[Xenomai-core] [PATCH] detect problematic kernel configs

[Xenomai-core] [PATCH] detect problematic kernel configs

[Jan Kiszka]

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Hi,

this patch tries to reduce the traps newbies may tap by leaving (for us)
well-known problematic kernel switches on. And are there any futher I
forgot, e.g. on other archs?

Jan

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Index: ksrc/arch/i386/Kconfig
===================================================================
--- ksrc/arch/i386/Kconfig	(revision 924)
+++ ksrc/arch/i386/Kconfig	(working copy)
@@ -194,3 +194,19 @@ depends on XENO_OPT_NUCLEUS
 source "drivers/xenomai/Kconfig"
 
 endmenu
+
+if XENOMAI = y
+
+comment "WARNING: Potential latency killers detected!"
+        depends on PM || ACPI || CPU_FREQ
+
+comment "Power Management (PM)"
+        depends on PM
+
+comment "ACPI"
+        depends on ACPI
+
+comment "CPU frequency scaling (CPU_FREQ)"
+        depends on CPU_FREQ
+
+endif


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Re: [Xenomai-core] [PATCH] detect problematic kernel configs

[Gilles Chanteperdrix]

Jan Kiszka wrote:
 > Hi,
 > 
 > this patch tries to reduce the traps newbies may tap by leaving (for us)
 > well-known problematic kernel switches on. And are there any futher I
 > forgot, e.g. on other archs?
 > 
 > Jan
 > Index: ksrc/arch/i386/Kconfig
 > ===================================================================
 > --- ksrc/arch/i386/Kconfig	(revision 924)
 > +++ ksrc/arch/i386/Kconfig	(working copy)
 > @@ -194,3 +194,19 @@ depends on XENO_OPT_NUCLEUS
 >  source "drivers/xenomai/Kconfig"
 >  
 >  endmenu
 > +
 > +if XENOMAI = y
 > +
 > +comment "WARNING: Potential latency killers detected!"
 > +        depends on PM || ACPI || CPU_FREQ
 > +
 > +comment "Power Management (PM)"
 > +        depends on PM
 > +
 > +comment "ACPI"
 > +        depends on ACPI

Only ACPI_PROCESSOR is a latency killer.

-- 


					    Gilles Chanteperdrix.

Re: [Xenomai-core] [PATCH] detect problematic kernel configs

[Jan Kiszka]

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Gilles Chanteperdrix wrote:
> Jan Kiszka wrote:
>  > Hi,
>  > 
>  > this patch tries to reduce the traps newbies may tap by leaving (for us)
>  > well-known problematic kernel switches on. And are there any futher I
>  > forgot, e.g. on other archs?
>  > 
>  > Jan
>  > Index: ksrc/arch/i386/Kconfig
>  > ===================================================================
>  > --- ksrc/arch/i386/Kconfig	(revision 924)
>  > +++ ksrc/arch/i386/Kconfig	(working copy)
>  > @@ -194,3 +194,19 @@ depends on XENO_OPT_NUCLEUS
>  >  source "drivers/xenomai/Kconfig"
>  >  
>  >  endmenu
>  > +
>  > +if XENOMAI = y
>  > +
>  > +comment "WARNING: Potential latency killers detected!"
>  > +        depends on PM || ACPI || CPU_FREQ
>  > +
>  > +comment "Power Management (PM)"
>  > +        depends on PM
>  > +
>  > +comment "ACPI"
>  > +        depends on ACPI
> 
> Only ACPI_PROCESSOR is a latency killer.
> 

Good point. Are there also some more fine-grained switches under
CONFIG_PM? Never tried this in details, always picked the safe way.

Jan


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