Re: [Xenomai-core] rare brokenness in latency output - FPU bug!

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

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Jeff Webb wrote:
> Jan Kiszka wrote:
>> Uhh, wait! I just fired up switchtest on the same box:
>> ...
>> Gilles, what info do you need? It's all the latest on x86 here:
>> 2.6.17.13 (.config attached), ipipe-1.4, SVN #1646, gcc4.1.0.
>>
>> Jan
> 
> I get a similar result here with xenomai-2.2.3, 2.6.17.13, x86 SMP (see
> below).  No seg fault, though.
> 
> -Jeff
> 
> 
> *
> *
> * Type ^C to stop this application.
> *
> *
> == Testing FPU check routines...
> r0: 1 != 2
> r1: 1 != 2
> r2: 1 != 2
> r3: 1 != 2
> r4: 1 != 2
> r5: 1 != 2
> r6: 1 != 2
> r7: 1 != 2
> == FPU check routines: OK.
> == Threads: sleeper_ufps0-0 rtk0-1 rtk0-2 rtk_fp0-3 rtk_fp0-4
> rtk_fp_ufpp0-5 rtk_fp_ufpp0-6 rtup0-7 rtup0-8 rtup_ufpp0-9 rtup_ufpp0-10
> rtus0-11 rtus0-12 rtus_ufps0-13 rtus_ufps0-14 rtuo0-15 rtuo0-16
> rtuo_ufpp0-17 rtuo_ufpp0-18 rtuo_ufps0-19 rtuo_ufps0-20
> rtuo_ufpp_ufps0-21 rtuo_ufpp_ufps0-22 sleeper_ufps1-0 rtk1-1 rtk1-2
> rtk_fp1-3 rtk_fp1-4 rtk_fp_ufpp1-5 rtk_fp_ufpp1-6 rtup1-7 rtup1-8
> rtup_ufpp1-9 rtup_ufpp1-10 rtus1-11 rtus1-12 rtus_ufps1-13 rtus_ufps1-14
> rtuo1-15 rtuo1-16 rtuo_ufpp1-17 rtuo_ufpp1-18 rtuo_ufps1-19
> rtuo_ufps1-20 rtuo_ufpp_ufps1-21 rtuo_ufpp_ufps1-22
> r0: 2147483648 != 10
> r1: 2147483648 != 10
> r2: 2147483648 != 10
> r3: 2147483648 != 10
> r4: 2147483648 != 10
> r5: 2147483648 != 10
> r6: 2147483648 != 10
> r7: 39868544 != 10
> Error after context switch from task 8(rtup1-8) to task 10(rtup_ufpp1-10),
> FPU registers were set to 39868544 (maybe task ???)
> RTT|  00:00:00
> RTH|---------cpu|ctx switches|-------total
> RTD|           0|          23|          23
> RTD|           1|          28|          28
> 

Welcome to the club!

Everyone's busy behind the curtain to analyse what's going on here. So
far we thought it's a post 2.2.2 regresssion (SVN rev 1595 for trunk,
1597 for 2.2.x), but the issue may be more tricky.

Do you get the switchtest failure also with plain 2.2.2?

What processor do you use? I was only able to trigger my problems on
Pentium MMX and older or an Athlon 800 here. A Pentium III worked fine.

Jan


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