Re: Kernel Oops
Bunjes Friedemann <[email protected]>
| Newsgroups | gmane.linux.real-time.rtai |
|---|---|
| Message-ID | <[email protected]> |
>> I disabled the high precision timer in my bios and recompiled a fresh patched 3.16 kernel not in preemtible, but in desktop mode. >> Now the module seems to load, but the latency test hangs due to a non-responding module (?): >> > Do not stay hanged on a single task. Try the user latency also and report. > Paolo Hi, sorry, I do not understand. Is the testsuite/kern/latency not supposed to work? -Friedemann > >> [ 74.567982] RTAI[malloc]: global heap size = 2097152 bytes, <BSD>. >> [ 74.595871] , kstacks pool size = 524288 bytes. >> [ 74.595873] RTAI[sched]: hard timer type/freq = APIC/99748998(Hz); default timing: periodic; linear timed lists. >> [ 74.595875] RTAI[sched]: Linux timer freq = 250 (Hz), TimeBase freq = 3191992000 hz. >> [ 74.595877] RTAI[sched]: timer setup = 10 ns, resched latency = 3933 ns. >> >> * >> * >> * Type ^C to stop this application. >> * >> * >> Warning: Error opening /proc/rtai/latency_calibrate >> Couldn't get infos about the module's state. >> RTAI Testsuite - KERNEL latency (all data in nanoseconds) >> RTH| lat min| ovl min| lat avg| lat max| ovl max| overruns >> >> >> What might be the reason for this and how can I debug? >> >> Cheers, >> >> Friedemann >> >>> Am 30.03.2016 um 23:55 schrieb Paolo Mantegazza <[email protected] <mailto:[email protected]>>: >>> >>> Unfortunately this thread went on privately. Likely because of a wrong answer click of mine, apologies. >>> >>> In any case it gives me the chance of remarking a few things related to the support of Linux-3.x.x and now 4.x.x. >>> - RTAI-4 onward) is based on the oneshot mode timing only. I still use periodic timers on data acquisition card to time specific tasks . whituout charging the scheduler with their pacing. >>> - from RTAI-5, i.e the actual VULCANO to be released shortly, there starting/stopping_rt_timer, it is done by rtai_sched onyhow. >>> - in such a view the setting of the hard timer mode its start/stop, both in periodic and oneshot mode, will do nothing; they are just kept for compatibility, so that there is no need to change any existing code >>> - HPET is not used by RTAI but 8259/54 is used in UP mode, even if it is strongly suggested to enable the APIC if available >>> - RTAI does not use the second channel of 8259/54 to emulate a continuously running clock, so a _TSC_is_needed >>> >>> In practice what above restricts the newest RTAI versions to true 586s and onward. For fake 586s and 486 earlier version of RTAI should be used. >>> >>> That said there is no need to disable NO_HZ and high precision/resolution timers if they are available in Linux. >>> >>> Paolo >>> >>> ________________________________________ >>> From: Rtai [[email protected] <mailto:[email protected]>] on behalf of Alec Ari [[email protected] <mailto:[email protected]>] >>> Sent: Wednesday, March 30, 2016 10:37 PM >>> To: RTAI Mailing List >>> Subject: Re: [Rtai] Kernel Oops >>> >>> RTAI should be able to use the 8259/8254 timers unless that's now broken? It's never _needed_ APIC or HPET in the past. If it's broken or not working (buggy hardware / BIOS) try disabling high precision + high resolution event timers in kernel config and BIOS if applicable. Also, to avoid NULL pointer issues, set CONFIG_LSM_MMAP_MIN_ADDR to value 65536. >>> >>> Alec Ari >>> _______________________________________________ >>> Rtai mailing list >>> [email protected] <mailto:[email protected]> >>> https://mail.rtai.org/cgi-bin/mailman/listinfo/rtai <https://mail.rtai.org/cgi-bin/mailman/listinfo/rtai> >>> _______________________________________________ >>> Rtai mailing list >>> [email protected] <mailto:[email protected]> >>> https://mail.rtai.org/cgi-bin/mailman/listinfo/rtai <https://mail.rtai.org/cgi-bin/mailman/listinfo/rtai> >> >> -- >> Dr. rer. nat. Friedemann Bunjes >> EDV Entwicklung und Koordination >> Hertie-Institut für Klinische Hirnforschung >> Zentrum für Neurologie >> Universitätsklinikum Tübingen >> Otfried-Müller-Str. 25 >> 72076 Tübingen >> Tel. +49-7071-29-81999 >> Fax +49-7071-29-25010 >> > -- Dr. rer. nat. Friedemann Bunjes EDV Entwicklung und Koordination Hertie-Institut für Klinische Hirnforschung Zentrum für Neurologie Universitätsklinikum Tübingen Otfried-Müller-Str. 25 72076 Tübingen Tel. +49-7071-29-81999 Fax +49-7071-29-25010 _______________________________________________ Rtai mailing list [email protected] https://mail.rtai.org/cgi-bin/mailman/listinfo/rtai