2011/5/2 Philippe Gerum <r...@xenomai.org>: > On Mon, 2011-05-02 at 11:56 +0200, Jean-Michel Hautbois wrote: >> 2011/5/2 Jean-Michel Hautbois <jhautb...@gmail.com>: >> > 2011/4/30 Philippe Gerum <r...@xenomai.org>: >> >> On Fri, 2011-04-29 at 18:08 +0200, Jean-Michel Hautbois wrote: >> >>> 2011/4/29 Philippe Gerum <r...@xenomai.org>: >> >>> > 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 >> >>> >> >>> It is ok, I have the fix. >> >> >> >> Does 2.6.35.7-2.12-02 exhibit the issue as well? >> > >> > It doesn't seem to exhibit the issue... I didn't try during a long >> > time though... >> > >> >>> >> >>> > - Please try Richard's suggestion, i.e. moving to 2.6.36, which may >> >>> > give >> >>> > us more hints. >> >>> >> >>> It is better. I don't have the badness on mmu context anymore. >> >>> This gives some hints ;). >> >>> >> >> >> >> Yes and no. The mmu management code involved was untouched between >> >> 2.6.35 and 2.6.36, so I still don't get why this activity counter gets >> >> trashed yet. >> >> >> >>> >> 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. >> >>> >> >>> Yes, but I *want* to have the CONFIG_TRACE_IRQFLAGS on. I just wanted >> >>> to tell that I had the problem, in order to be sure it is known ;). >> >>> >> >> >> >> Sure, but one issue at a time. >> >> >> >>> JM >> >> >> >> -- >> >> Philippe. >> >> >> >> OK, the badness disappears, but the 2.6.36 kernel seems more stable >> than 2.6.35 with this patch. > > What does "more stable" mean? Do you have lockups, any issue reported in > the kernel log? Any weird Xenomai behavior? >
Well, my applications work very well with the 2.6.36, comparing to the 2.6.35 were it can crash without any informative message. I can't say much more because I don't have much more :). JM _______________________________________________ Xenomai-core mailing list Xenomai-core@gna.org https://mail.gna.org/listinfo/xenomai-core
