Hi there,
I have recently bought an Intel NUC6i3SYB. That's essentially a small
form-factor x86_64 PC. That device runs Linux Mint. Unfortunately I see
frequent kernel oopses within the ext4 subsystem and consequently loss
of data, corrupted files and complete system crashes. Here's a recent
call trace:
[ 796.429566] systemd[1]: apt-daily.timer: Adding 4h 1min 3.723928s
random time.
[ 3405.666456] general protection fault: 0000 [#1] SMP
[ 3405.666519] Modules linked in: rfcomm bnep binfmt_misc
snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic arc4
snd_soc_skl snd_soc_skl_ipc snd_hda_ext_core iwlmvm snd_soc_sst_ipc
snd_soc_sst_dsp snd_soc_core mac80211 btusb snd_compress btrtl ac97_bus
snd_pcm_dmaengine dw_dmac_core snd_hda_intel snd_hda_codec snd_hda_core
8250_dw snd_hwdep intel_rapl snd_pcm x86_pkg_temp_thermal
intel_powerclamp coretemp iwlwifi snd_seq_midi snd_seq_midi_event
kvm_intel snd_rawmidi hci_uart btbcm btqca snd_seq cfg80211
snd_seq_device kvm btintel bluetooth snd_timer irqbypass
ir_sharp_decoder ir_rc5_decoder snd ir_lirc_codec ir_jvc_decoder
ir_xmp_decoder lirc_dev ir_mce_kbd_decoder ir_sanyo_decoder
ir_rc6_decoder ir_sony_decoder ir_nec_decoder rc_rc6_mce soundcore
ite_cir intel_lpss_acpi mei_me rc_core
[ 3405.667326] idma64 virt_dma shpchp intel_lpss_pci intel_lpss mei
acpi_pad acpi_als kfifo_buf industrialio mac_hid parport_pc ppdev lp
parport autofs4 btrfs xor raid6_pq jitterentropy_rng drbg ansi_cprng
dm_crypt algif_skcipher af_alg dm_mirror dm_region_hash dm_log
crct10dif_pclmul crc32_pclmul i915_bpo intel_ips i2c_algo_bit
drm_kms_helper aesni_intel syscopyarea sysfillrect aes_x86_64 lrw
gf128mul glue_helper sysimgblt ablk_helper e1000e fb_sys_fops sdhci_pci
cryptd ahci ptp i2c_hid drm pps_core libahci sdhci pinctrl_sunrisepoint
video hid pinctrl_intel fjes
[ 3405.667929] CPU: 3 PID: 2261 Comm: hexchat Not tainted
4.4.0-21-generic #37-Ubuntu
[ 3405.667998] Hardware name: /NUC6i3SYB, BIOS
SYSKLi35.86A.0042.2016.0409.1246 04/09/2016
[ 3405.668082] task: ffff88003565ac40 ti: ffff8804332e8000 task.ti:
ffff8804332e8000
[ 3405.668148] RIP: 0010:[<ffffffff811eb027>] [<ffffffff811eb027>]
kmem_cache_alloc+0x77/0x1f0
[ 3405.668234] RSP: 0018:ffff8804332eba88 EFLAGS: 00010282
[ 3405.668282] RAX: 0000000000000000 RBX: 0000000002408040 RCX:
00000000000e1547
[ 3405.668345] RDX: 00000000000e1546 RSI: 0000000002408040 RDI:
000000000001a940
[ 3405.668408] RBP: ffff8804332ebab8 R08: ffff88046ed9a940 R09:
ffdb88033bb3a3a8
[ 3405.668470] R10: ffff8804591a4ed0 R11: ffffffff81ccc462 R12:
0000000002408040
[ 3405.668533] R13: ffffffff81243351 R14: ffff88045e08bc00 R15:
ffff88045e08bc00
[ 3405.668597] FS: 00007f1df9704a40(0000) GS:ffff88046ed80000(0000)
knlGS:0000000000000000
[ 3405.668668] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3405.668719] CR2: 00007fd945ecebd6 CR3: 0000000456a48000 CR4:
00000000003406e0
[ 3405.668782] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 3405.668844] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[ 3405.668906] Stack:
[ 3405.668926] 01ff880438ee2508 0000000000001000 ffff8803344df000
ffffea000cd137c0
[ 3405.669003] 0000000000000000 0000000000000000 ffff8804332ebad0
ffffffff81243351
[ 3405.669080] ffff8800354bd024 ffff8804332ebb18 ffffffff81243829
00000001332ebb70
[ 3405.669156] Call Trace:
[ 3405.669186] [<ffffffff81243351>] alloc_buffer_head+0x21/0x60
[ 3405.669240] [<ffffffff81243829>] alloc_page_buffers+0x79/0xe0
[ 3405.669294] [<ffffffff812438ae>] create_empty_buffers+0x1e/0xc0
[ 3405.669351] [<ffffffff812979cc>] ext4_block_write_begin+0x3cc/0x4d0
[ 3405.669410] [<ffffffff812e74db>] ? jbd2__journal_start+0xdb/0x1e0
[ 3405.669469] [<ffffffff81296e10>] ?
ext4_inode_attach_jinode.part.60+0xb0/0xb0
[ 3405.669536] [<ffffffff812cb83d>] ? __ext4_journal_start_sb+0x6d/0x120
[ 3405.669596] [<ffffffff8129d574>] ext4_da_write_begin+0x154/0x320
[ 3405.669656] [<ffffffff8118d4de>] generic_perform_write+0xce/0x1c0
[ 3405.669713] [<ffffffff8118f382>] __generic_file_write_iter+0x1a2/0x1e0
[ 3405.669773] [<ffffffff81291ffc>] ext4_file_write_iter+0xfc/0x460
[ 3405.669833] [<ffffffff81794d6e>] ? inet_recvmsg+0x7e/0xb0
[ 3405.669885] [<ffffffff816fdb6b>] ? sock_recvmsg+0x3b/0x50
[ 3405.669938] [<ffffffff8120bedb>] new_sync_write+0x9b/0xe0
[ 3405.669990] [<ffffffff8120bf46>] __vfs_write+0x26/0x40
[ 3405.670040] [<ffffffff8120c8c9>] vfs_write+0xa9/0x1a0
[ 3405.672397] [<ffffffff8120c776>] ? vfs_read+0x86/0x130
[ 3405.674693] [<ffffffff8120d585>] SyS_write+0x55/0xc0
[ 3405.676925] [<ffffffff818244f2>] entry_SYSCALL_64_fastpath+0x16/0x71
[ 3405.679111] Code: 08 65 4c 03 05 83 f1 e1 7e 49 83 78 10 00 4d 8b 08
0f 84 29 01 00 00 4d 85 c9 0f 84 20 01 00 00 49 63 47 20 48 8d 4a 01 49
8b 3f <49> 8b 1c 01 4c 89 c8 65 48 0f c7 0f 0f 94 c0 84 c0 74 bb 49 63
[ 3405.683725] RIP [<ffffffff811eb027>] kmem_cache_alloc+0x77/0x1f0
[ 3405.685876] RSP <ffff8804332eba88>
[ 3405.696001] ---[ end trace 4968a9119e168c92 ]---
After this occurs, the system becomes extremely unstable, i.e., the
filesystem cannot be read properly anymore (e.g., ssh logins usually do
not work anymore, most binaries just segfault). After a reboot (which
has to be done manually, "shutdown -r now" also segfaults) it works fine
again (until the problem comes back).
