From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?J=FCrgen_Mell?= Subject: Re: Problem with function select on kernel 2.6.29.6-rt23 Date: Thu, 10 Sep 2009 13:50:58 +0200 Message-ID: <4AA8E822.5090909@hedrich-winders.com> References: <4AA8D958.5000508@hedrich-winders.com> <921ca19c0909100433s2cad9e6asc6b3a77a7e03aa1a@mail.gmail.com> Reply-To: mell@hedrich-winders.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE To: Sujit K M , linux-rt-users@vger.kernel.org Return-path: Received: from dispoweb.ifw.uni-hannover.de ([130.75.23.4]:50723 "EHLO ketschua.hedrich-winders.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755502AbZIJLu4 convert rfc822-to-8bit (ORCPT ); Thu, 10 Sep 2009 07:50:56 -0400 In-Reply-To: <921ca19c0909100433s2cad9e6asc6b3a77a7e03aa1a@mail.gmail.com> Sender: linux-rt-users-owner@vger.kernel.org List-ID: Thanks for your reply! The machine is not loaded very much (CPU load=20 below 30%) . ANY network traffic, which is not even directed to the=20 server process on the machine will cause the problem, eg. just a copy=20 operation which copies the Linux kernel source from a SMB server to th= e=20 local disk. The application program has established the socket connection. 'bind'=20 has completed without problems. It is then running in a loop where it=20 calls 'select' to wait for new data, reads the data if any is available= ,=20 processes it and then repeats these steps. Bye, J=FCrgen 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 Secon= d > 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, J=FCrgen Mell wrote: > =20 >> Hi, >> >> I have an application which connects via a network socket to a serve= r >> 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 tw= o >> seconds timeout. This works well until there is network traffic on t= he >> external network interfaces (eth* or WLAN). When there is network tr= affic on >> the external interfaces, the select function does not wait anymore b= ut 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 s= elect 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 t= o do it >> this afternoon. Are there any known problems with select? Is there a= ny way >> to circumvent this? >> >> Any help would be greatly appreciated! >> >> J=FCrgen >> >> -- >> J=FCrgen 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 Universit=E4t 2 (im PZH) >> D-30823 Garbsen (GERMANY) >> --------------------------------------------------------------------= -------- >> Gesch=E4ftsf=FChrer: Karsten Adam >> Handelsregister: Wetzlar, HRB 4768 >> Steuernr.: 020/235/20110 USt-IdNr.: DE 258258279 >> --------------------------------------------------------------------= -------- >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-rt-u= sers" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> =20 > > > > =20 --=20 J=FCrgen Mell (Software-Entwicklung) mell@hedrich-winders.com Tel.: +49-511-762-18226 http://www.hedrich-winding.com =46AX : +49-511-762-18225 Mobil: +49-160-7428156 -----------------------------------------------------------------------= ----- HEDRICH winding systems GmbH An der Universit=E4t 2 (im PZH) D-30823 Garbsen (GERMANY) -----------------------------------------------------------------------= ----- Gesch=E4ftsf=FChrer: Karsten Adam Handelsregister: Wetzlar, HRB 4768 Steuernr.: 020/235/20110 USt-IdNr.: DE 258258279 -----------------------------------------------------------------------= -----=20 -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html