On Thu, 2011-04-28 at 10:33 +0200, Jean-Michel Hautbois wrote: > 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: 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. > > 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 :
The mm switch issue was specifically addressed by this patch, which is part of 2.12-01: http://git.denx.de/?p=ipipe-2.6.git;a=commit;h=c14a47630d62d0328de1957636dceb1d498f7048 However, it the last 2.6.35 patch issued was based on 2.6.35.7, not 2.6.35.11, so there is still the possibility that something went wrong while you forward ported this code. - Please check that mmu_context_nohash.c does contain the fix above as it should - Please try Richard's suggestion, i.e. moving to 2.6.36, which may give us more hints. > Badness at kernel/lockdep.c:2327 > NIP: c006e554 LR: c006e53c CTR: 000186a0 Adeos sometimes conflicts with the vanilla IRQ state tracer. I'll have a look at this. Disable CONFIG_TRACE_IRQFLAGS. -- Philippe. _______________________________________________ Xenomai-core mailing list Xenomai-core@gna.org https://mail.gna.org/listinfo/xenomai-core
