsi
1a: 48 8b b8 88 00 00 00 mov 0x88(%rax),%rdi
21: e8 85 c7 ff ff callq 0xffffffffffffc7ab
26: e9 90 fe ff ff jmpq 0xfffffffffffffebb
2b:* 0f 0b ud2 <-- trapping instruction
2d: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
33: 48 89 df mov %rbx,%rdi
36: e8 90 e9 f9 ff callq 0xfffffffffff9e9cb
3b: 84 c0 test %al,%al
3d: 0f .byte 0xf
3e: 85 .byte 0x85
3f: be .byte 0xbe
...
Code starting with the faulting instruction
===========================================
0: 0f 0b ud2
2: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
8: 48 89 df mov %rbx,%rdi
b: e8 90 e9 f9 ff callq 0xfffffffffff9e9a0
10: 84 c0 test %al,%al
12: 0f .byte 0xf
13: 85 .byte 0x85
14: be .byte 0xbe
...
[ 2781.571077] RIP do_huge_pmd_numa_page (mm/huge_memory.c:1293 (discriminator
1))
[ 2781.571077] RSP <ffff880418ecfc60>
Thanks,
Sasha
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