[LAU] System Configuration: kernel, CPU frequency, hardware timers

[Ralf Mardorf]

On Mon, 27 Aug 2018 13:05:30 -0700, Kevin Cosgrove wrote:
>What I did came from these links:
>
>https://wiki.linuxaudio.org/wiki/system_configuration#the_kernel

Do you want to build a real-time kernel or do you want to stay with the
kernel that already is installed? If you want to build a kernel, you
might also want to care about the tickles config and the timers config.

$ zgrep -i no_hz /proc/config.gz 
CONFIG_NO_HZ_COMMON=y
CONFIG_NO_HZ_IDLE=y
# CONFIG_NO_HZ_FULL is not set
CONFIG_NO_HZ=y

>https://wiki.linuxaudio.org/wiki/system_configuration#cpu_frequency_scaling

It doesn't harm to care about the governor, since it could improve
performance. I don't think you need a loop to set the governor for all
cores.

>https://wiki.linuxaudio.org/wiki/system_configuration#hardware_timers

This most likely is outdated.

$ zgrep -i timer /proc/config.gz 
# Timers subsystem
CONFIG_HIGH_RES_TIMERS=y
CONFIG_POSIX_TIMERS=y
CONFIG_TIMERFD=y
CONFIG_OPROFILE_NMI_TIMER=y
CONFIG_HPET_TIMER=y
CONFIG_X86_PM_TIMER=y
CONFIG_NETFILTER_XT_TARGET_IDLETIMER=m
CONFIG_HW_RANDOM_TIMERIOMEM=m
CONFIG_HANGCHECK_TIMER=m
CONFIG_PPS_CLIENT_KTIMER=m
CONFIG_SND_TIMER=m
CONFIG_SND_PCM_TIMER=y
CONFIG_SND_HRTIMER=m
CONFIG_SND_SEQ_HRTIMER_DEFAULT=y
CONFIG_LEDS_TRIGGER_TIMER=m
CONFIG_IIO_HRTIMER_TRIGGER=m

>My new system runs the 4.17.17 kernel along with the rest of Fedora-27.

/etc/rc.d/ most likely is an outdated location.

What kind of computer are you using, that you care about swappiness?

Maybe you distro migrated from the 'audio' group to a 'realtime'
group.

"@realtime   -  rtprio     99
@realtime   -  memlock    unlimited" -
http://jackaudio.org/faq/linux_rt_config.html

'rtprio 99' sometimes is discussed, but 'memlock unlimited' usually
isn't discussed. YMMV!

-- 
pacman -Q linux{,-rt{-pussytoes,-cornflower,,-securityink}}|cut -d\  -f2
4.18.3.arch1-1
4.18_rc8_rt1-1
4.16.18_rt12-1
4.16.18_rt11-1
4.16.18_rt10-1