On 2/12/2013 11:20 AM, Tom Easterday wrote: > On Feb 12, 2013, at 8:35 AM, Tom Easterday <[email protected]> wrote: >> I assume it is still recommended that one turn off hyperthreading and/or add >> isolcpus to the kernel? > > My latency numbers (Intel Atom D2700MUD) are horrible (Base thread 119,168 > ns) without any modification. I disabled Hyperthreading in bios and now base > is 19,418 ns after running for an hour or so whilst using the machine. I > still wonder if isolcpus works with Xenomai or if there is a different/better > way to do that? > > I assume this won't work since it is based on rtai kernel: > http://wiki.linuxcnc.org/cgi-bin/wiki.pl?The_Isolcpus_Boot_Parameter_And_GRUB2 > > -Tom > >
Hi, Tom. I wrote that bit of turgid prose about the boot parameter so I feel honor-bound to reply:-) A simplified sequence of events is that once the BIOS + first stage GRUB2 booting finishes, GRUB2 selects and boots a Linux kernel. The instructions to GRUB2 for doing this is contained in /boot/grub/grub.cfg. My wiki page merely addresses how to deal with the GRUB2 way of doing things compared to classic GRUB. The isolcpus parameter is one of many optional boot parameters which can be passed to the kernel for it to process as it initializes (see https://www.kernel.org/doc/Documentation/kernel-parameters.txt). Whether or not one chooses to follow my approach to setting this parameter, the isolcpus parameter is merely passed to the kernel, whatever the kernel may be. To the best of my knowledge (but, hey, I've been known to be wrong once or twice before) both the kernel+RTAI and the kernel+Xenomai deal with this parameter in the same way. Regards, Kent ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
