I know that, I was wondering about BeagleBone specific stuff like the cape manager, BoneScript, etc. If it has all the features of 4.1.x-ti plus the rt patches without breaking anything, unless there are clear benchmarks showing -rt is inferior for some workloads, why not just consolidate. If there are, it'd be nice to have it mentioned in the blurb to help guide a choice.
As I said my current project only cares about the kernel version if it changes /sys/class/ directory layouts or names, but for some future ideas better performing Posix real-time code might be nice. I'll play around a bit and see if I notice anything, but I've got to put this aside for about a week, I wanted to ask before I put things on hold. Its complicated but in the past I've had some -rt kernels show worse peak latency with real-time Posix code than without. I understand the -rt patches don't make the kernel suitable for "hard" real-time but if I can keep the worst case latency below about 20% of my servo loop and infrequent enough, it'd work for what I've in mind and be way easier to deal with than Xenomi kernels. I've used the old rtl-3.1 patches (I believe to 2.2.x) many years ago for a hard real-time application that ran for about 15 years in labs on all three coasts -- it was basically "set and forget", it just ran, but if I'd needed to update kernels maintenance would have been a nightmare, since it was only on an isolated network with no outside connectivity this was OK, Once I installed the boxes I never touched them again. -- they just worked until retired which was most gratifying. --wally. On Wednesday, March 2, 2016 at 12:01:27 AM UTC-6, john3909 wrote: > > rt refers to the real-time option: > > https://rt.wiki.kernel.org/index.php/RT_PREEMPT_HOWTO > > Regards, > John > > > > > On Mar 1, 2016, at 8:57 PM, Wally Bkg <[email protected] <javascript:>> > wrote: > > I've just booted 2016-02-21 lxqt 8.3 image to get a "dpkg > --get-selections >/backup/package-selections" list of what I need to > install on my console 8.2 2015-11-12 image to upgrade to the current > testing image without starting over. > > I noticed that 2016-02-21 8.3 lxqt kernel is 4.1.x-ti-rt whereas > 2015-11-12 8.2 console was 4.1.x-ti kernel. > > kernel options blurb at: > http://elinux.org/Beagleboard:BeagleBoneBlack_Debian#4.1.x-ti > > says "it is slated to replace the v3.8.x tree in Debian Jessie, cape > manager support is enabled", why the -rt variant now? > > My current project (BBW running on 2015-11-12) has pretty much zero > dependence on kernel version, other than any changes in /sys/class/ > directory layout, as its pure C code using a bunch of gpio pins, but I'd > like to track Jessie as improvements in things like BoneScript and Node-Red > would help a friend with a project -- I've got him started with 3.8.x lxde > 7.9 2015-11-12 image on a BBG, while all the "improvements" seem to be in > 8.x Debian. > > --wally. > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > For more options, visit https://groups.google.com/d/optout. > > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
