Re: PREEMPT_RT : 2.6.16-rt12 and boot : BUG ?

[Ingo Molnar]

* Serge Noiraud <serge.noiraud@xxxxxxxx> wrote:

> Hi,
> 
> 	It now works with all config parameters set to yes on 2.6.16-rt16.
> however, PERCPU_ENOUGH_ROOM is set to 384KB.
> I'm now trying to lower this value of PERCPU_ENOUGH_ROOM.
> With 256K and 2.6.16-rt16 : doesn't work.
> With 320K : OK
> So I need to use 320K for PERCPU_ENOUGH_ROOM to boot correctly.

great detective work! I've increased it to 512K in my tree, to be on the 
safe side. I'm not sure which parameter takes so much per-cpu space.  
There's certainly no problem with your config, this must be something 
caused by the -rt tree. The -rt tree introduces a new per-cpu concept 
(called PER_CPU_LOCKED) which is used in a couple of cases, but it 
shouldnt cause this drastic increase of the per-cpu area's size. Weird.

	Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/