Re: 2.6.8.1-mm4 (strange behavior on dual Opteron w/ NUMA)

[David Howells <dhowells@redhat.com>]

Rafael J. Wysocki <rjw@sisk.pl> wrote:
> It has the same problems that I've reported for 2.6.8.1-mm3:
> 
> 1) ALT-SysRq-<command key> does not work, although "echo <command> > 
> /proc/sysrq-trigger" does (may be specific to x86-64).

I'm seeing this on my Dual PPro testbox too. I'm running 2.6.8.1-mm4 using the
i386 arch. I get an oops (which I've attached) from SysRq+B and from normal
reboot.

> 2) After issuing:
> 
> # rmmod snd_seq_oss
> 
> the kernel goes into a strange state:

And that too; except that I'm seeing it with NFS and modules of my own
devising. I've attached an excerpt of a SysRq trace of this. Note that it
doesn't start executing the module exit function as far as I can tell.

Both these problems are 100% reproducible.

David


===========
REBOOT OOPS
===========

nfsd: last server has exited
nfsd: unexporting all filesystems
Restarting system.
Unable to handle kernel paging request at virtual address c041a3e0
 printing eip:
c041a3e0
*pde = 00463027
*pte = 0041a000
Oops: 0000 [#1]
SMP DEBUG_PAGEALLOC
Modules linked in: nfs cachefs
CPU:    0
EIP:    0060:[<c041a3e0>]    Not tainted VLI
EFLAGS: 00010282   (2.6.8.1-mm4) 
EIP is at find_isa_irq_pin+0x0/0x70
eax: 00000003   ebx: 00000000   ecx: 000100fe   edx: 00000000
esi: 01234567   edi: c4d6c000   ebp: c4d6c000   esp: c4d6de60
ds: 007b   es: 007b   ss: 0068
Process reboot (pid: 2751, threadinfo=c4d6c000 task=c5527a40)
Stack: c011227f 00000000 00000003 00000000 00000001 00000000 c010ebc8 00000000 
       c4d6c000 c010ebe9 01234567 c4d6c000 c011c167 c0351071 00000000 c012ba1d 
       00000000 00000001 00000000 c10bb7c0 00000001 00000000 c01452ef c10bb7c0 
Call Trace:
 [<c011227f>] disable_IO_APIC+0x1f/0x140
 [<c010ebc8>] machine_shutdown+0x48/0x60
 [<c010ebe9>] machine_restart+0x9/0x90
 [<c011c167>] printk+0x17/0x20
 [<c012ba1d>] sys_reboot+0x19d/0x400
 [<c01452ef>] cache_free_debugcheck+0x17f/0x2b0
 [<c02d41fb>] sock_destroy_inode+0x1b/0x20
 [<c02d41fb>] sock_destroy_inode+0x1b/0x20
 [<c017dc65>] destroy_inode+0x35/0x60
 [<c017f67e>] generic_forget_inode+0x14e/0x1c0
 [<c01452ef>] cache_free_debugcheck+0x17f/0x2b0
 [<c017f773>] iput+0x63/0x90
 [<c017abd3>] dput+0x33/0x340
 [<c0160168>] __fput+0xa8/0x110
 [<c0160170>] __fput+0xb0/0x110
 [<c015e5d9>] filp_close+0x59/0x90
 [<c015e68f>] sys_close+0x7f/0x100
 [<c0113ae0>] do_page_fault+0x0/0x5c0
 [<c010459f>] syscall_call+0x7/0xb
Code:  Bad EIP value.
 Badness in send_IPI_mask_bitmask at arch/i386/kernel/smp.c:167
 [<c010f5c4>] send_IPI_mask_bitmask+0x74/0x80
 [<c010f9df>] smp_send_reschedule+0x1f/0x30
 [<c01155b0>] try_to_wake_up+0x2b0/0x2e0
 [<c0117041>] __wake_up_common+0x41/0x70
 [<c01170bb>] __wake_up+0x4b/0xb0
 [<c012e44f>] __queue_work+0x5f/0xc0
 [<c012e505>] queue_work+0x55/0x70
 [<c012e3c9>] call_usermodehelper+0xc9/0xd6
 [<c012e290>] __call_usermodehelper+0x0/0x70
 [<c02565ef>] sprintf+0x1f/0x30
 [<c0253486>] kset_hotplug+0x1f6/0x290
 [<c0253587>] kobject_hotplug+0x67/0x70
 [<c02538fb>] kobject_del+0x1b/0x40
 [<c02875d9>] class_device_del+0x99/0xc0
 [<c0287613>] class_device_unregister+0x13/0x30
 [<c0287c53>] class_simple_device_remove+0xa3/0x127
 [<c026d42c>] vcs_remove_devfs+0x1c/0x39
 [<c0275145>] con_close+0x85/0x90
 [<c0263a1d>] release_dev+0x6ad/0x6d0
 [<c01452a1>] cache_free_debugcheck+0x131/0x2b0
 [<c014f3da>] remove_vm_struct+0x8a/0xd0
 [<c0263f95>] tty_release+0x45/0xc0
 [<c010f829>] flush_tlb_mm+0x49/0xa0
 [<c01601be>] __fput+0xfe/0x110
 [<c015e5d9>] filp_close+0x59/0x90
 [<c011da54>] put_files_struct+0x64/0xd0
 [<c011ea90>] do_exit+0x1f0/0x590
 [<c015f361>] sys_read+0x51/0x80
 [<c011ee63>] sys_exit+0x13/0x20
 [<c010459f>] syscall_call+0x7/0xb


=====================
RMMOD SYSRQ+T EXCERPT
=====================

rmmod         D C0341C03     0  2010   1932                     (NOTLB)
c4737e80 00000082 00000002 c0341c03 c4737ec4 c012e505 c4737e64 0dfec5b1 
       00000007 3e5a438a 00015b43 c41fddb0 15b433e8 00000000 c1104f60 c3c72bec 
       c01150a5 c3d95a40 c11054ac c4737f04 c4737f08 c4737ec0 c4737ee8 c0341c03 
Call Trace:
 [<c0341c03>] wait_for_completion+0xb3/0x1a0
 [<c012e505>] queue_work+0x55/0x70
 [<c01150a5>] activate_task+0xf5/0x120
 [<c0341c03>] wait_for_completion+0xb3/0x1a0
 [<c0116fe0>] default_wake_function+0x0/0x20
 [<c0116fe0>] default_wake_function+0x0/0x20
 [<c01155fd>] wake_up_process+0x1d/0x30
 [<c0139b3c>] __stop_machine_run+0x9c/0xc0
 [<c0138e80>] __try_stop_module+0x0/0x41
 [<c0139b7f>] stop_machine_run+0x1f/0x38
 [<c0138e80>] __try_stop_module+0x0/0x41
 [<c01360d8>] try_stop_module+0x38/0x40
 [<c0138e80>] __try_stop_module+0x0/0x41
 [<c01362a2>] sys_delete_module+0x122/0x180
 [<c01212ea>] __do_softirq+0xba/0xd0
 [<c01103dd>] smp_apic_timer_interrupt+0x8d/0x100
 [<c010456c>] system_call+0x0/0x2c
 [<c010459f>] syscall_call+0x7/0xb
kstopmachine  R running     0  2011      6  2012            36 (L-TLB)
kstopmachine  R running     0  2012   2011                     (L-TLB)