Messages in this thread | | | Date | Sun, 31 Oct 2004 20:06:21 +0100 | From | Florian Schmidt <> | Subject | Re: [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4] |
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On Sun, 31 Oct 2004 16:59:13 +0100 Florian Schmidt <mista.tapas@gmx.net> wrote:
> p.s. new rtc_wakeup version uploaded, which shows the percentage converted > to usecs (always positive, you need the sign?). btw: with V0.6.2 i sometimes > see jitter > 100% but still no lost irq (/dev/rtc still reports only 1 > delivered irq on next wakeup). I cannot provke lost irqs with -f up to 2048. > With -f 8192 i do get lost irq's [not amazing though].
another update upped. small bugfix (still depended on jack, should work now w/o jack installed) plus minor cosmetic corrections. Here's example output for 2.6.8.1-P9 (under heavy load (multiple finds plus kernel compile plus UI artistics):
~/source/my_projects/rtc_wakeup$ ./rtc_wakeup rtc_wakeup - press ctrl-c to stop freq: 1024 max # of irqs: 0 (run until stopped) jitter threshold: 5% (48 usec) output filename: /dev/null rt priority: 90(91) getting cpu speed 1194913254.155 Hz (1194.913 MHz) # of cycles for "perfect" period: 1166907 (976 usec) setting up ringbuffer setting up consumer thread setting up /dev/rtc locking memory turning irq on, beginning measurement new max. jitter: 1.6% (15 usec) new max. jitter: 1.9% (18 usec) new max. jitter: 2.6% (25 usec) new max. jitter: 2.9% (28 usec) new max. jitter: 3.2% (31 usec) new max. jitter: 3.3% (31 usec) new max. jitter: 3.3% (32 usec) new max. jitter: 3.5% (34 usec) new max. jitter: 3.5% (34 usec) new max. jitter: 3.7% (35 usec) new max. jitter: 4.3% (41 usec) new max. jitter: 4.9% (47 usec) threshold violated: 5.6% (54usec) new max. jitter: 5.6% (54 usec) threshold violated: 5.3% (51usec) done. total # of irqs: 168072 missed irqs: 0 threshold violations: 2 max jitter: 5.6% (54 usec)
So basically like lee said, 7% seems to be a normal upper limit for VP boxes (there might be spikes though).
V0.6.2 looked good, too, until it locked up again (under heavy load with rtc_wakeup running) ;) Will build one with debugging enabled tomorrow.
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