Since the hardware is fairly new, I cannot exclude a hardware defect as
of now. I've thouroughly tested the RAM though and not found any defect
there (ran MemTest86+ for 24 hours). One curious thing is that someone
else seems to have run into this before. Searching for the symbols in
the stackframe I came upon this:
http://pastebin.com/BJbu35H4
Which, quoting in full:
Jul 16 14:28:29 nuc kernel: [ 370.642612] general protection fault:
0000 [#1] SMP
Jul 16 14:28:29 nuc kernel: [ 370.642657] Modules linked in: arc4
intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel
iwlmvm kvm mac80211 irqbypass crct10dif_pclmul crc32_pclmul iwlwifi
aesni_intel aes_x86_64 snd_hda_codec_hdmi btusb btrtl
snd_hda_codec_realtek btbcm btintel lrw gf128mul snd_hda_codec_generic
ir_xmp_decoder glue_helper ablk_helper ir_lirc_codec cryptd mei_me
lirc_dev ir_mce_kbd_decoder ir_sharp_decoder ir_sanyo_decoder bluetooth
cfg80211 snd_hda_intel ir_sony_decoder mei ir_jvc_decoder ir_rc6_decoder
ir_rc5_decoder ir_nec_decoder lpc_ich snd_hda_codec shpchp
snd_soc_rt5640 snd_hda_core snd_soc_rl6231 snd_hwdep snd_soc_core
snd_compress ac97_bus snd_pcm_dmaengine rc_rc6_mce dw_dmac snd_pcm
nuvoton_cir rc_core snd_timer dw_dmac_core snd elan_i2c soundcore
snd_soc_sst_acpi spi_pxa2xx_platform i2c_designware_platform
i2c_designware_core 8250_dw mac_hid ip6t_REJECT nf_reject_ipv6
nf_log_ipv6 xt_hl ip6t_rt nf_conntrack_ipv6 nf_defrag_ipv6 ipt_REJECT
nf_reject_ipv4 xt_comment nf_log_ipv4 nf_log_common xt_LOG xt_multiport
xt_limit xt_tcpudp xt_addrtype nf_conntrack_ipv4 nf_defrag_ipv4
xt_conntrack ip6table_filter ip6_tables nf_conntrack_netbios_ns
nf_conntrack_broadcast nf_nat_ftp nf_nat sunrpc nf_conntrack_ftp
nf_conntrack iptable_filter ip_tables x_tables autofs4 btrfs xor
raid6_pq i915 i2c_algo_bit drm_kms_helper e1000e syscopyarea sysfillrect
sysimgblt uas fb_sys_fops ptp ahci sdhci_acpi usb_storage libahci drm
pps_core video i2c_hid sdhci hid fjes
Jul 16 14:28:29 nuc kernel: [ 370.643778] CPU: 3 PID: 1505 Comm: dd Not
tainted 4.4.0-31-generic #50-Ubuntu
Jul 16 14:28:29 nuc kernel: [ 370.643822] Hardware name:
/D54250WYK, BIOS WYLPT10H.86A.0041.2015.0720.1108 07/20/2015
Jul 16 14:28:29 nuc kernel: [ 370.643878] task: ffff88040aa90000 ti:
ffff880407b98000 task.ti: ffff880407b98000
Jul 16 14:28:29 nuc kernel: [ 370.643923] RIP:
0010:[<ffffffff811eb987>] [<ffffffff811eb987>] kmem_cache_alloc+0x77/0x1f0
Jul 16 14:28:29 nuc kernel: [ 370.643982] RSP: 0018:ffff880407b9ba80
EFLAGS: 00010282
Jul 16 14:28:29 nuc kernel: [ 370.644015] RAX: 0000000000000000 RBX:
0000000002408040 RCX: 00000000000bb283
Jul 16 14:28:29 nuc kernel: [ 370.644054] RDX: 00000000000bb282 RSI:
0000000002408040 RDI: 000000000001a940
Jul 16 14:28:29 nuc kernel: [ 370.644076] RBP: ffff880407b9bab0 R08:
ffff88041fb9a940 R09: ddff88007f5aff08
Jul 16 14:28:29 nuc kernel: [ 370.644097] R10: ffff8800d522d060 R11:
ffffffff81ccf1ea R12: 0000000002408040
Jul 16 14:28:29 nuc kernel: [ 370.644119] R13: ffffffff81243ea1 R14:
ffff88040f08bc00 R15: ffff88040f08bc00
Jul 16 14:28:29 nuc kernel: [ 370.644141] FS: 00007fa227587700(0000)
GS:ffff88041fb80000(0000) knlGS:0000000000000000
Jul 16 14:28:29 nuc kernel: [ 370.644165] CS: 0010 DS: 0000 ES: 0000
CR0: 0000000080050033
Jul 16 14:28:29 nuc kernel: [ 370.644183] CR2: 0000000000a08000 CR3:
000000040aaac000 CR4: 00000000001406e0
Jul 16 14:28:29 nuc kernel: [ 370.644205] Stack:
Jul 16 14:28:29 nuc kernel: [ 370.644213] 01ff8803fef10a00
0000000000001000 ffff88007b89f000 ffffea0001ee27c0
Jul 16 14:28:29 nuc kernel: [ 370.644241] 0000000000000000
0000000000000000 ffff880407b9bac8 ffffffff81243ea1
Jul 16 14:28:29 nuc kernel: [ 370.644270] ffff8804099b8024
ffff880407b9bb10 ffffffff81244379 0000000107b9bb68
Jul 16 14:28:29 nuc kernel: [ 370.644298] Call Trace:
Jul 16 14:28:29 nuc kernel: [ 370.644311] [<ffffffff81243ea1>]
alloc_buffer_head+0x21/0x60
Jul 16 14:28:29 nuc kernel: [ 370.644329] [<ffffffff81244379>]
alloc_page_buffers+0x79/0xe0
Jul 16 14:28:29 nuc kernel: [ 370.644349] [<ffffffff812443fe>]
create_empty_buffers+0x1e/0xc0
Jul 16 14:28:29 nuc kernel: [ 370.644369] [<ffffffff812987fc>]
ext4_block_write_begin+0x3cc/0x4e0
Jul 16 14:28:29 nuc kernel: [ 370.644390] [<ffffffff812e8afb>] ?
