Re: [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm2-V0.7.1

Re: [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm2-V0.7.1

[Mark_H_Johnson]

>there was one place missing - does the patch below fix this type of
>deadlock?

A different deadlock this time, same two actors but apparently a
different pair of locks.

Will send the full console log shortly.
  --Mark


===============================================
BUG: circular semaphore deadlock detected!
-----------------------------------------------
ksoftirqd/1/6 is deadlocking current task ksoftirqd/0/3


1) ksoftirqd/0/3 is trying to acquire this lock:
 [dfb5c8a4] {r:0,a:-1,&n->lock}
.. held by:       ksoftirqd/1/    6 [dff886f0,   0]
... acquired at:  arp_solicit+0x167/0x230
... trying at:   neigh_update+0x2a/0x390

2) ksoftirqd/1/6 is blocked on this lock:
 [c03c8900] {r:1,a:-1,ptype_lock}
.. held by:       ksoftirqd/0/    3 [dffe8020,   0]
... acquired at:  net_rx_action+0x8e/0x200

------------------------------
| showing all locks held by: |  (ksoftirqd/0/3 [dffe8020,   0]):
------------------------------

#001:             [d9044c30] {r:0,a:-1,&tp->rx_lock}
... acquired at:  rtl8139_poll+0x48/0x180 [8139too]

------------------------------
| showing all locks held by: |  (ksoftirqd/1/6 [dff886f0,   0]):
------------------------------

#001:             [dfb5c8a4] {r:0,a:-1,&n->lock}
... acquired at:  arp_solicit+0x167/0x230

Re: [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm2-V0.7.1

[Ingo Molnar]

* Mark_H_Johnson@raytheon.com <Mark_H_Johnson@raytheon.com> wrote:

> 1) ksoftirqd/0/3 is trying to acquire this lock:
>  [dfb5c8a4] {r:0,a:-1,&n->lock}
> .. held by:       ksoftirqd/1/    6 [dff886f0,   0]
> ... acquired at:  arp_solicit+0x167/0x230
> ... trying at:   neigh_update+0x2a/0x390
> 
> 2) ksoftirqd/1/6 is blocked on this lock:
>  [c03c8900] {r:1,a:-1,ptype_lock}
> .. held by:       ksoftirqd/0/    3 [dffe8020,   0]
> ... acquired at:  net_rx_action+0x8e/0x200

this is a weird one. Note how ptype_lock is not shown to be owned by
ksoftirqd/0/3:

> ------------------------------
> | showing all locks held by: |  (ksoftirqd/0/3 [dffe8020,   0]):
> ------------------------------
> 
> #001:             [d9044c30] {r:0,a:-1,&tp->rx_lock}
> ... acquired at:  rtl8139_poll+0x48/0x180 [8139too]

neither does ptype_lock show up in the other logs you sent.

	Ingo

Re: [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm2-V0.7.11 (oops)

[Fernando Pablo Lopez-Lezcano]

I'm getting this on my athlon64 test machine with V0.7.11:

Freeing unused kernel memory: 208k freed
SELinux:  Disabled at runtime.
SELinux:  Unregistering netfilter hooks
IRQ#8 thread RT prio: 44.
ACPI: Power Button (FF) [PWRF]
ACPI: Sleep Button (CM) [SLPB]
ibm_acpi: ec object not found
BUG: Unable to handle kernel paging request at virtual address f888d940
 printing eip:
c0229153
*pde = 37f40067
Oops: 0002 [#1]
PREEMPT 
Modules linked in: video(U) container(U) button(U) battery(U) ac(U)
ext3(U) jbd(U) raid5(U) xor(U) sata_via(U) sata_promise(U) libata(U)
sd_mod(U) scsi_mod(U)
CPU:    0
EIP:    0060:[<c0229153>]    Not tainted VLI
EFLAGS: 00010286   (2.6.9-1.520.1rV0.7.11.ll.rhfc2.ccrma) 
EIP is at acpi_bus_register_driver+0x40/0x63
eax: f888d940   ebx: f88960c0   ecx: c013ef0b   edx: 00000002
esi: 00000000   edi: 00000000   ebp: f68a3f94   esp: f68a3f8c
ds: 007b   es: 007b   ss: 0068   preempt: 00000001
Process insmod (pid: 1012, threadinfo=f68a2000 task=f688a000)
Stack: c03ba660 f8896680 f68a3fa0 f887e039 f88960c0 f68a3fbc c0144ec9
c049a5a4 
       00000001 f8896680 0807a018 00000000 f68a2000 c01072a1 0807a018
00004ad4 
       0807a008 00000000 00000000 bfffced8 00000080 0000007b 0000007b
00000080 
Call Trace:
 [<c010811f>] show_stack+0x8f/0xb0 (28)
 [<c01082da>] show_registers+0x16a/0x1d0 (56)
 [<c01084f1>] die+0xf1/0x190 (64)
 [<c011de39>] do_page_fault+0x369/0x660 (216)
 [<c0107d21>] error_code+0x2d/0x38 (76)
 [<f887e039>] acpi_video_init+0x39/0x59 [video] (12)
 [<c0144ec9>] sys_init_module+0x169/0x220 (28)
 [<c01072a1>] sysenter_past_esp+0x52/0x71 (-8124)
---------------------------
| preempt count: 00000002 ]
| 2-level deep critical section nesting:
----------------------------------------
.. [<c010843e>] .... die+0x3e/0x190
.....[<c011de39>] ..   ( <= do_page_fault+0x369/0x660)
.. [<c0140c9d>] .... print_traces+0x1d/0x60
.....[<c010811f>] ..   ( <= show_stack+0x8f/0xb0)

Code: b8 ed ff ff ff eb 42 85 db b8 ea ff ff ff 74 39 68 60 a6 3b c0 e8
de 5d f1 ff c7 03 1c a7 3b c0 a1 20 a7 3b c0 89 1d 20 a7 3b c0 <89> 18
89 43 04 c7 04 24 60 a6 3b c0 e8 7c 5e f1 ff 58 89 5d 08 
 insmod:1012 BUG: lock held at task exit time!
 [c03ba660] {drivers/acpi/scan.c:27}
.. held by:            insmod/ 1012 [f688a000, 118]
... acquired at:  acpi_bus_register_driver+0x2f/0x63
ACPI: PCI interrupt 0000:00:10.4[C] -> GSI 21 (level, low) -> IRQ 21
ehci_hcd 0000:00:10.4: EHCI Host Controller
ehci_hcd 0000:00:10.4: irq 21, pci mem 0xcfffed00
ehci_hcd 0000:00:10.4: new USB bus registered, assigned bus number 1
ehci_hcd 0000:00:10.4: USB 2.0 enabled, EHCI 1.00, driver 2004-May-10

The machine can boot single user. Kudzu hangs (but I can reboot with
ctrl-alt-del), if I disable kudzu it does not make it to X. Apparently
hangs, cannot reboot of do anything. With "acpi=off" it hangs after
(apparently) loading sata_via, responds to ctrl-alt-del. 

-- Fernando

Re: [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm2-V0.7.11 (oops)

[Ingo Molnar]

* Fernando Pablo Lopez-Lezcano <nando@ccrma.Stanford.EDU> wrote:

> I'm getting this on my athlon64 test machine with V0.7.11:

> EIP is at acpi_bus_register_driver+0x40/0x63

does vanilla 2.6.10-rc1-mm2 boot fine?

	Ingo