Re: lilo vs other OS bootloaders was: FreeBSD makes progress

[Horst von Brand <vonbrand@inf.utfsm.cl>]

"Grover, Andrew" <andrew.grover@intel.com> said:

[...]

> Here's Linux:
> 
> Drivers (SMP agnostic)

The SMP/UP difference is pervasive in Linux, I don't think there is a
single SMP-agnostic driver (as far as _binaries_ go). Source is mostly
SMP-agnostic.

> Kernel (SMP/UP specific)
> 
> Here's Windows:
> 
> Drivers (SMP agnostic)
> Kernel (SMP agnostic)
> HAL (SMP/UP specific, contains locking primitive funcs etc.)
> 
> So they use the same kernel and just switch out the HAL.

And each SMP/UP aware operation _has_ to be a separate function (no inlines
allowed this way). Doable with not too much overhead, AFAICS (at least in
principle); but maintaining (and synchronizing) a clean split will soon be
a nightmare. Or end up in two separate kernels anyway ;-)

[...]

> For one thing, it would get rid of the hundreds of "#ifdef CONFIG_SMP"s in
> the kernel. ;-)

At least the #ifdef's isolate just the places that must be different in
both cases. It might be worthwhile to abstract them out from the source
(not necesarily from the binary kernel).
-- 
Dr. Horst H. von Brand                Usuario #22616 counter.li.org
Departamento de Informatica                     Fono: +56 32 654431
Universidad Tecnica Federico Santa Maria              +56 32 654239
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