Re: Problem with function select on kernel 2.6.29.6-rt23

["Jürgen Mell" <mell@hedrich-winders.com>]

Thanks for your reply! The machine is not loaded very much (CPU load 
below 30%) . ANY network traffic, which is not even directed to the 
server process on the machine will cause the problem, eg. just a copy 
operation which copies the  Linux kernel source from a SMB server to the 
local disk.
The application program has established the socket connection. 'bind' 
has completed without problems. It is then running in a loop where it 
calls 'select' to wait for new data, reads the data if any is available, 
processes it and then repeats these steps.

Bye,
          Jürgen


Sujit K M wrote:
> Could you Check the sort of load that your server machine is able to
> take. The site you would be looking at is
> http://www.petefreitag.com/item/689.cfm.
> I think if the network is rejecting the select call, As the socket is
> not getting created. Other wise it would wait to the required 2 Second
> limit set by you.
> Also are you sure of the bind part of the socket creation. Making it
> threaded is an option.
>
> Thanks,
> Sujit
>
> On Thu, Sep 10, 2009 at 4:17 PM, Jürgen Mell <mell@hedrich-winders.com> wrote:
>   
>> Hi,
>>
>> I have an application which connects via a network socket to a server
>> running on the same machine (IP 127.0.0.1) This application uses the
>> function 'select' to wait for new data from the server or until a two
>> seconds timeout. This works well until there is network traffic on the
>> external network interfaces (eth* or WLAN). When there is network traffic on
>> the external interfaces, the select function does not wait anymore but it
>> returns with a return code of zero, indicating not data available on the
>> socket. This happens nearly immediately (after 8 to 9 microseconds) and not
>> after the specified two seconds interval. The timeout parameter of select is
>> updated accordingly (it shows eg. 1 s 999991 us).
>> Up to now I could not test this with another kernel but I will try to do it
>> this afternoon. Are there any known problems with select? Is there any way
>> to circumvent this?
>>
>> Any help would be greatly appreciated!
>>
>>       Jürgen
>>
>> --
>> Jürgen Mell (Software-Entwicklung)       mell@hedrich-winders.com
>> Tel.:  +49-511-762-18226                 http://www.hedrich-winding.com
>> FAX :  +49-511-762-18225
>> Mobil: +49-160-7428156
>> ----------------------------------------------------------------------------
>> HEDRICH winding systems GmbH
>> An der Universität 2 (im PZH)
>> D-30823 Garbsen (GERMANY)
>> ----------------------------------------------------------------------------
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>>     
>
>
>
>   


-- 
Jürgen Mell (Software-Entwicklung)       mell@hedrich-winders.com
Tel.:  +49-511-762-18226                 http://www.hedrich-winding.com
FAX :  +49-511-762-18225
Mobil: +49-160-7428156
----------------------------------------------------------------------------
HEDRICH winding systems GmbH
An der Universität 2 (im PZH)
D-30823 Garbsen (GERMANY)
----------------------------------------------------------------------------
Geschäftsführer: Karsten Adam
Handelsregister: Wetzlar, HRB 4768
Steuernr.: 020/235/20110                 USt-IdNr.: DE 258258279
---------------------------------------------------------------------------- 


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