UbuntuStudio/audio-settings/kernel - Ubuntu Wiki

Source: https://wiki.ubuntu.com/UbuntuStudio/audio-settings/kernel

kernel

../UbuntuStudio/audio-settings

Discussion about kernels and kernel configurations here..

Kernel Testing

Building your own kernel

A short description of how to build a kernel for testing.

linux-lowlatency

Shipped with Ubuntu Studio since 12.04 Precise. Principally a standard Ubuntu kernel (no additional patches to the code, allthough the linux-lowlatency shipped with precise includes a minor patch).

Configurations of interest for linux-lowlatency

These configs need to be somewhat documented and tested

To enable low latency (needs to be expanded)

CONFIG_PREEMPT

conflicts with: CONFIG_PREEMPT_NONE

conflicts with: CONFIG_PREEMPT_VOLUNTARY

To enable this option edit the config file to have these line read:

CONFIG_PREEMPT=y

# CONFIG_PREEMPT_NONE

# CONFIG_PREEMPT_VOLUNTARY

May reduce latency

CONFIG_PREEMPT_RCU

CONFIG_PREEMPT_RCU=y

additional, related configs

CONFIG_TREE_PREEMPT_RCU

CONFIG_RCU_BOOST

CONFIG_RCU_CPU_STALL_DETECTOR

CONFIG_RCU_CPU_STALL_VERBOSE

as configure in current -lowlatency..

CONFIG_TREE_PREEMPT_RCU=y

# CONFIG_RCU_BOOST is not set

# CONFIG_RCU_CPU_STALL_DETECTOR is not set

# CONFIG_RCU_CPU_STALL_VERBOSE is not set

To enable the use of the rtirq script to change rtprio for devices:

this enables the use of threadirqs as a kernel boot parameter

CONFIG_IRQ_FORCED_THREADING

optionally, to make threadirqs a default boot parameter

CONFIG_CMDLINE

depends on: CONFIG_CMDLINE_BOOL

To enable these options edit the config file to have these line read:

IRQ_FORCED_THREADING=y

CONFIG_CMDLINE="threadirqs"

CONFIG_CMDLINE_BOOL=y

High resolution timer:

(Not exactly sure which of CONFIG_HZ=1000 and CONFIG_HZ_1000=y depend on which. )

CONFIG_HZ_1000

CONFIG_HZ

depends on: CONFIG_NO_HZ

to enable high resolution timer

CONFIG_HZ_1000=y

CONFIG_HZ=1000

# CONFIG_NO_HZ is not set

(optionally, tickless timer - add the config here)

Need to be investigated

CONFIG_NTP_PPS

CONFIG_SLAB

CONFIG_PREEMPT_NOTIFIERS

CONFIG_EXPERT

CONFIG_PREEMPT_TRACER

CONFIG_DEBUG_KERNEL

as used in current -lowlatency

# CONFIG_NTP_PPS is not set

CONFIG_SLAB=y

CONFIG_PREEMPT_NOTIFIERS=y

# CONFIG_EXPERT is not set

# CONFIG_PREEMPT_TRACER is not set

# CONFIG_DEBUG_KERNEL is not set

Additional configs

linux-rt

Not in Ubuntu repo since 9.10 Karmic.

UbuntuStudio/audio-settings/kernel (last edited 2012-07-23 10:58:24 by 90-230-166-102-no35)