From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: Context Switch in Real Time Linux Vs VxWorks (or any other RTOS) From: Gary Thomas To: okorpil@fh-landshut.de Cc: arun@ossi.co.in, linuxppc embedded In-Reply-To: <40F77AA3.8030703@fh-landshut.de> References: <000001c46af2$642f7c40$e100a8c0@arunprasad> <40F77AA3.8030703@fh-landshut.de> Content-Type: text/plain Message-Id: <1089990598.22193.6417.camel@hermes> Mime-Version: 1.0 Date: Fri, 16 Jul 2004 09:09:58 -0600 Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: On Fri, 2004-07-16 at 00:50, Oliver Korpilla wrote: > Arun Prasad Velu wrote: > > > >I am in the process of analyzing the feasibility of migrating an > >existing VxWorks system (MPC860 target) to Linux (RTOS). > > > >I'd like to compare the features of Linux and VxWorks with respect to > >the Real Time capabilities. I am little concerned about Linux's Context > >Switching. > > > >I'd like to get your opinion on this. Even if I want to move to Linux, > >I'll have to convince my management. So, any pointers on comparison of > >Linux Vs VxWorks with respect to Real Time capabilities would be highly > >appreciated. > > I hardly guess context switching will be your main problem, because the > stock Linux kernel does not support hard realtime! > > You either have to use RTAI (free kernel modification that requires > drivers to be rewritten for realtime), RTLinux (nearly the same, > non-free, patented) or modified Linux kernels from TimeSys or MontaVista > (who both add real-time capabilities in a more stock-Linux-compliant way). > > Depending on your target, eCos (a free embedded operating system with a > focus on minimal code) may be the better choice for you, especially if > your platform is already supported. Thanks for the plug :-) [n.b. I am one of the main eCos developers] FYI, look to http://sources.redhat.com/ecos for details. > > Be warned: Not all PowerPC processors are supported in eCos (last time I > checked 74xx and 7xx were missing). Ah, but they are simple to add (and have been, but not necessarily public) as they are effectively PPC60x processors with some differences. -- Gary Thomas MLB Associates ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/