Discussion about kernels and kernel configurations here..
Building your own kernel
A short description of how to build a kernel for testing.
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)
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
additional, related configs
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
optionally, to make threadirqs a default boot parameter
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. )
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
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
Not in Ubuntu repo since 9.10 Karmic.