Re: [PATCH 0/7] Sparsemem Virtual Memmap V5

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 13 Jul 2007 10:04:45 -0700 (PDT) Christoph Lameter <clameter@sgi.com> wrote:

> On Fri, 13 Jul 2007, Andy Whitcroft wrote:
> 
> > Andrew, please consider for -mm.
> > 
> > Note that I am away from my keyboard all of next week, but I figured
> > it better to get this out for testing.
> 
> Yes grumble. Why does it take so long...

gaah, I read linux-arch and linux-mm rather intermittently and I haven't
even seen these yet.

> Would it be possible to merge this for 2.6.23 (maybe late?).

It would be nice to see a bit of spirited reviewing from the affected arch
maintainers and mm people...

There's already an enormous amount of mm stuff banked up and it looks like
I get to hold onto a lot of that until 2.6.24.  We seem to be spending too
little time on the first 90% of new stuff and too little time on the last
10% of existing stuff.


> This has been 
> around for 6 months now. It removes the troubling lookups in 
> virt_to_page and page_address in sparsemem that have spooked many of us. 
> 
> virt_to_page efficiency is a performance issue for kfree and 
> kmem_cache_free in the slab allocators. I inserted probles and saw 
> that the patchset cuts down the cycles spend in virt_to_page by 50%.