[arch-proaudio] cyclictest

[Ralf Mardorf]

On Fri, 22 Dec 2017 20:54:47 +0100, LX wrote:
>On Fri, 22 Dec 2017 06:33:11 +0100, Ralf Mardorf wrote:

>Intel(R) Core(TM) i5-3317U CPU @ 1.70GHz
>4.14.6-rt7-1-rt
>[root at pill-mobile4 gimmeapill]# cyclictest -S -m -p98
># /dev/cpu_dma_latency set to 0us
>policy: fifo: loadavg: 0.10 0.06 0.02 1/161 521
>Max:      15

>>Intel(R) Celeron(R) CPU G1840 @ 2.80GHz
>>4.14.6-rt7-1-rt
>>cyclictest -S -m -p98
>>WARN: open /dev/cpu_dma_latency: Permission denied
>>policy: fifo: loadavg: 0.13 0.09 0.02 1/208 4690          
>>
>>T: 0 ( 1245) P:98 I:1000 C:35539474 Min:      1 Act:   31 Avg:   27
>>Max:      83

Hi,

does the CPU make such a big difference? If so, I'll order another CPU
today. Or is it the combination of CPU and mobo that does cause such a
big difference?

Is there a reason to run cyclictest as root? We do audio work as an
user without root privileges.

This short run already seems to answer my questions:

[root at archlinux rocketmouse]# uname -rm
4.14.6-rt7-1-rt x86_64
[root at archlinux rocketmouse]# cyclictest -S -m -p98
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 0.00 0.02 0.00 1/254 10107          

T: 0 (10106) P:98 I:1000 C:   8583 Min:      1 Act:    1 Avg:    1 Max:       6
T: 1 (10107) P:98 I:1500 C:   5720 Min:      1 Act:    1 Avg:    1 Max:       6
^C[root at archlinux rocketmouse]#

However, regarding my questions the manpage of cyclictest isn't helpful.

Regards,
Ralf