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To: Daniel Phillips <phillips@bonn-fries.net>
Cc: Oliver Xymoron <oxymoron@waste.org>,
        Linus Torvalds <torvalds@transmeta.com>,
        Rik van Riel <riel@conectiva.com.br>,
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Subject: Re: Note describing poor dcache utilization under high memory pressure
In-Reply-To: <Pine.LNX.4.44.0201281918050.18405-100000@waste.org>
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From: Momchil Velikov <velco@fadata.bg>
Date: 29 Jan 2002 11:20:13 +0200
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>>>>> "Daniel" == Daniel Phillips <phillips@bonn-fries.net> writes:

Daniel> On January 29, 2002 09:39 am, Momchil Velikov wrote:
>> >>>>> "Oliver" == Oliver Xymoron <oxymoron@waste.org> writes:
Oliver> you can't actually _share_ the page tables without marking the pages
Oliver> themselves readonly.
>> 
>> Of course, ptes are made COW, just like now. Which brings up the
>> question how much speedup we'll gain with a code that touches every
>> single pte anyway ?

Daniel> It's only touching the ptes on tables that are actually used, so if a parent
Daniel> with a massive amount of mapped memory forks a child that only instantiates
Daniel> a small portion of it (common situation) then the saving is pretty big.

Umm, all the ptes af the parent ought to be made COW, no ?

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