http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Emc2HardwareDesign#No_buffering
Havent looked into it, but it's stupid for some purposes ..... you could stream to a buffer, and have limitations on how often it would get updated ..... Doesn't seem to hold entirely true either, some people seem to have implemented buffered drivers. / Lars 2012/8/27 Michael Haberler <[email protected]>: > > Am 27.08.2012 um 20:09 schrieb Lars Segerlund: > >> As for virtualisation issues, you said you tested on virtualIbox ?? > > I get the same hangs in halcmd waiting for a mutex both on a real machine and > VB on 2.6.33.7.2-rt30-1-686-bigmem ; havent debugged yet > >> >> I run a 2.2 something which is hacked from old patches, the makefiles >> are the worst to get building, I set rt priorities separately ( post >> launch ), to tune. >> >> The 2.4 patched kernel had some issues if I don't remember wrong, >> however I am quite busy and time goes to new hardware at the moment. >> >> For the rtapi the changes are a couple of files, I just dropped in >> the old patches, looked them over a bit and ran. >> The other Michael, ( of bitmunster ), had newer patches which I ended >> up picking up. >> The rtapi is trivial to implement, since rt-preempt runs in userspace >> and implements POSIX. >> One this is that perhaps a more well thought approach than a quick >> hack would be nice, since then one could incorporate all the 'best >> practices' for rt-preempt. > > hm, I'd be looking for basic build and 'works within rt-preempt limitations' > diffs for the RTAPI layer with an eye towards merging - I want to avoid > importing experimental or undocumented HAL changes > > I guess I'll need to find out who owns these diffs these days, Michael says > he doesnt > >> Run some test programs, and tune the system well before starting ! >> >> As for hal ... no problem .. but Michael changed it a bit. >> ( btw. hal's lack of buffering is stupid IMHO, that is something that >> should be adressed in any linuxcnc3, otherwise great. ). > > What do you mean by "HAL buffering" - please explain? > > -Michael > >> >> btw. I would port it to rt-preempt by myself if it wasn't done, it's >> so much easier to work with than RT-Linux / RTAI .... just a regular >> program on a regular computer ... >> This is my perspective. >> >> Watch out for some platforms, sometimes certain versions gets >> regressions for specific platforms. >> >> But all in all , very undramatic. >> >> >> 2012/8/27 Michael Haberler <[email protected]>: >>> Lars, >>> >>> thanks for the general RT observations (what exactly is a 'viritualisation >>> issue' provided I dont use virtualisation?) >>> >>> can you say anything about the *LinuxCNC* source level changes which >>> happened, in particular to rtapi and hal? >>> >>> - Michael >>> >>> >>> >>> Am 27.08.2012 um 19:29 schrieb Lars Segerlund: >>> >>>> Check out www.osadl.org they have a test rack with timings, for arm, >>>> mips, x86 amd64 and some. >>>> There should be a page to the wiki there to. >>>> >>>> Usually if you have bad hardware or a bad driver it will be a no go, >>>> but if you have good hardware it should work fine, when checking the >>>> numbers remember these systems are under heavy load. >>>> >>>> Also if testing, don't forget to set RT priority ! ( btw. there is a >>>> debian rt-preempt kernel , try it >>>> >>>> So an decent hardware you will not get below 10 us jitter, but >>>> whitout stretching it you should get somewhere between 20-40 depending >>>> on system. >>>> >>>> In general, worse jitter than RT-Linux or RTAI , BUT better worst >>>> cases ..... ie. worst cases are not very frequent, and not as big. >>>> >>>> Try a greater than 3.0 kernel, and I think there are virtualisation >>>> issues ..... please report back ! >>>> >>>> / regards, Lars Segerlund. >>>> >>>> >>>> 2012/8/27 Michael Haberler <[email protected]>: >>>>> >>>>> Am 27.08.2012 um 18:45 schrieb Lars Segerlund: >>>>> >>>>>> I am ... what do you want to know ? >>>>> >>>>> First I would like to understand what the major differences and >>>>> restrictions are; at first glance this looks very similar to a SIM setup >>>>> to me >>>>> >>>>> Also I'd like to figure how mature this is and if it could be a merge >>>>> candidate for LinuxCNC >>>>> >>>>> a README.rt-preempt like "we did this and that" would be stunning ;) >>>>> >>>>> I managed to compile >>>>> git://gitorious.org/emc-rt-preempt/emc-rt-preempt.git branch >>>>> linuxcnc-buesch-rt on a 2.6.31-11-rt kernel (virtualbox) but runtests >>>>> fails on me; I'll retry on a real machine >>>>> >>>>> background: I want a non-RTAI HAL environment to try on smaller devices >>>>> like ARM >>>>> >>>>> - Michael >>>>> >>>>>> >>>>>> / Lars >>>>>> >>>>>> 2012/8/27 Michael Haberler <[email protected]>: >>>>>>> please get in touch with me >>>>>>> >>>>>>> thanks >>>>>>> >>>>>>> -Michael >>>>>>> >>>>>>> >>>>>>> >>>>>>> ------------------------------------------------------------------------------ >>>>>>> Live Security Virtual Conference >>>>>>> Exclusive live event will cover all the ways today's security and >>>>>>> threat landscape has changed and how IT managers can respond. >>>>>>> Discussions >>>>>>> will include endpoint security, mobile security and the latest in >>>>>>> malware >>>>>>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >>>>>>> _______________________________________________ >>>>>>> Emc-developers mailing list >>>>>>> [email protected] >>>>>>> https://lists.sourceforge.net/lists/listinfo/emc-developers >>>>>> >>>>>> ------------------------------------------------------------------------------ >>>>>> Live Security Virtual Conference >>>>>> Exclusive live event will cover all the ways today's security and >>>>>> threat landscape has changed and how IT managers can respond. Discussions >>>>>> will include endpoint security, mobile security and the latest in malware >>>>>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >>>>>> _______________________________________________ >>>>>> Emc-developers mailing list >>>>>> [email protected] >>>>>> https://lists.sourceforge.net/lists/listinfo/emc-developers >>>>> >>>>> >>>>> ------------------------------------------------------------------------------ >>>>> Live Security Virtual Conference >>>>> Exclusive live event will cover all the ways today's security and >>>>> threat landscape has changed and how IT managers can respond. Discussions >>>>> will include endpoint security, mobile security and the latest in malware >>>>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >>>>> _______________________________________________ >>>>> Emc-developers mailing list >>>>> [email protected] >>>>> https://lists.sourceforge.net/lists/listinfo/emc-developers >>>> >>>> ------------------------------------------------------------------------------ >>>> Live Security Virtual Conference >>>> Exclusive live event will cover all the ways today's security and >>>> threat landscape has changed and how IT managers can respond. Discussions >>>> will include endpoint security, mobile security and the latest in malware >>>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >>>> _______________________________________________ >>>> Emc-developers mailing list >>>> [email protected] >>>> https://lists.sourceforge.net/lists/listinfo/emc-developers >>> >>> >>> ------------------------------------------------------------------------------ >>> Live Security Virtual Conference >>> Exclusive live event will cover all the ways today's security and >>> threat landscape has changed and how IT managers can respond. Discussions >>> will include endpoint security, mobile security and the latest in malware >>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >>> _______________________________________________ >>> Emc-developers mailing list >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/emc-developers >> >> ------------------------------------------------------------------------------ >> Live Security Virtual Conference >> Exclusive live event will cover all the ways today's security and >> threat landscape has changed and how IT managers can respond. Discussions >> will include endpoint security, mobile security and the latest in malware >> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >> _______________________________________________ >> Emc-developers mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-developers > > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
