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

Horst von Brand (vonbrand@inf.utfsm.cl)
Wed, 05 Sep 2001 10:26:28 -0400


"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
Casilla 110-V, Valparaiso, Chile                Fax:  +56 32 797513
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/