jbd2__journal_start+0xdb/0x1e0
Jul 16 14:28:29 nuc kernel: [ 370.644410] [<ffffffff81297c40>] ?
ext4_inode_attach_jinode.part.60+0xb0/0xb0
Jul 16 14:28:29 nuc kernel: [ 370.644434] [<ffffffff812ccc2d>] ?
__ext4_journal_start_sb+0x6d/0x120
Jul 16 14:28:29 nuc kernel: [ 370.644456] [<ffffffff8129e61d>]
ext4_da_write_begin+0x15d/0x340
Jul 16 14:28:29 nuc kernel: [ 370.644477] [<ffffffff8118db4e>]
generic_perform_write+0xce/0x1c0
Jul 16 14:28:29 nuc kernel: [ 370.644498] [<ffffffff8118f9f2>]
__generic_file_write_iter+0x1a2/0x1e0
Jul 16 14:28:29 nuc kernel: [ 370.644518] [<ffffffff81292d72>]
ext4_file_write_iter+0x102/0x470
Jul 16 14:28:29 nuc kernel: [ 370.644540] [<ffffffff81403f37>] ?
iov_iter_zero+0x67/0x200
Jul 16 14:28:29 nuc kernel: [ 370.644560] [<ffffffff8120c94b>]
new_sync_write+0x9b/0xe0
Jul 16 14:28:29 nuc kernel: [ 370.644578] [<ffffffff8120c9b6>]
__vfs_write+0x26/0x40
Jul 16 14:28:29 nuc kernel: [ 370.645377] [<ffffffff8120d339>]
vfs_write+0xa9/0x1a0
Jul 16 14:28:29 nuc kernel: [ 370.646174] [<ffffffff8120d274>] ?
vfs_read+0x114/0x130
Jul 16 14:28:29 nuc kernel: [ 370.646973] [<ffffffff8120dff5>]
SyS_write+0x55/0xc0
Jul 16 14:28:29 nuc kernel: [ 370.647766] [<ffffffff8182db32>]
entry_SYSCALL_64_fastpath+0x16/0x71
Jul 16 14:28:29 nuc kernel: [ 370.648547] Code: 08 65 4c 03 05 23 e8 e1
7e 49 83 78 10 00 4d 8b 08 0f 84 29 01 00 00 4d 85 c9 0f 84 20 01 00 00
49 63 47 20 48 8d 4a 01 49 8b 3f <49> 8b 1c 01 4c 89 c8 65 48 0f c7 0f
0f 94 c0 84 c0 74 bb 49 63
Jul 16 14:28:29 nuc kernel: [ 370.650215] RIP [<ffffffff811eb987>]
kmem_cache_alloc+0x77/0x1f0
Jul 16 14:28:29 nuc kernel: [ 370.650985] RSP <ffff880407b9ba80>
Jul 16 14:28:29 nuc kernel: [ 370.651755] ---[ end trace
639091250fabe2af ]---
Shows also a stacktrace with the same call path, also running on a
(different) Intel NUC, also running a 4.4.0 kernel. This pastebin is
nowhere referenced however, so I'm unsure who found it and where exactly
it was posted. Since the offending process in the unknown guy or girl's
pastebin was dd, however, I believe that he or she tried to deliberately
reproduce the problem.
The problem occurs only when the system is under heavy disk load for me
(usually after an hour of activity). I've a process running which
frequently does sqlite3 commits about every 10 seconds. Having it run
overnight with almost no load led to no oooops.
Any and all advice is greatly appreciated.
Cheers,
Johannes
On Mon, Oct 03, 2016 at 12:52:20PM +0200, Johannes Bauer wrote:
> Shows also a stacktrace with the same call path, also running on a
> (different) Intel NUC, also running a 4.4.0 kernel. This pastebin is
> nowhere referenced however, so I'm unsure who found it and where exactly
> it was posted. Since the offending process in the unknown guy or girl's
> pastebin was dd, however, I believe that he or she tried to deliberately
> reproduce the problem.
Have you tried using a 4.4.23 kernel? There are a large number of bug
fixes in the kernel betweeb 4.4.0 and 4.4.23.
