Re: [patch 3/7] x86 PAT: hooks in generic vm code to help archs to track pfnmap regions - v3

Pallipadi, Venkatesh
2008-12-18T22:23:53Z

On Thu, Dec 18, 2008 at 01:35:57PM -0800, Nick Piggin wrote:
> On Thu, Dec 18, 2008 at 11:41:29AM -0800, venkatesh.pallipadi@intel.com wrote:
> > Introduce generic hooks in remap_pfn_range and vm_insert_pfn and
> > corresponding copy and free routines with reserve and free tracking.
>
> These should be inline so that they can be folded out (I'm sure gcc
> with -Os and "optimize" inlining will do something stupid here).
> Also, the normal way to add such arch hooks is to put the default
> into asm-generic and have other archs include it... that would be
> nicer than sticking it into mm/memory.c wouldn't it?

I did check that these calls were optimized by gcc when there is no arch
specific definitions. But, as you pointed out, it should be cleaner to put this
in asm-generic, though I may have to touch more files.

> Sigh, fork/exit paths slow down yet again. But oh well. Maybe can
> you add some branch hints?

OK. Will add branch hints for these..

Thanks,
Venki