Re: Populating multiple ptes at fault time

From: MinChan Kim
Date: Thu Sep 18 2008 - 19:16:54 EST


On Fri, Sep 19, 2008 at 7:23 AM, Chris Snook <csnook@xxxxxxxxxx> 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
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