Hi Dmitry! On 26.11.2013 15:21, Dmitry Lysenko wrote: > On Marvell Kirkwood at 1.2Ghz and 3.2.51-rt72 kernel I have slightly > better results: > > --- with hackbench: > > root@debian:~/rt-tests# ./cyclictest -l 10000 -i 1000 -n -p 80 -q > T: 0 (10268) P:80 I:1000 C: 10000 Min: 16 Act: 29 Avg: 29 Max: 46 > > --- w/o hackbench: > > root@debian:~/rt-tests# ./cyclictest -l 10000 -i 1000 -n -p 80 -q > T: 0 (12686) P:80 I:1000 C: 10000 Min: 5 Act: 6 Avg: 6 Max: 22 > > -- .config: > CONFIG_TICK_ONESHOT=y > # CONFIG_NO_HZ is not set > CONFIG_HIGH_RES_TIMERS=y > > # CONFIG_CPU_IDLE is not set > > Try to play with: > > # CONFIG_PM_RUNTIME is not set > # CONFIG_ARM_CPU_SUSPEND is not set Thanks, this was helpful. After some tweaks I was able to disable CONFIG_PM_RUNTIME and ARM_CPU_SUSPEND. And after disabling NO_HZ and less CONFIG_DEBUG_xxx options I now have the following results: Idle: # ./cyclictest -l 10000 -i 1000 -n -p 80 -q # /dev/cpu_dma_latency set to 0us T: 0 ( 1382) P:80 I:1000 C: 10000 Min: 12 Act: 141 Avg: 127 Max: 202 Load: # ./cyclictest -l 10000 -i 1000 -n -p 80 -q # /dev/cpu_dma_latency set to 0us T: 0 ( 2777) P:80 I:1000 C: 10000 Min: 26 Act: 167 Avg: 152 Max: 229 So the test now finally has better results on a idle system than on one with heavy system load. The numbers are still far away from your latency values on the 1.2GHz Kirkwood. Does anybody have OMAP3 values at hand to compare? Thanks for your input, Stefan -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
