Re: PREEMPT_RT vs ADEOS: the numbers, part 1

[Ingo Molnar <mingo@elte.hu>]

* Karim Yaghmour <karim@opersys.com> wrote:

> Here's the .config for 2.6.12-rc4-RT-V0.7.47-08:

Thanks. These PREEMPT_RT debugging features should be disabled:

> CONFIG_DEBUG_PREEMPT=y
> CONFIG_WAKEUP_TIMING=y
> CONFIG_PREEMPT_TRACE=y
> CONFIG_LATENCY_TIMING=y
> CONFIG_RT_DEADLOCK_DETECT=y

they all cause significant overhead.

I'd also disable these two security options:

> CONFIG_AUDIT=y
> CONFIG_SECURITY=y

unless you are running an selinux-enabled environment.

i've had not that good experiences with HPET:

> CONFIG_HPET_TIMER=y
> CONFIG_HPET_EMULATE_RTC=y

so i'd disable it - but YMMV.

i'd also disable PAE and use CONFIG_NOHIGHMEM:

> CONFIG_HIGHMEM64G=y

unless you have more than 4GB of RAM. (if you have between 1GB and 4GB 
then use HIGHMEM4G)

then i'd disable stack-overflow checking as well:

> CONFIG_DEBUG_STACKOVERFLOW=y
> CONFIG_DEBUG_STACK_USAGE=y

since you are not running 4K stacks.

	Ingo