The last time I've done a stable kernel test run was against 4.4.17,
and it passed clean:
FSTESTIMG: gce-xfstests/xfstests-201608132226
FSTESTVER: e2fsprogs v1.43.1-22-g25c4a20 (Wed, 8 Jun 2016 18:11:27 -0400)
FSTESTVER: fio fio-2.6-8-ge6989e1 (Thu, 4 Feb 2016 12:09:48 -0700)
FSTESTVER: quota 81aca5c (Tue, 12 Jul 2016 16:15:45 +0200)
FSTESTVER: xfsprogs v4.5.0 (Tue, 15 Mar 2016 15:25:56 +1100)
FSTESTVER: xfstests-bld 75f1eb0 (Sat, 13 Aug 2016 22:18:57 -0400)
FSTESTVER: xfstests linux-v3.8-1149-g4e58a5b (Mon, 8 Aug 2016 10:50:34 -0400)
FSTESTVER: kernel 4.4.17 #4 SMP Mon Aug 15 23:55:25 EDT 2016 x86_64
FSTESTCFG: "all"
FSTESTSET: "-g auto"
FSTESTEXC: "ext4/022"
FSTESTOPT: "aex"
MNTOPTS: ""
CPUS: "2"
MEM: "7477.49"
MEM: 7680 MB (Max capacity)
BEGIN TEST 4k: Ext4 4k block Tue Aug 16 00:05:28 EDT 2016
Passed all 224 tests
- Ted
P.S. Fixes between 4.4.0 and 4.4.17:
% git log --oneline v4.4..v4.4.17 -- fs/ext4 fs/jbd2
26015f0 ext4: verify extent header depth
8b8de1c ext4: silence UBSAN in ext4_mb_init()
12aa7d9 ext4: address UBSAN warning in mb_find_order_for_block()
b2601bb ext4: fix oops on corrupted filesystem
b2044c3 ext4: clean up error handling when orphan list is corrupted
c5ce389 ext4: fix hang when processing corrupted orphaned inode list
fa5613b ext4: iterate over buffer heads correctly in move_extent_per_page()
2122834 ext4: fix races of writeback with punch hole and zero range
1f7b7e9 ext4: fix races between buffered IO and collapse / insert range
e096ade ext4: move unlocked dio protection from ext4_alloc_file_blocks()
0b680de ext4: fix races between page faults and hole punching
c745297 ext4: fix NULL pointer dereference in ext4_mark_inode_dirty()
ee8516a ext4: ignore quota mount options if the quota feature is enabled
321299a ext4: add lockdep annotations for i_data_sem
93272be jbd2: fix FS corruption possibility in jbd2_journal_destroy() on umount path
7c3d142 ext4: fix bh->b_state corruption
bbfe21c ext4: don't read blocks from disk after extents being swapped
600d41f ext4: fix potential integer overflow
33f48f8 ext4: fix scheduling in atomic on group checksum failure
b80b70e ext4 crypto: add missing locking for keyring_key access
Fixes between 4.4.17 and 4.4.23:
% git log --oneline v4.4.17..v4.4.23 -- fs/ext4 fs/jbd2
bf63b9d fscrypto: require write access to mount to set encryption policy
8d693a2 fscrypto: add authorization check for setting encryption policy
d8aafd0 ext4: use __GFP_NOFAIL in ext4_free_blocks()
1d12bad ext4: avoid modifying checksum fields directly during checksum verification
77ae14d ext4: avoid deadlock when expanding inode size
a79f1f7 ext4: properly align shifted xattrs when expanding inodes
e6abdbf ext4: fix xattr shifting when expanding inodes part 2
f2c06c7 ext4: fix xattr shifting when expanding inodes
dfa0a22 ext4: validate that metadata blocks do not overlap superblock
564e0f8 jbd2: make journal y2038 safe
3a22cf0 ext4: fix reference counting bug on block allocation error
db82c74 ext4: short-cut orphan cleanup on error
f8d4d52 ext4: validate s_reserved_gdt_blocks on mount
175f36c ext4: don't call ext4_should_journal_data() on the journal inode
5a7f477 ext4: fix deadlock during page writeback
9e38db2 ext4: check for extents that wrap around
And note that not all fixes get backported. Sometimes a patch is too
large or too complex to backport. Or sometimes we forget to tag a
patch for a stable kernel backport that really should have been
backported. So trying to see if you can replicate the problem using
the latest 4.8 kernel would also be a good thing to try.
Finally, the oops was inside the memory allocator, so it's possible
the problem was caused by a corrupted freelist, which could have been
caused by a wild pointer dereference in any part of the kernel, not
necessarily ext4. Which is another reason to go to the latest 4.4.x
kernel or to try the 4.8 kernel. The bug in some other part of the
subsystem may have since been fixed.
Hi!
On Mon 03-10-16 12:52:20, Johannes Bauer wrote:
> I have recently bought an Intel NUC6i3SYB. That's essentially a small
> form-factor x86_64 PC. That device runs Linux Mint. Unfortunately I see
> frequent kernel oopses within the ext4 subsystem and consequently loss
> of data, corrupted files and complete system crashes. Here's a recent
> call trace:
The problem looks like memory corruption:
> [ 3405.666456] general protection fault: 0000 [#1] SMP
<snip>
> [ 3405.667929] CPU: 3 PID: 2261 Comm: hexchat Not tainted
> 4.4.0-21-generic #37-Ubuntu
> [ 3405.667998] Hardware name: /NUC6i3SYB, BIOS
> SYSKLi35.86A.0042.2016.0409.1246 04/09/2016
> [ 3405.668082] task: ffff88003565ac40 ti: ffff8804332e8000 task.ti:
> ffff8804332e8000
> [ 3405.668148] RIP: 0010:[<ffffffff811eb027>] [<ffffffff811eb027>]
> kmem_cache_alloc+0x77/0x1f0
So we crash in kmem_cache_alloc(), looking at the disassebly at:
mov (%r9,%rax,1),%rbx
Now look at register contents:
> [ 3405.668234] RSP: 0018:ffff8804332eba88 EFLAGS: 00010282
> [ 3405.668282] RAX: 0000000000000000 RBX: 0000000002408040 RCX:
> 00000000000e1547
> [ 3405.668345] RDX: 00000000000e1546 RSI: 0000000002408040 RDI:
> 000000000001a940
> [ 3405.668408] RBP: ffff8804332ebab8 R08: ffff88046ed9a940 R09:
> ffdb88033bb3a3a8
So %rax is 0, %r9 is ffdb88033bb3a3a8 - that's a problem because this is
not a valid kernel pointer. Well, actually it is but it points somewhere to
a vmalloc area and that particular place is apparently unmapped. I don't
think anything in that path should be doing anything with vmalloc so I'd
rather think that something corrupted the pointer. Hum, and looking into
the oops you pasted below, there %r9 is ddff88007f5aff08 - that's
definitely a corrupted pointer.
Anyway, adding linux-mm to CC since this does not look ext4 related but
rather mm related issue.
Bugs like these are always hard to catch, usually it's some flaky device
driver, sometimes also flaky HW. You can try running kernel with various
debug options enabled in a hope to catch the code corrupting memory
earlier - e.g. CONFIG_DEBUG_PAGE_ALLOC sometimes catches something,
CONFIG_SLAB_DEBUG can be useful as well. Another option is to get a
crashdump when the oops happens (although that's going to be a pain to
setup on such a small machine) and then look at which places point to
the corrupted memory - sometimes you can find old structures pointing to
the place and find the use-after-free issue or stuff like that...
