Re: [PAE support] patch review

[Paul Goyette <paul%whooppee.com@localhost>]

On Sat, 17 Jul 2010, Jean-Yves Migeon wrote:

> - introduce i386_cpu_switch_pmap(), used to switch pmap for the curcpu.
> Due to the different handling of pmap mappings with PAE vs !PAE, Xen vs
> native, I hid the details within this function. This helps calling it
> from assembly, as some features, like BIOS calls, switch to pmap_kernel
> before mapping trampoline code in low memory.
>
> WARNING: this function currently *breaks* the amd64 build (obviously,
> there is no i386_cpu_switch_pmap() for amd64).
>
> ==> this part will be re-written with a cleaner abstraction, in sync
> with rmind and his uvmplock branch. But I would like you to review the
> rest of the patch.

You will fix the breakage before committing, right?

With this impact, should this discussion also include the port-amd64 
list?


> Two questions:
> - is it ok for everyone to add PAE to ALL kernel? This can raise paddr_t
> issues within drivers, as well as some format string errors.

I think you should add it - better to find the issues now, and get them 
resolved, rather than finding them later.

> - should I add a "#options PAE" within GENERIC config file, or provide
> additional GENERIC_PAE/MONOLITHIC_PAE files?

I would prefer not to create more config files.  A

        #options PAE

should be fine.


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