Date: Fri, 18 Aug 2006 09:58:13 -0700 (PDT)
From: Christoph Lameter <clameter@sgi.com>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
cc: manfred@colorfullife.com, ak@muc.de, mpm@selenic.com, marcelo@kvack.org,
       linux-kernel@vger.kernel.org, nickpiggin@yahoo.com.au, ak@suse.de,
       dgc@sgi.com
Subject: Re: [MODSLAB 3/7] A Kmalloc subsystem
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On Fri, 18 Aug 2006, KAMEZAWA Hiroyuki wrote:

> Just a note: with SPARSEMEM, we need more calculation and access to
> mem_section[] table and page structs(mem_map).

Uhh, a regression against DISCONTIG. Could you address that issue?

> > vmalloc_to_addr is certainly slower due to the page table walking. But the 
> > user already is aware of the fact that vmalloc memory is not as fast as
> > direct mapped.

> Considering some code walking through a list of objects scattered over all memory,
> Is virtually-mapped area really slow ?

On most arches it is somewhat slower. IA64 is special in the sense that it 
has virtually mapped kernel memory.
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