new x86 flavours: -bigmem | -lowlat?

[maximilian attems <maks@sternwelten.at>]

hello guys,

now that the smp alternatives patch went in,
time to think about usefull flavours:

-bigmem got requested several times with CONFIG_HIGHMEM64G=y and
        CONFIG_X86_PAE=y
	added it for now in the d-k repository for 686.
	there is a pending request for xen too.
	also k7 .config will be added

-lowlat with CONFIG_PREEMPT=y and CONFIG_HZ=1000 seems more controversial
	although i could imagine plenty of happy user of it.
	we might just add in the desc "may trigger strange bugs".
	the positive flip side is lots of less skips on
	multimedia apps like lastfm, totem, ..
	last but not least preempt is supported upstream and set in
	default config.

	a more radical approach would be to soak -rt in,
	although i'm not sure if that is release ready.

happy to hear your thoughts.

-- 
maks