2011/4/27 Philippe Gerum r...@xenomai.org:
On Wed, 2011-04-27 at 20:42 +0200, Jean-Michel Hautbois wrote:
Hi list,
I am currently using a Xenomai port on a linux 2.6.35.11 linux kernel
and the adeos-ipipe-2.6.35.7-powerpc-2.12-01.patch.
I am facing a scheduling issue on a P2020 (dual core PowerPC), and I
get the following message :
Badness at arch/powerpc/mm/mmu_context_nohash.c:209
NIP: c0018d20 LR: c039b94c CTR: c00343e4
REGS: ecfadce0 TRAP: 0700 Tainted: G W (2.6.35.11)
MSR: 00021000 ME,CE CR: 24000488 XER:
TASK = ec5220d0[496] 'sipaq' THREAD: ecfac000 CPU: 1
GPR00: 0001 ecfadd90 ec5220d0 ec5df340 ec58a700
0003
GPR08: c04a2d98 0007 c04a2d98 0067e000 0002f385 1007f1f8 c04a5b40
ecfac040
GPR16: c04a5b40 c04deb80 c04a2120 c04a2d98 c04a5b40 c04d008c ecfac000
00029000
GPR24: c04d c04d1e6c 0001 ec58a700 eceaf390 c04d1e78 c0b23b40
ec5df340
NIP [c0018d20] switch_mmu_context+0x80/0x438
LR [c039b94c] schedule+0x774/0x7dc
Call Trace:
[ecfadd90] [44000484] 0x44000484 (unreliable)
[ecfadde0] [c039b94c] schedule+0x774/0x7dc
[ecfade50] [c039cb98] do_nanosleep+0xc8/0x114
[ecfade80] [c0059bf8] hrtimer_nanosleep+0xd8/0x158
[ecfadf10] [c0059d48] sys_nanosleep+0xd0/0xd4
[ecfadf40] [c0013c0c] ret_from_syscall+0x0/0x3c
--- Exception: c01 at 0xffa6cc4
LR = 0xffa6cb0
Instruction dump:
40a2fff0 4c00012c 2f80 409e0128 813b018c 2f83 39290001 913b018c
419e0020 8003018c 7c34 5400d97e 0f00 8123018c 3929 9123018c
Do you have a clue on how to start debugging it ?
Yes, but that can't be easily summarized here. In short, we have a
serious problem with the sharing of the MMU context between the Linux
and Xenomai schedulers in the SMP case on powerpc.
OK, good to know that it is a known issue. If there is a thread with
some thoughts about it, I am interested ;).
It is happening quite randomly... :).
Does disabling CONFIG_XENO_HW_UNLOCKED_SWITCH clear this issue?
Well, yes and no. It starts well, but when booting the kernel I get :
Badness at kernel/lockdep.c:2327
NIP: c006e554 LR: c006e53c CTR: 000186a0
REGS: effe9e00 TRAP: 0700 Not tainted (2.6.35.11)
MSR: 00021000 ME,CE CR: 24242022 XER:
TASK = c0508398[0] 'swapper' THREAD: c052e000 CPU: 0
GPR00: effe9eb0 c0508398 0001 80021000 ea50 0060 0003
GPR08: c0501e80 c053 c051 0001 44242028 100488d8 3ff91200
GPR16: 3ff85950 3ff85950 3ffb1254 c0a446e0 c0a44700 c053 c0a44704
GPR24: c0537084 0010 c0539838 80029000 c001444c c053 c0508398
NIP [c006e554] trace_hardirqs_on_caller+0x148/0x18c
LR [c006e53c] trace_hardirqs_on_caller+0x130/0x18c
Call Trace:
[effe9eb0] [c006e50c] trace_hardirqs_on_caller+0x100/0x18c (unreliable)
[effe9ed0] [c001444c] restore+0x10/0x64
[effe9f90] [0010] 0x10
[effe9fb0] [c001c568] mpic_unmask_irq+0x84/0xb8
[effe9fd0] [c00816f4] handle_fasteoi_irq+0xe4/0x138
[effe9ff0] [c0013628] call_handle_irq+0x18/0x28
[c052fdc0] [c0004fe0] handle_one_irq+0x94/0x100
[c052fde0] [c000b120] __ipipe_do_IRQ+0x78/0xa8
[c052fe10] [c0085234] __ipipe_sync_stage+0x1b0/0x33c
[c052fe50] [c000a404] __ipipe_handle_irq+0x20c/0x260
[c052fe90] [c000a614] __ipipe_grab_irq+0x4c/0x188
[c052fec0] [c0014a60] __ipipe_ret_from_except+0x0/0xc
[c052ff80] [c0009224] cpu_idle+0x64/0xe0
[c052ffa0] [c000234c] rest_init+0xd0/0xe4
[c052ffc0] [c04c9ae0] start_kernel+0x2b0/0x348
[c052fff0] [c3c4] skpinv+0x2dc/0x318
Instruction dump:
2f80 409eff5c 800205d8 2f80 419eff50 481b8281 2f83 41beff00
3d20c053 8009732c 2f80 40befef0 0fe0 4bfffee8 7fe3fb78 3881
And after starting my applications, it gets really bad :
Badness at arch/powerpc/mm/mmu_context_nohash.c:209
NIP: c0017958 LR: c039f560 CTR: c00347f8
REGS: ed38bdd0 TRAP: 0700 Tainted: G W (2.6.35.11)
MSR: 00021000 ME,CE CR: 24000828 XER:
TASK = ecb2c260[405] 'ethctl' THREAD: ed38a000 CPU: 1
GPR00: 0001 ed38be80 ecb2c260 ec70f200 ec89a200 0025 c161ccc0 0003
GPR08: ec7fb000 0001 ec89a3c0 c052 0002a106 101110d0 c04e9cc0 c04e9cc0
GPR16: c04e9cc0 c04e9cc0 c04e92e0 c04e9cc0 ed38a000 c051b084 c051b084 c04e9cc0
GPR24: ecb2c4d0 c0519b2c 0001 c04e92e0 c161ccc0 ecb2c260 ec89a200 ec70f200
NIP [c0017958] switch_mmu_context+0x54/0x3d8
LR [c039f560] schedule+0x780/0x824
Call Trace:
[ed38be80] [24000822] 0x24000822 (unreliable)
[ed38bed0] [c039f560] schedule+0x780/0x824
[ed38bf40] [c00133c0] recheck+0x0/0x24
Instruction dump:
7f49b02e 7ca6 54008ffe 0f00 812401c8 2f83 39290001 912401c8
419e0020 800301c8 7c34 5400d97e 0f00 812301c8 3929 912301c8
[ cut here ]
Badness at arch/powerpc/mm/mmu_context_nohash.c:209
NIP: c0017958 LR: c039f560 CTR: c0034a20
REGS: ed38bdd0 TRAP: 0700 Tainted: G W (2.6.35.11)
MSR: 00021000 ME,CE CR: 24000888 XER:
TASK = ecb2c260[405] 'ethctl' THREAD: ed38a000 CPU: 1
GPR00: 0001 ed38be80 ecb2c260