Honza
> [ 3405.668470] R10: ffff8804591a4ed0 R11: ffffffff81ccc462 R12:
> 0000000002408040
> [ 3405.668533] R13: ffffffff81243351 R14: ffff88045e08bc00 R15:
> ffff88045e08bc00
> [ 3405.668597] FS: 00007f1df9704a40(0000) GS:ffff88046ed80000(0000)
> knlGS:0000000000000000
> [ 3405.668668] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 3405.668719] CR2: 00007fd945ecebd6 CR3: 0000000456a48000 CR4:
> 00000000003406e0
> [ 3405.668782] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> 0000000000000000
> [ 3405.668844] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
> 0000000000000400
> [ 3405.668906] Stack:
> [ 3405.668926] 01ff880438ee2508 0000000000001000 ffff8803344df000
> ffffea000cd137c0
> [ 3405.669003] 0000000000000000 0000000000000000 ffff8804332ebad0
> ffffffff81243351
> [ 3405.669080] ffff8800354bd024 ffff8804332ebb18 ffffffff81243829
> 00000001332ebb70
> [ 3405.669156] Call Trace:
> [ 3405.669186] [<ffffffff81243351>] alloc_buffer_head+0x21/0x60
> [ 3405.669240] [<ffffffff81243829>] alloc_page_buffers+0x79/0xe0
> [ 3405.669294] [<ffffffff812438ae>] create_empty_buffers+0x1e/0xc0
> [ 3405.669351] [<ffffffff812979cc>] ext4_block_write_begin+0x3cc/0x4d0
> [ 3405.669410] [<ffffffff812e74db>] ? jbd2__journal_start+0xdb/0x1e0
> [ 3405.669469] [<ffffffff81296e10>] ?
> ext4_inode_attach_jinode.part.60+0xb0/0xb0
> [ 3405.669536] [<ffffffff812cb83d>] ? __ext4_journal_start_sb+0x6d/0x120
> [ 3405.669596] [<ffffffff8129d574>] ext4_da_write_begin+0x154/0x320
> [ 3405.669656] [<ffffffff8118d4de>] generic_perform_write+0xce/0x1c0
> [ 3405.669713] [<ffffffff8118f382>] __generic_file_write_iter+0x1a2/0x1e0
> [ 3405.669773] [<ffffffff81291ffc>] ext4_file_write_iter+0xfc/0x460
> [ 3405.669833] [<ffffffff81794d6e>] ? inet_recvmsg+0x7e/0xb0
> [ 3405.669885] [<ffffffff816fdb6b>] ? sock_recvmsg+0x3b/0x50
> [ 3405.669938] [<ffffffff8120bedb>] new_sync_write+0x9b/0xe0
> [ 3405.669990] [<ffffffff8120bf46>] __vfs_write+0x26/0x40
> [ 3405.670040] [<ffffffff8120c8c9>] vfs_write+0xa9/0x1a0
> [ 3405.672397] [<ffffffff8120c776>] ? vfs_read+0x86/0x130
> [ 3405.674693] [<ffffffff8120d585>] SyS_write+0x55/0xc0
> [ 3405.676925] [<ffffffff818244f2>] entry_SYSCALL_64_fastpath+0x16/0x71
> [ 3405.679111] Code: 08 65 4c 03 05 83 f1 e1 7e 49 83 78 10 00 4d 8b 08
> 0f 84 29 01 00 00 4d 85 c9 0f 84 20 01 00 00 49 63 47 20 48 8d 4a 01 49
> 8b 3f <49> 8b 1c 01 4c 89 c8 65 48 0f c7 0f 0f 94 c0 84 c0 74 bb 49 63
> [ 3405.683725] RIP [<ffffffff811eb027>] kmem_cache_alloc+0x77/0x1f0
> [ 3405.685876] RSP <ffff8804332eba88>
> [ 3405.696001] ---[ end trace 4968a9119e168c92 ]---
>
> After this occurs, the system becomes extremely unstable, i.e., the
> filesystem cannot be read properly anymore (e.g., ssh logins usually do
> not work anymore, most binaries just segfault). After a reboot (which
> has to be done manually, "shutdown -r now" also segfaults) it works fine
> again (until the problem comes back).
