Re: %openmosix and sata

Dear Felipe,
I runned your test file hundreds of time on my machines... without problems.
But when I try to launch the test with this command:
 mosrun -5 ./test.sh
I've got the segmentation fault. :-(
However... I'm waiting the 2.6.x version for a long time... but It is
still in alpha version :-( and I prefer to remain with my patched kernel
until the 2.6.x is not released officialy.
This is the error:

Unable to handle kernel NULL pointer dereference at virtual address 0000001c
 printing eip:
c01661b2
*pde = 00000000
Oops: 0002
CPU:    0
EIP:    0010:[<c01661b2>]    Not tainted
EFLAGS: 00010286

But I don't understand what means... and where do I have to look for in
the kernel code.
In my kernel the bug arise when I launch the 'mosrun -5' command... but
I don't know where is the corresponding code executed... and how to find
out the bug :-(

Ciao,
Gianluca


Felipe ha scritto:
> Hi Gianluca
>
> Thanks for your answer
>
> I follow have the same problem ....
>
> I try to explain the problem:
>
> My script test.sh:
>    for i in 1 2 3 4 5 ; do 
>       awk 'BEGIN {for(i=0;i<10000;i++)for(j=0;j<10000;j++);}' &
>
>    done
>
> My cluster have 2 nodes, when i run above the script, the first time its ok,
> but when i run it more times is when i get segmentation fault. Example:
>
> openmosix-1 ~ # ./test.sh
> openmosix-1 ~ # ./test.sh
> Segmentation fault
>
>
>
> I begin to read the kernel-hacking howto... and find it:
>
> dmesg return an "Oops:0002" and "EIP:    0010:[<c01675b7>]", but I don't
> find "Oops:0" and "EIP:  0010:[<c01675b7>]" in System.map... why ???? I
> dont know
>
> If you could help me, I try to modify your patch.
>
>
>
> Maybe a solution for my problem is:
>
> Install om for kernel 2.6; but it is not recomendable for production ...
> what do you thing about it?
>
>
> Thanks in advance
>
> Sorry for my english
>
>
> El mar, 04-07-2006 a las 10:07 +0200, Gianluca escribió:
>   
>> Dear Felipe,
>> I know that there are some bugs in my kernel patch :-(
>> but I'm not an expertise of kernel hacking... so I don't know how degub
>> linux kernel and find where is the bug! :-(
>> Months ago, I wrote on the mailing-list... saying that I've prepared
>> this patch and I asked to community to help me in debugging and
>> stabilizing my patch for 2.4.31 kernel...
>> ... but I didn't get any help :-( :-(
>> Seems that people using openmosix are not expertise of kernel
>> debugging... and obviously the main developers don't spent time for
>> debugging 2.4.x series :-(
>> However, my cluster based on my patch runs from several months without
>> stops!! :-) :-)
>> For avoid the bug... don't run the mosrun command with the flag for
>> migrate the job.
>> For example, if you launch the command:
>>  mosrun -4 heavyJob
>> from a node different to 4... then you'll see the Segmentation Fault :-(
>> So... if you never use that command... all things go well ;-) ... in
>> fact, the automatic migration works well.
>>
>> Ciao,
>> Gianluca
>>
>> Felipe ha scritto:
>>     
>>> Thanks
>>>
>>> I try with it and the sata disk is ok, but when i probe the om with the
>>> next script:
>>>
>>>   for i in 1 2 3 4 5 ; do 
>>>      awk 'BEGIN {for(i=0;i<10000;i++)for(j=0;j<10000;j++);}' &
>>>   done
>>>
>>>
>>> When i run the script, its ok, but the next run display the next
>>> message:
>>>
>>>         Segmentation fault
>>>         
>>> dmesg returns:
>>>
>>>         <1>Unable to handle kernel NULL pointer dereference at virtual
>>>         address 0000001c
>>>          printing eip:
>>>         c01675b7
>>>         *pde = 00000000
>>>         Oops: 0002
>>>         CPU:    0
>>>         EIP:    0010:[<c01675b7>]    Not tainted
>>>         EFLAGS: 00010286
