Real-time linux kernel

[Artyom]

@umiddelb
Hi again Uli!

Try to recompile the kernel with these options:

...
# RCU Subsystem
(OK) CONFIG_TREE_PREEMPT_RCU=y
(OK) CONFIG_PREEMPT_RCU=y
...
# Kernel Features
(OK) CONFIG_PREEMPT=y
(OK) CONFIG_PREEMPT_RT_BASE=y
(Not present) CONFIG_HAVE_PREEMPT_LAZY=y
(Not present) CONFIG_PREEMPT_LAZY=y
.....
(Not present) CONFIG_PREEMPT_RT_FULL=y
(OK) CONFIG_PREEMPT_COUNT=y
(ARMv7 only, 3.12+ only)CONFIG_HZ_FIXED=0
(MIPS only) CONFIG_HZ_100=y
(ARMv7 only) CONFIG_SCHED_HRTICK=y

# Timers subsystem
(ARMv7 only) CONFIG_HIGH_RES_TIMERS=y 1

# Debug Lockups and Hangs
(OK) CONFIG_TIMER_STATS=y
(OK) CONFIG_DEBUG_PREEMPT=y

# RCU Debugging
(OK) CONFIG_TREE_PREEMPT_RCU=y
(OK) CONFIG_PREEMPT_RCU=y

If the kernel build a successful, try to make the tests.

Hi Artyom,

the green coloured settings are already enabled, the red coloured settings cannot be enabled due to different reasons:
- they depend on a certain architecture or minimal kernel version
- they depend on additional patches being applied first

Cheers
Uli

You use "make menuconfig" when configuring your kernel? I find some info about (as i undestand minimal kernel configuration):
--------------------------------------------------------------------------------------------
Required parameters for configuring realtime kernel?
Kernel 2.6.x:
CONFIG_PREEMPT=y
CONFIG_PREEMPT_RT=y
Kernel 3.x:
CONFIG_PREEMPT=y
CONFIG_PREEMPT_RT_BASE=y
CONFIG_PREEMPT_RT_FULL=y
Optional parameters for configuring realtime kernel, but they affect realtime performance?
CONFIG_HIGH_RES_TIMERS=y
------------------------------------------------------------------------------------------------------------------
More you can find here: https://rt.wiki.kernel.org/index.php/Fre...nel_3.x:_2

As I undestand CONFIG_PREEMPT_RT_FULL must present in our kernel...

---

@umiddelb
Hi again Uli!

Try to recompile the kernel with these options:

...
# RCU Subsystem
(OK) CONFIG_TREE_PREEMPT_RCU=y
(OK) CONFIG_PREEMPT_RCU=y
...
# Kernel Features
(OK) CONFIG_PREEMPT=y
(OK) CONFIG_PREEMPT_RT_BASE=y
(Not present) CONFIG_HAVE_PREEMPT_LAZY=y
(Not present) CONFIG_PREEMPT_LAZY=y
.....
(Not present) CONFIG_PREEMPT_RT_FULL=y
(OK) CONFIG_PREEMPT_COUNT=y
(ARMv7 only, 3.12+ only)CONFIG_HZ_FIXED=0
(MIPS only) CONFIG_HZ_100=y
(ARMv7 only) CONFIG_SCHED_HRTICK=y

# Timers subsystem
(ARMv7 only) CONFIG_HIGH_RES_TIMERS=y 1

# Debug Lockups and Hangs
(OK) CONFIG_TIMER_STATS=y
(OK) CONFIG_DEBUG_PREEMPT=y

# RCU Debugging
(OK) CONFIG_TREE_PREEMPT_RCU=y
(OK) CONFIG_PREEMPT_RCU=y

If the kernel build a successful, try to make the tests.

Hi Artyom,

the green coloured settings are already enabled, the red coloured settings cannot be enabled due to different reasons:
- they depend on a certain architecture or minimal kernel version
- they depend on additional patches being applied first

Cheers
Uli

You use "make menuconfig" when configuring your kernel? I find some info about (as i undestand minimal kernel configuration):
--------------------------------------------------------------------------------------------
Required parameters for configuring realtime kernel?
Kernel 2.6.x:
CONFIG_PREEMPT=y
CONFIG_PREEMPT_RT=y
Kernel 3.x:
CONFIG_PREEMPT=y
CONFIG_PREEMPT_RT_BASE=y
CONFIG_PREEMPT_RT_FULL=y
Optional parameters for configuring realtime kernel, but they affect realtime performance?
CONFIG_HIGH_RES_TIMERS=y
------------------------------------------------------------------------------------------------------------------
More you can find here: https://rt.wiki.kernel.org/index.php/Fre...nel_3.x:_2

As I undestand CONFIG_PREEMPT_RT_FULL must present in our kernel...

Uli, try to find this in "menuconfig": Preemption Model --> Fully Preemptible Kernel (RT)