Zitat von Jan Kiszka <[EMAIL PROTECTED]>: > [EMAIL PROTECTED] wrote: >> Zitat von Philippe Gerum <[EMAIL PROTECTED]>: >> >>> The risk in ironing those PCI locks is to run with hw interrupts >>> disabled for a >>> long time, inducing pathological latencies, so running RTAI's >>> latency test in >>> the background should help detecting those peaks. >>> >>> However, we may find nothing bad if the kernel uses the MMConfig >>> access method >>> to the PCI space since this is basically fast mmio there. But since >>> you seem to >>> be running on x86_32, we may want to check whether BIOS or direct >>> access to the >>> PCI config does not raise the typical latency too much, as well (I'm >>> unsure that >>> PCI_GOBIOS will give us decent results though). >>> >>> To sum up: with different settings for the PCI config access method in "Bus >>> options" (by order of criticality, MMConfig then Direct, then maybe >>> BIOS), does >>> the latency tool report pathological peaks? >>> >> >> Hi Philippe >> >> I played with the different PCI configurations and the results are >> devastating. Latencies (and jitter) skyrocket after some minutes of >> testing and peak at several milliseconds. I didn't do the regression >> with 'normal' INTs though, but that's something up next. Additionally >> MMCONFIG produced some strange msg at boot. > > Could you catch some path traces with the ipipe latency tracer when this > happens? See [1] for details. Dunno if RTAI's latency tool is prepared > to support you here (triggering a trace on new peaks), but > CONFIG_IPIPE_TRACE_IRQSOFF should already suffice in this case - if the > latency is due to IRQ disabling over PCI code. > > Thanks, > Jan > > [1] http://www.xenomai.org/index.php/I-pipe:Tracer
I'll have a look. Should be no problem to modify the RTAI testsuite to trigger traces in the event of a new peak. Just moved back to INTs, so I have to rebuild... Will test and report. Bernhard ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ RTnet-users mailing list RTnet-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rtnet-users