>
> Since the hardware is fairly new, I cannot exclude a hardware defect as
> of now. I've thouroughly tested the RAM though and not found any defect
> there (ran MemTest86+ for 24 hours). One curious thing is that someone
> else seems to have run into this before. Searching for the symbols in
> the stackframe I came upon this:
>
> http://pastebin.com/BJbu35H4
>
> Which, quoting in full:
>
> Jul 16 14:28:29 nuc kernel: [ 370.642612] general protection fault:
> 0000 [#1] SMP
> Jul 16 14:28:29 nuc kernel: [ 370.642657] Modules linked in: arc4
> intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel
> iwlmvm kvm mac80211 irqbypass crct10dif_pclmul crc32_pclmul iwlwifi
> aesni_intel aes_x86_64 snd_hda_codec_hdmi btusb btrtl
> snd_hda_codec_realtek btbcm btintel lrw gf128mul snd_hda_codec_generic
> ir_xmp_decoder glue_helper ablk_helper ir_lirc_codec cryptd mei_me
> lirc_dev ir_mce_kbd_decoder ir_sharp_decoder ir_sanyo_decoder bluetooth
> cfg80211 snd_hda_intel ir_sony_decoder mei ir_jvc_decoder ir_rc6_decoder
> ir_rc5_decoder ir_nec_decoder lpc_ich snd_hda_codec shpchp
> snd_soc_rt5640 snd_hda_core snd_soc_rl6231 snd_hwdep snd_soc_core
> snd_compress ac97_bus snd_pcm_dmaengine rc_rc6_mce dw_dmac snd_pcm
> nuvoton_cir rc_core snd_timer dw_dmac_core snd elan_i2c soundcore
> snd_soc_sst_acpi spi_pxa2xx_platform i2c_designware_platform
> i2c_designware_core 8250_dw mac_hid ip6t_REJECT nf_reject_ipv6
> nf_log_ipv6 xt_hl ip6t_rt nf_conntrack_ipv6 nf_defrag_ipv6 ipt_REJECT
> nf_reject_ipv4 xt_comment nf_log_ipv4 nf_log_common xt_LOG xt_multiport
> xt_limit xt_tcpudp xt_addrtype nf_conntrack_ipv4 nf_defrag_ipv4
> xt_conntrack ip6table_filter ip6_tables nf_conntrack_netbios_ns
> nf_conntrack_broadcast nf_nat_ftp nf_nat sunrpc nf_conntrack_ftp
> nf_conntrack iptable_filter ip_tables x_tables autofs4 btrfs xor
> raid6_pq i915 i2c_algo_bit drm_kms_helper e1000e syscopyarea sysfillrect
> sysimgblt uas fb_sys_fops ptp ahci sdhci_acpi usb_storage libahci drm
> pps_core video i2c_hid sdhci hid fjes
> Jul 16 14:28:29 nuc kernel: [ 370.643778] CPU: 3 PID: 1505 Comm: dd Not
> tainted 4.4.0-31-generic #50-Ubuntu
> Jul 16 14:28:29 nuc kernel: [ 370.643822] Hardware name:
> /D54250WYK, BIOS WYLPT10H.86A.0041.2015.0720.1108 07/20/2015
> Jul 16 14:28:29 nuc kernel: [ 370.643878] task: ffff88040aa90000 ti:
> ffff880407b98000 task.ti: ffff880407b98000
> Jul 16 14:28:29 nuc kernel: [ 370.643923] RIP:
> 0010:[<ffffffff811eb987>] [<ffffffff811eb987>] kmem_cache_alloc+0x77/0x1f0
> Jul 16 14:28:29 nuc kernel: [ 370.643982] RSP: 0018:ffff880407b9ba80
> EFLAGS: 00010282
> Jul 16 14:28:29 nuc kernel: [ 370.644015] RAX: 0000000000000000 RBX:
> 0000000002408040 RCX: 00000000000bb283
> Jul 16 14:28:29 nuc kernel: [ 370.644054] RDX: 00000000000bb282 RSI:
> 0000000002408040 RDI: 000000000001a940
> Jul 16 14:28:29 nuc kernel: [ 370.644076] RBP: ffff880407b9bab0 R08:
> ffff88041fb9a940 R09: ddff88007f5aff08
> Jul 16 14:28:29 nuc kernel: [ 370.644097] R10: ffff8800d522d060 R11:
> ffffffff81ccf1ea R12: 0000000002408040
> Jul 16 14:28:29 nuc kernel: [ 370.644119] R13: ffffffff81243ea1 R14:
> ffff88040f08bc00 R15: ffff88040f08bc00
> Jul 16 14:28:29 nuc kernel: [ 370.644141] FS: 00007fa227587700(0000)
> GS:ffff88041fb80000(0000) knlGS:0000000000000000
> Jul 16 14:28:29 nuc kernel: [ 370.644165] CS: 0010 DS: 0000 ES: 0000
> CR0: 0000000080050033
> Jul 16 14:28:29 nuc kernel: [ 370.644183] CR2: 0000000000a08000 CR3:
> 000000040aaac000 CR4: 00000000001406e0
> Jul 16 14:28:29 nuc kernel: [ 370.644205] Stack:
> Jul 16 14:28:29 nuc kernel: [ 370.644213] 01ff8803fef10a00
> 0000000000001000 ffff88007b89f000 ffffea0001ee27c0
> Jul 16 14:28:29 nuc kernel: [ 370.644241] 0000000000000000
> 0000000000000000 ffff880407b9bac8 ffffffff81243ea1
> Jul 16 14:28:29 nuc kernel: [ 370.644270] ffff8804099b8024
> ffff880407b9bb10 ffffffff81244379 0000000107b9bb68
> Jul 16 14:28:29 nuc kernel: [ 370.644298] Call Trace:
> Jul 16 14:28:29 nuc kernel: [ 370.644311] [<ffffffff81243ea1>]
> alloc_buffer_head+0x21/0x60
> Jul 16 14:28:29 nuc kernel: [ 370.644329] [<ffffffff81244379>]
> alloc_page_buffers+0x79/0xe0
> Jul 16 14:28:29 nuc kernel: [ 370.644349] [<ffffffff812443fe>]
> create_empty_buffers+0x1e/0xc0
> Jul 16 14:28:29 nuc kernel: [ 370.644369] [<ffffffff812987fc>]
> ext4_block_write_begin+0x3cc/0x4e0
> Jul 16 14:28:29 nuc kernel: [ 370.644390] [<ffffffff812e8afb>] ?
> jbd2__journal_start+0xdb/0x1e0
> Jul 16 14:28:29 nuc kernel: [ 370.644410] [<ffffffff81297c40>] ?
> ext4_inode_attach_jinode.part.60+0xb0/0xb0
> Jul 16 14:28:29 nuc kernel: [ 370.644434] [<ffffffff812ccc2d>] ?
> __ext4_journal_start_sb+0x6d/0x120
> Jul 16 14:28:29 nuc kernel: [ 370.644456] [<ffffffff8129e61d>]
> ext4_da_write_begin+0x15d/0x340
> Jul 16 14:28:29 nuc kernel: [ 370.644477] [<ffffffff8118db4e>]
> generic_perform_write+0xce/0x1c0
> Jul 16 14:28:29 nuc kernel: [ 370.644498] [<ffffffff8118f9f2>]
> __generic_file_write_iter+0x1a2/0x1e0
> Jul 16 14:28:29 nuc kernel: [ 370.644518] [<ffffffff81292d72>]
> ext4_file_write_iter+0x102/0x470
> Jul 16 14:28:29 nuc kernel: [ 370.644540] [<ffffffff81403f37>] ?
> iov_iter_zero+0x67/0x200
> Jul 16 14:28:29 nuc kernel: [ 370.644560] [<ffffffff8120c94b>]
> new_sync_write+0x9b/0xe0
> Jul 16 14:28:29 nuc kernel: [ 370.644578] [<ffffffff8120c9b6>]
> __vfs_write+0x26/0x40
> Jul 16 14:28:29 nuc kernel: [ 370.645377] [<ffffffff8120d339>]
> vfs_write+0xa9/0x1a0
> Jul 16 14:28:29 nuc kernel: [ 370.646174] [<ffffffff8120d274>] ?
