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Message-ID: <28c262360809181616p481f9126p50c9a8c971fbbf9e@mail.gmail.com>
Date: Fri, 19 Sep 2008 08:16:43 +0900
From: "MinChan Kim" <minchan.kim@gmail.com>
To: "Chris Snook" <csnook@redhat.com>
Subject: Re: Populating multiple ptes at fault time
Cc: "Christoph Lameter" <cl@linux-foundation.org>,
       "Martin Bligh" <mbligh@google.com>,
       "Jeremy Fitzhardinge" <jeremy@goop.org>,
       "Nick Piggin" <nickpiggin@yahoo.com.au>,
       "Hugh Dickens" <hugh@veritas.com>,
       "Linux Memory Management List" <linux-mm@kvack.org>,
       "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
       "Avi Kivity" <avi@qumranet.com>,
       "Andrew Morton" <akpm@linux-foundation.org>,
       "Rik van Riel" <riel@redhat.com>
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On Fri, Sep 19, 2008 at 7:23 AM, Chris Snook <csnook@redhat.com> wrote:
> Christoph Lameter wrote:
>>
>> Martin Bligh wrote:
>>>>
>>>> My patches were only for anonymous pages not for file backed because
>>>> readahead
>>>> is available for file backed mappings.
>>>
>>> Do we populate the PTEs though? I didn't think that was batched, but I
>>> might well be wrong.
>>
>> We do not populate the PTEs and AFAICT PTE population was assumed not to
>> be
>> performance critical since the backing media is comparatively slow.
>>
>
> Perhaps we should.  In a virtual guest, the backing media is often an
> emulated IDE device, or something similarly inefficient, such that the
> bottleneck is the CPU.

In embedded environment, many people use nand-like device as storage.
Read cost of nand-like device is less than IDE's one.
Also, Nowaday Embedded stuff would like to use multi-core step by step.
So, pte population become important more and more.


> -- Chris
>



-- 
Kinds regards,
MinChan Kim