Thats good news, thank you Remy! I was able to run cyclictest \\\"cyclictest -t1 -p 80 -n -i 10000 -l 1000\\\" an thw maximum latencies were about 650us. However the intervall timers \\\"cyclictest -t1 -p 80 -i 10000 -l 1000\\\" result in abou 3000us maximum latencies. Is it common that interval timers have higher latencies and could this values be reasonable for a 72MHz arm7tdmi (ARMv4T). Anyone has any values to compare or can tell me if those values are reasonable? Kind Regards Johannes Bauer ----- Original von: Remy Bohmer > Hi, 2011/4/15 Johannes Bauer <hannes_bauer@xxxxxx>: > Hi everybody! > > I downloaded the newest uClinux dist a while ago and compiled it with 2.6.33 kernel and the 2.6.33.7.2-rt30 patch applied. > Then i by hand implemeted an old patch for arm lpc22xx machine (ARMv4T), since i am running a lpc2478 board from embedded artists. > I had to implement a clockevent/source timer to add hrtimer support. I compiled it all with uClibc since it as a NOMMU system. > > Now i have some questions: > Is it possible to run the preempt-rt patch with the uClinux distribution and uClibc? The preempt-RT patch runs just fine with a uClibc userspace, I have no idea what it will do in a NOMMU system (never tried it) > I read a few times that if doesnt support PI mutexes, but arent those RT mutexes part of the kernel? The kernel itself has PI-mutexes support, _internally_within_ the kernel; regardless what type of userspace C-library is being used. However, for _userspace_ PI-mutexes, you will need a C-library that supports it (search for example for PTHREAD_PRIO_INHERIT in the library code). 2 options: * Glibc since version 2.5 (actually 2.4.90 and higher) * uClibc master. You might have some luck since there is now NPTL support in uClibc master. So, get the master tree of uClibc and see if it works for you. (http://git.uclibc.org/uClibc/snapshot/uClibc-master.tar.gz) I have not tested it myself though, but if it works, please share the good news. Have Fun! Remy -- To unsubscribe from this list: send the line \\\"unsubscribe linux-rt-users\\\" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html ----- Ende der weitergeleiteten Nachricht ----- -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
