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: 00000000 > TASK = ec5220d0[496] 'sipaq' THREAD: ecfac000 CPU: 1 > GPR00: 00000001 ecfadd90 ec5220d0 ec5df340 ec58a700 00000000 ffffffff 00000003 > GPR08: c04a2d98 00000007 c04a2d98 0067e000 0002f385 1007f1f8 c04a5b40 ecfac040 > GPR16: c04a5b40 c04deb80 c04a2120 c04a2d98 c04a5b40 c04d008c ecfac000 00029000 > GPR24: c04d0000 c04d1e6c 00000001 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 2f800000 409e0128 813b018c 2f830000 39290001 913b018c > 419e0020 8003018c 7c000034 5400d97e <0f000000> 8123018c 3929ffff 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. > It is happening quite randomly... :). Does disabling CONFIG_XENO_HW_UNLOCKED_SWITCH clear this issue? > > Thanks in advance ! > JM > > _______________________________________________ > Xenomai-core mailing list > [email protected] > https://mail.gna.org/listinfo/xenomai-core -- Philippe. _______________________________________________ Xenomai-core mailing list [email protected] https://mail.gna.org/listinfo/xenomai-core