>>>         eax: 0000001c   ebx: f756c000   ecx: 00000000   edx: ffff0001
>>>         esi: 080ed000   edi: 080e8000   ebp: f756dd34   esp: f756da34
>>>         ds: 0018   es: 0018   ss: 0018
>>>         Process test.sh (pid: 1705, stackpage=f756d000)
>>>         Stack: f756da38 00000000 00000000 f59bf920 080e2000 c016c5ee
>>>         080e7d74 080ec93c
>>>                00005d74 00000003 00001812 0000009a f760a000 f762003c
>>>         f6457b58 00000000
>>>                00011e8c f6457bc0 00000001 060c0705 00000003 c02b5fac
>>>         f6457b00 f756c000
>>>         Call Trace:    [<c016c5ee>] [<c02b5fac>] [<c02af770>]
>>>         [<c016c1c0>] [<c015136d>]
>>>           [<c0150f6c>] [<c016a33f>] [<c01404eb>] [<c016a130>]
>>>         [<c015136d>] [<c015153d>]
>>>           [<c0105ba2>] [<c010a18f>] [<c01d5ffb>] [<c0105b60>]
>>>         [<c01d4a97>] [<c01da988>]
>>>           [<c010a06a>]
>>>         
>>>         Code: 0f c1 10 85 d2 0f 85 9a 15 00 00 89 3c 24 29 fe 89 74 24
>>>         04
>>>
>>> My cluster have 2 nodes
>>>
>>> I compile the kernel with differents optios, but the result is the same.
>>>
>>> I have many questions, for example:
>>>
>>> om have support for my hardware?
>>> Maybe the om conigurations is bad
>>> My filesystem is Reiser 3.x .... is it the problem?
>>> ?????
>>>
>>> any help is good for me 
>>>
>>> thanks in advance
>>>
>>>
>>>
>>>
>>> El sáb, 01-07-2006 a las 09:54 +0200, Gianluca escribió:
>>>   
>>>       
>>>> I have patched the 2.4.31 kernel... to resolving the same problem.
>>>> attached you'll find my patch... you can try it ;-)
>>>>
>>>> Felipe ha scritto:
>>>>     
>>>>         
>>>>> I tried that also, but my pc's have the  I/O Controller Hub 7 and the
>>>>> libata patch for kernel 2.4.26 doesnt have support for it.
>>>>>
>>>>> then which is the best versio of om for my pc's?
>>>>>
>>>>> Do you now how can i patch the kernel 2.4.26 with the newest libata
>>>>> patch?
>>>>>
>>>>>
>>>>>
>>>>> El mié, 28-06-2006 a las 17:09 -0500, Brian English escribió:
>>>>>   
>>>>>       
>>>>>           
>>>>>> I have tried using the Gentoo Openmosix Kernels.  Try your best to
>>>>>> avoidthese, especially the 2.4.30 one, as they are unstable at best.
>>>>>> I would get segfaults while running the OpenMosixTest package as well
>>>>>> as using the cluster to encode wav files to flac files. Your best bet
>>>>>> is to manually install the latest stable version from the site
>>>>>> (2.4.26) and patch the kernel for SATA support (I'm not sure on how to
>>>>>> do that, but I think it can be done).
>>>>>>     
>>>>>>         
>>>>>>             
>>>>>   
>>>>>
>>>>>
>>>>>
>>>>> Using Tomcat but need to do more? Need to support web services, security?
>>>>> Get stuff done quickly with pre-integrated technology to make your job easier
>>>>> Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
>>>>> http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
>>>>> _______________________________________________
>>>>> openMosix-general mailing list
>>>>> openMosix-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
>>>>> https://lists.sourceforge.net/lists/listinfo/openmosix-general
>>>>>
>>>>>   
>>>>>       
>>>>>           
>>> Using Tomcat but need to do more? Need to support web services, security?
>>> Get stuff done quickly with pre-integrated technology to make your job easier
>>> Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
>>> http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
>>> _______________________________________________
>>> openMosix-general mailing list
>>> openMosix-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
>>> https://lists.sourceforge.net/lists/listinfo/openmosix-general
>>>
>>>   
>>>       
>
>
>   


Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642