From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <48899AB5.4080306@domain.hid> Date: Fri, 25 Jul 2008 11:19:49 +0200 From: Philippe Gerum MIME-Version: 1.0 References: <5D63919D95F87E4D9D34FF7748CE2C2A0137F8FD@ARVMAIL1.mra.roland-man.biz> In-Reply-To: <5D63919D95F87E4D9D34FF7748CE2C2A0137F8FD@ARVMAIL1.mra.roland-man.biz> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] Thread policy and priority in secondary mode Reply-To: rpm@xenomai.org List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: roderik.wildenburg@domain.hid Cc: xenomai@xenomai.org roderik.wildenburg@domain.hid wrote: >>>> __real_pthread_setschedparam(). Note: this will propagate the >>>> priority to the underlying Xenomai thread as well. >>>> >>> Does this mean that the Xenomai thread will run with the new (Linux) >>> priority when it returns to primary mode ? >> Yes. However, the propagation only occurs when the skin and Linux have >> compatible priority scales, which is the case with the POSIX skin. >> >>> And the other way round : >>> when a posix thread switches to secondary mode (without using >>> __real_pthread_setschedparam), does it run in Linux with >> the priority >>> set in Xenomai (with pthread_setschedparam)? >> Yes. >> >>> Or better : what is the Linux-prority when a Xenomai thread >> (posix or or >>> any other Xenomai thread)switches to secondaary mode ? >>> >> It depends on the skin. When the priority scales are >> compatible (i.e. a given >> priority level exists in both and scales are both upwarding, >> like POSIX skin <-> >> Linux, and native skin <-> Linux), you get the same priority >> level in both >> modes, and changing the priority from one mode affects the >> other mode as well. >> >> When they are not compatible, the skin-based priority is >> "normalized" and >> applied to the Linux side when needed (e.g. when VxWorks >> taskPrioritySet() is >> invoked), but __real_pthread_setschedparam does not trigger >> the converse >> propagation (since 2.4.4 actually, because experience showed >> that propagating in >> that case made little sense, and would beget weird >> behaviours). The way priority >> levels are normalized depends on the skin. >> > > Do you know how a Linux priority, set with pthread_setschedparam > (real_pthread_setschedparam), > correlates with the priorities shown by "ps l". In our case we realized > that ps does not show the priority set with pthread_setschedparam. Is > there a command which shows the "real" priority ? > Try this: ps -eo pid,tid,class,rtprio,pri,stat,comm The priority level you want to look at is listed under the RTPRIO column, not the PRI one. Xenomai-wise, do $ cat /proc/xenomai/sched The first value of the PRI field (== ps's RTPRIO) is the priority value according to the nucleus core (0-257 range); when skin priority levels have to be normalized to fit the Linux scale, a second value between parenthesis is appended, giving the original, non-converted, level set by the skin. > Best regrads > Roderik > > Achtung: Neue E-Mail-Adresse! Attention: New e-mail-address! roderik.wildenburg@domain.hid > -------------------------------------------------------- > manroland AG > Vorsitzender des Aufsichtsrates: Hanno C. Fiedler > Vorstand: Gerd Finkbeiner (Vorsitzender), Dr. Ingo Koch, Dr. Markus Rall, Paul Steidle > Sitz der Gesellschaft: Offenbach am Main, Registergericht: Amtsgericht Offenbach HRB-Nr. 42592 > USt-Ident-Nr. DE 250200933 > > _______________________________________________ > Xenomai-help mailing list > Xenomai-help@domain.hid > https://mail.gna.org/listinfo/xenomai-help > -- Philippe.