Con Kolivas <[EMAIL PROTECTED]> writes: > Jack O'Quin wrote: >> Con Kolivas <[EMAIL PROTECTED]> writes: >> >>>This patch for 2.6.11-rc1 provides a method of providing real time >>>scheduling to unprivileged users which increasingly is desired for >>>multimedia workloads. >> I ran some jack_test3.2 runs with this, using all the default >> settings. The results of three runs differ quite significantly for no >> obvious reason. I can't figure out why the DSP load should vary so >> much. These may be bogus results. It looks like a libjack bug >> sometimes >> causes clients to crash when deactivating. I will investigate more >> tomorrow, and come up with a fix. >> For comparison, I also made a couple of runs using the realtime-lsm >> to >> grant SCHED_FIFO privileges. There was some variablility, but nowhere >> near as much (and no crashes). I used schedtool to verify that the >> jackd threads actually have the expected scheduler type. > > Thanks for those. If you don't know what to make of the dsp variation > and the crashing then I'm not sure what I should make of it > either. It's highly likely that my code still needs fixing to ensure > it behaves as expected. Already one bug has been picked up in testing > with respect to yield() so there may be others. By design, if you set > iso_cpu to 100 it should be as good as SCHED_RR. If not, then the > implementation is still buggy.
I fixed that bug in libjack, eliminating the crashes on disconnect. They must have been perturbing the numbers quite a bit. Here are three more runs (all SCHED_ISO). The results are much more consistent. The only significant anomaly I see now is that small Delay Max in the first run. *** Terminated Wed Jan 19 01:04:55 CST 2005 *** ************* SUMMARY RESULT **************** Total seconds ran . . . . . . : 300 Number of clients . . . . . . : 20 Ports per client . . . . . . : 4 Frames per buffer . . . . . . : 64 ********************************************* Timeout Count . . . . . . . . :( 1) ( 5) ( 3) XRUN Count . . . . . . . . . : 2 16 15 Delay Count (>spare time) . . : 0 0 0 Delay Count (>1000 usecs) . . : 0 0 0 Delay Maximum . . . . . . . . : 11932 usecs 101053 usecs 98719 usecs Cycle Maximum . . . . . . . . : 868 usecs 1099 usecs 887 usecs Average DSP Load. . . . . . . : 37.9 % 33.6 % 36.0 % Average CPU System Load . . . : 10.2 % 9.0 % 9.9 % Average CPU User Load . . . . : 24.5 % 22.7 % 23.0 % Average CPU Nice Load . . . . : 0.0 % 0.0 % 0.0 % Average CPU I/O Wait Load . . : 0.6 % 3.4 % 0.4 % Average CPU IRQ Load . . . . : 0.7 % 0.7 % 0.7 % Average CPU Soft-IRQ Load . . : 0.0 % 0.0 % 0.0 % Average Interrupt Rate . . . : 1688.1 /sec 1696.1 /sec 1685.2 /sec Average Context-Switch Rate . : 11727.9 /sec 10642.4 /sec 11568.3 /sec ********************************************* I should probably experiment with higher thresholds on the SCHED_ISO class. -- joq - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
