Hello Charles, MRG is a redhat product for Messaging/Realtime/Grid. They've packaged all this together for use with financial applications, but its only the realtime bit which has most use for scientific applications (possibly messaging). SL5 distros are here: http://glitesoft.cern.ch/cern/mrg/slc5X/i386/RPMS/repoview/mrg-realtime.group.html We manually patched CentOS 5 with the realtime kernel (i.e. without this RPM) and did some speed trials. Generally, it works very well, although not 100% deterministic/guaranteed. The trial machine was a dual Xeon X5550 2.66GHz (8 CPU cores). Without the RT kernel, we averaged 1ms thread wakeup/latency. With the RT kernel, this dropped to typical 5uS latency, but with occasional 'spikes' up to 60uS. I suspect these spikes are due to the processors NMI/SSI interrupts kicking in, which there is little the kernel can do about. The real killer test was running again with Hyperthreading enabled. This gives a total 16 virtual CPU's. Without RT, latency was 1.04mS. With RT this dropped to 8uS average, but spiking up to 134uS. Mat -----Original Message----- From: Charles ELSAESSER WebmailOrange [mailto:[log in to unmask]] Sent: 13 May 2011 11:04 To: Mathew Maher Cc: [log in to unmask] Subject: re: MRG / Realtime with SL6 Bonjour, It would have been nice and usefull if you had given links to packages, docs, patches for kernel-rt (et al) packages available for SLXXX if you know them. What does MRG stands for? Thank you. Charles -------------- > Message du 13/05/11 10:20 > De : "Mathew Maher" > A : [log in to unmask] > Copie à : > Objet : MRG / Realtime with SL6 > > Hi Guys, > Has anyone attempted to patch SL6 into realtime yet? > > I'm specifically referring to the kernel-rt (et al) packages available > ... This e-mail and any attachments may contain confidential and privileged information. If you are not the intended recipient, please notify the sender immediately by return e-mail, delete this e-mail and destroy any copies. Any dissemination or use of this information by a person other than the intended recipient is unauthorized and may be illegal.