> vfs_read+0x114/0x130
> Jul 16 14:28:29 nuc kernel: [ 370.646973] [<ffffffff8120dff5>]
> SyS_write+0x55/0xc0
> Jul 16 14:28:29 nuc kernel: [ 370.647766] [<ffffffff8182db32>]
> entry_SYSCALL_64_fastpath+0x16/0x71
> Jul 16 14:28:29 nuc kernel: [ 370.648547] Code: 08 65 4c 03 05 23 e8 e1
> 7e 49 83 78 10 00 4d 8b 08 0f 84 29 01 00 00 4d 85 c9 0f 84 20 01 00 00
> 49 63 47 20 48 8d 4a 01 49 8b 3f <49> 8b 1c 01 4c 89 c8 65 48 0f c7 0f
> 0f 94 c0 84 c0 74 bb 49 63
> Jul 16 14:28:29 nuc kernel: [ 370.650215] RIP [<ffffffff811eb987>]
> kmem_cache_alloc+0x77/0x1f0
> Jul 16 14:28:29 nuc kernel: [ 370.650985] RSP <ffff880407b9ba80>
> Jul 16 14:28:29 nuc kernel: [ 370.651755] ---[ end trace
> 639091250fabe2af ]---
>
> Shows also a stacktrace with the same call path, also running on a
> (different) Intel NUC, also running a 4.4.0 kernel. This pastebin is
> nowhere referenced however, so I'm unsure who found it and where exactly
> it was posted. Since the offending process in the unknown guy or girl's
> pastebin was dd, however, I believe that he or she tried to deliberately
> reproduce the problem.
>
> The problem occurs only when the system is under heavy disk load for me
> (usually after an hour of activity). I've a process running which
> frequently does sqlite3 commits about every 10 seconds. Having it run
> overnight with almost no load led to no oooops.
>
> Any and all advice is greatly appreciated.
> Cheers,
> Johannes
> --
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--
Jan Kara <[email protected]>
SUSE Labs, CR
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On 04.10.2016 10:41, Jan Kara wrote:
> The problem looks like memory corruption:
[...]
Huh, very interesting -- thanks for the walkthrough!
> Anyway, adding linux-mm to CC since this does not look ext4 related but
> rather mm related issue.
>
> Bugs like these are always hard to catch, usually it's some flaky device
> driver, sometimes also flaky HW. You can try running kernel with various
> debug options enabled in a hope to catch the code corrupting memory
> earlier - e.g. CONFIG_DEBUG_PAGE_ALLOC sometimes catches something,
> CONFIG_SLAB_DEBUG can be useful as well. Another option is to get a
> crashdump when the oops happens (although that's going to be a pain to
> setup on such a small machine) and then look at which places point to
> the corrupted memory - sometimes you can find old structures pointing to
> the place and find the use-after-free issue or stuff like that...
Uhh, that sounds painful. So I'm following Ted's advice and building
myself a 4.8 as we speak.
If the problem is fixed, would it be of any help to trace the source by
going back to the 4.4.0 and reproduce with the debug symbols you
mentioned? I don't think a memdump would be difficult on the machine
(while it certainly has a small form factor, it's got a 1 TB hdd and 16
GB of RAM, so it's not really that small).
Cheers,
Johannes
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On 04.10.2016 18:50, Johannes Bauer wrote:
> Uhh, that sounds painful. So I'm following Ted's advice and building
> myself a 4.8 as we speak.
Damn bad idea to build on the instable target. Lots of gcc segfaults and
weird stuff, even without a kernel panic. The system appears to be
instable as hell. Wonder how it can even run and how much of the root fs
is already corrupted :-(
Rebuilding 4.8 on a different host.
Cheers,
Johannes
On Tue, Oct 4, 2016 at 8:32 PM, Johannes Bauer <[email protected]> wrote:
> On 04.10.2016 18:50, Johannes Bauer wrote:
>
>> Uhh, that sounds painful. So I'm following Ted's advice and building
>> myself a 4.8 as we speak.
>
> Damn bad idea to build on the instable target. Lots of gcc segfaults and
> weird stuff, even without a kernel panic. The system appears to be
> instable as hell. Wonder how it can even run and how much of the root fs
> is already corrupted :-(
>
> Rebuilding 4.8 on a different host.
Looks like a platform itself is somewhat faulty: [1]. Also please bear
in mind that standalone memory testers would rather not expose certain
classes of memory failures, I`d suggest to test allocator`s work
against gcc runs on tmpfs, almost same as you did before. Frequency of
crashes due to wrong pointer contents of an fs cache is most probably
a direct outcome from its relative memory footprint.
1. https://communities.intel.com/thread/105640
On 04.10.2016 20:45, Andrey Korolyov wrote:
> On Tue, Oct 4, 2016 at 8:32 PM, Johannes Bauer <[email protected]> wrote:
>> On 04.10.2016 18:50, Johannes Bauer wrote:
>>
>>> Uhh, that sounds painful. So I'm following Ted's advice and building
>>> myself a 4.8 as we speak.
>>
>> Damn bad idea to build on the instable target. Lots of gcc segfaults and
>> weird stuff, even without a kernel panic. The system appears to be
>> instable as hell. Wonder how it can even run and how much of the root fs
>> is already corrupted :-(
>>
>> Rebuilding 4.8 on a different host.
>
> Looks like a platform itself is somewhat faulty: [1].
Thanks for the hint, I'll post there as well. The device is less than 4
weeks old, so it's still under full warranty. Maybe it really is the HW
and I'll return it.
> Also please bear
> in mind that standalone memory testers would rather not expose certain
> classes of memory failures, I`d suggest to test allocator`s work
> against gcc runs on tmpfs, almost same as you did before. Frequency of
> crashes due to wrong pointer contents of an fs cache is most probably
> a direct outcome from its relative memory footprint.
