On Tue, Oct 30, 2018 at 03:35:35PM +0000, John Garry wrote:
> [ 7.154740] ERROR: Node-distance not symmetric
> [ 7.154740]
> [ 7.160724] 10 15 20 25
> [ 7.163456] 15 10 25 30
> [ 7.166190] 20 25 10 15
> [ 7.168921] 10 10 15 10
> [ 7.171655]
But I'm not getting the rest of those errors with my 'reproducer':
kvm -smp 4 -m 4G -display none -monitor null -serial stdio -kernel defconfig-build/arch/x86/boot/bzImage -append "sched_debug debug ignore_loglevel earlyprintk=serial,ttyS0,115200,keep numa=fake=4:10,15,20,25,15,10,25,30,20,25,10,15,10,10,15,10,0"
[ 0.828331] ERROR: Node-distance not symmetric
[ 0.828331]
[ 0.829081] 10 15 20 25
[ 0.830079] 15 10 25 30
[ 0.831079] 20 25 10 15
[ 0.832079] 10 10 15 10
[ 0.833079]
[ 0.834373] CPU0 attaching sched-domain(s):
[ 0.835082] domain-0: span=0-3 level=DIE
[ 0.836079] groups: 0:{ span=0 }, 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }
[ 0.837082] CPU1 attaching sched-domain(s):
[ 0.838081] domain-0: span=0-3 level=DIE
[ 0.839079] groups: 1:{ span=1 }, 2:{ span=2 }, 3:{ span=3 }, 0:{ span=0 }
[ 0.840082] CPU2 attaching sched-domain(s):
[ 0.841080] domain-0: span=0-3 level=DIE
[ 0.842079] groups: 2:{ span=2 }, 3:{ span=3 }, 0:{ span=0 }, 1:{ span=1 }
[ 0.843094] ------------[ cut here ]------------
[ 0.844076] kernel BUG at ../mm/slub.c:3901!
[ 0.844083] invalid opcode: 0000 [#1] SMP PTI
[ 0.845076] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc8+ #305
[ 0.845076] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[ 0.845076] RIP: 0010:kfree+0x113/0x160
[ 0.845076] Code: 18 48 89 da 4c 89 e6 e8 db 01 c5 00 48 8b 45 00 48 85 c0 75 e4 e9 0e ff ff ff 49 8b 02 f6 c4 80 75 0a 49 8b 42 08 a8 01 75 02 <0f> 0b 49 8b 02 31 f6 f6 c4 80 74 05 41 0f b6 72 51 5b 5d 41 5c 4c
[ 0.845076] RSP: 0000:ffffabc080633dc8 EFLAGS: 00010246
[ 0.845076] RAX: ffff9f973fff8da0 RBX: ffff9f970000001e RCX: 00000000000000f9
[ 0.845076] RDX: 0000000000000000 RSI: ffff9f963ea23c80 RDI: 0000606980000000
[ 0.845076] RBP: 0000000000020ac0 R08: 0000000000023c80 R09: ffffffff9f8a10db
[ 0.845076] R10: fffff17204000000 R11: 0000000000000001 R12: ffffffff9f8a113d
[ 0.845076] R13: 0000000000000003 R14: ffffffffa0ab4820 R15: ffff9f973e5bde00
[ 0.845076] FS: 0000000000000000(0000) GS:ffff9f963ea00000(0000) knlGS:0000000000000000
[ 0.845076] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.845076] CR2: 00000000ffffffff CR3: 000000008ea0a000 CR4: 00000000000006f0
[ 0.845076] Call Trace:
[ 0.845076] destroy_sched_domain+0x3d/0x50
[ 0.845076] cpu_attach_domain+0x378/0x680
[ 0.845076] ? update_group_capacity+0x20/0x2c0
[ 0.845076] build_sched_domains+0xde9/0xed0
[ 0.845076] ? set_debug_rodata+0xc/0xc
[ 0.845076] sched_init_domains+0x80/0x90
[ 0.845076] sched_init_smp+0x1d/0x63
[ 0.845076] kernel_init_freeable+0x101/0x23f
[ 0.845076] ? rest_init+0xb0/0xb0
[ 0.845076] kernel_init+0x5/0x100
[ 0.845076] ret_from_fork+0x35/0x40
I'll work on that crash though..
> I also note that if I apply the patch, below, to reject the invalid NUMA
> distance, we're still getting a warning/error:
>
> [ 7.144407] CPU: All CPU(s) started at EL2
> [ 7.148678] alternatives: patching kernel code
> [ 7.153557] ERROR: Node-0 not representative
> [ 7.153557]
> [ 7.159365] 10 15 20 25
> [ 7.162097] 15 10 25 30
> [ 7.164832] 20 25 10 15
> [ 7.167562] 25 30 15 10
Yeah, that's an 'obviously' broken topology too.
Clearly you're far more creative than the ACPI BIOS people have been so
far.
