Re: [Xenomai-help] rt_pipe and rt_queue problems

[Jan Kiszka <jan.kiszka@domain.hid>]

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Petr Cervenka wrote:

> ...
> I made a reduced example and the error was still there. So I tried a couple of things and I found out, that new interface rt_queue_write/rt_queue_read is faulty (perhaps only rt_queue_read) or I misused it. I used these functions to speed up the trasfer from rt_pipes/linux devices. "Zero-copy" optimization should come somewhere in near future (or never) ;-)
> When I tried to use rt_queue_alloc/rt_queue_send/rt_queue_receive/rt_queue_free, everything was fine.
> Xenomai version: 2.2.0 with any patches
> Linux: 2.6.17.7, adeos: 2.6.17-i386-1.3-09
> Petr
>
>   
I quick run of your program confirmed that there is something fishy:

[  277.130780] Xenomai: Switching consumer to secondary mode after exception #14 in kernel-space at 0xc01cb6dc (pid 907)
[  277.131489] I-pipe tracer log (30 points):
[  277.131571] func                    0 ipipe_trace_panic_freeze+0x8 (xnpod_fault_handler+0xe1)
[  277.131757] func                  -15 xnpod_fault_handler+0xd (xnpod_trap_fault+0x32)
[  277.131921] func                  -29 xnpod_trap_fault+0x8 (xnarch_trap_fault+0x1f)
[  277.132083] func                  -35 xnarch_trap_fault+0xb (exception_event+0x2d)
[  277.132347] func                  -46 exception_event+0x9 (__ipipe_dispatch_event+0x5e)
[  277.132547] func                  -50 __ipipe_dispatch_event+0xe (__ipipe_handle_exception+0x4d)
[  277.132746] func                  -54 __ipipe_handle_exception+0xb (error_code+0x54)
[  277.132937] func                  -68 __copy_from_user_ll+0xa (__rt_queue_read+0x87)
[  277.133128] func                  -81 __ipipe_restore_pipeline_head+0x8 (xnregistry_fetch+0x79)
[  277.133326] func                  -83 xnregistry_fetch+0x9 (__rt_queue_read+0x44)
[  277.133515] func                  -87 __copy_from_user_ll+0xa (__rt_queue_read+0x3c)
[  277.133855] func                  -96 __rt_queue_read+0xe (hisyscall_event+0x140)
[  277.134047] func                 -107 hisyscall_event+0xe (__ipipe_dispatch_event+0x5e)
[  277.134241] func                 -108 __ipipe_dispatch_event+0xe (__ipipe_syscall_root+0x55)
[  277.134437] func                 -110 __ipipe_syscall_root+0x9 (system_call+0x20)
[  277.134626] func                 -172 ipipe_unstall_pipeline_head+0x8 (xnshadow_harden+0x118)
[  277.134823] func                 -178 xnpod_switch_fpu+0xa (xnshadow_harden+0x105)
[  277.135012] func                 -181 __switch_to+0xe (schedule+0x4b2)

Philippe, can you comment on this?

Jan



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