I will and did, but strangely some kernel building on /dev/shm worked
really nice. I Ctrl-Ced, rebooted for good measure and rsynced the 4.8.0
on the device. Then, I tried to update-initramfs:
nuc [/lib/modules]: update-initramfs -u
update-initramfs: Generating /boot/initrd.img-4.4.0-21-generic
modinfo: ERROR: could not get modinfo from 'qla3xxx': Invalid argument
Segmentation fault
Segmentation fault
modinfo: ERROR: could not get modinfo from 'mpt3sas': Invalid argument
modinfo: ERROR: could not get modinfo from 'pktcdvd': No such file or
directory
Bus error
Bus error
Bus error
Bus error
Bus error
Bus error
Bus error
Bus error
Bus error
Bus error
Bus error
Bus error
[...]
Segmentation fault
Segmentation fault
Segmentation fault
Segmentation fault
update-initramfs: failed for /boot/initrd.img-4.4.0-21-generic with 139.
update-initramfs causes heavy disk I/O, so really maybe it's something
with the disk driver. As of now I really can't get 4.8.0 to even get to
a point where it'd be bootable.
I'll continue fighting on all fronts and report as soon as I learn more.
Thanks for the help, it is very much appreciated.
Cheers,
Joe
On 04.10.2016 20:45, Andrey Korolyov wrote:
>> Damn bad idea to build on the instable target. Lots of gcc segfaults and
>> weird stuff, even without a kernel panic. The system appears to be
>> instable as hell. Wonder how it can even run and how much of the root fs
>> is already corrupted :-(
>>
>> Rebuilding 4.8 on a different host.
>
> Looks like a platform itself is somewhat faulty: [1]. Also please bear
> in mind that standalone memory testers would rather not expose certain
> classes of memory failures, I`d suggest to test allocator`s work
> against gcc runs on tmpfs, almost same as you did before. Frequency of
> crashes due to wrong pointer contents of an fs cache is most probably
> a direct outcome from its relative memory footprint.
So there's some interesting new data points that I couldn't make sense
of. Maybe you can.
First off, 4.8.0 shows the same symptoms. When I try to build 4.8.0 in
/usr/src/linux using make -j4, I get bus errors and segfaults in gcc
pretty soon.
Doing the same thing in /dev/shm, however, builds like a charm. Three
kernels built, all ran through perfectly. Not one try in /usr/src did
that, all my attempts failed.
What could cause this? Faulty hard drive? It's brand new:
Model Family: Western Digital Red
Device Model: WDC WD10JFCX-68N6GN0
Firmware Version: 82.00A82
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE
UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always
- 0
3 Spin_Up_Time 0x0027 182 181 021 Pre-fail Always
- 1858
4 Start_Stop_Count 0x0032 100 100 000 Old_age Always
- 17
5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always
- 0
7 Seek_Error_Rate 0x002e 200 200 000 Old_age Always
- 0
9 Power_On_Hours 0x0032 100 100 000 Old_age Always
- 178
Or faulty AHCI controller or driver?
[ 9.746277] ahci 0000:00:17.0: version 3.0
[ 9.746499] ahci 0000:00:17.0: AHCI 0001.0301 32 slots 1 ports 6 Gbps
0x1 impl SATA mode
[ 9.746501] ahci 0000:00:17.0: flags: 64bit ncq pm led clo only pio
slum part deso sadm sds apst
[ 9.753844] scsi host0: ahci
[ 9.754648] ata1: SATA max UDMA/133 abar m2048@0xdf14d000 port
0xdf14d100 irq 275
I'm super puzzled right now :-(
Cheers,
Johannes
> I'm super puzzled right now :-(
>
There are three strawman` ideas out of head, down by a level of
naiveness increase:
- disk controller corrupts DMA chunks themselves, could be tested
against usb stick/sd card with same fs or by switching disk controller
to a legacy mode if possible, but cascading failure shown previously
should be rather unusual for this,
- SMP could be partially broken in such manner that it would cause
overlapped accesses under certain conditions, may be checked with
'nosmp',
- disk accesses and corresponding power spikes are causing partial
undervoltage condition somewhere where bits are relatively freely
flipping on paths without parity checking, though this could be
addressed only to an onboard power distributor, not to power source
itself.
On 04.10.2016 20:45, Andrey Korolyov wrote:
> 1. https://communities.intel.com/thread/105640
Created a thread in the Intel forum, here's for cross reference:
https://communities.intel.com/message/425731
Cheers,
Johannes
On 04.10.2016 22:17, Andrey Korolyov wrote:
>> I'm super puzzled right now :-(
>>
>
> There are three strawman` ideas out of head, down by a level of
> naiveness increase:
> - disk controller corrupts DMA chunks themselves, could be tested
> against usb stick/sd card with same fs or by switching disk controller
> to a legacy mode if possible, but cascading failure shown previously
> should be rather unusual for this,
I'll check out if this is possible somehow tomorrow.
> - SMP could be partially broken in such manner that it would cause
> overlapped accesses under certain conditions, may be checked with
> 'nosmp',
Unfortunately not:
CC [M] drivers/infiniband/core/multicast.o
CC [M] drivers/infiniband/core/mad.o
drivers/infiniband/core/mad.c: In function ‘ib_mad_port_close’:
drivers/infiniband/core/mad.c:3252:1: internal compiler error: Bus error
}
^
nuc [~]: cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-4.8.0 root=UUID=f6a792b3-3027-4293-a118-f0df1de9b25c
ro ip=:::::eno1:dhcp nosmp
> - disk accesses and corresponding power spikes are causing partial
> undervoltage condition somewhere where bits are relatively freely
> flipping on paths without parity checking, though this could be
> addressed only to an onboard power distributor, not to power source
> itself.
Huh that sounds like "defective hardware" to me, wouldn't it?
Cheers and thank you for your help,
Johannes
On Tue 04-10-16 23:54:24, Johannes Bauer wrote:
> > - disk accesses and corresponding power spikes are causing partial
> > undervoltage condition somewhere where bits are relatively freely
> > flipping on paths without parity checking, though this could be
> > addressed only to an onboard power distributor, not to power source
> > itself.
>
> Huh that sounds like "defective hardware" to me, wouldn't it?
Yeah, from the frequency and the kind of failures, I actually don't think
it's a kernel bug anymore. So I'd also suspect something like that bits on
memory bus start to flip when the disk is loaded or something like that.
If you say compilation on tmpfs is fine - can you try compiling kernel in
tmpfs in a loop and then after it is running smoothly for a while start to
load the disk by copying a lot of data there? Do the errors trigger?
Honza
--
Jan Kara <[email protected]>
SUSE Labs, CR
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