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Date: Sun, 22 Feb 2009 23:20:55 +0100 (CET)
From: Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl>
To: Junsuk Shin <junsukshin@gmail.com>
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Cc: freebsd-questions@freebsd.org
Subject: Re: read two files simultaneously
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> That's true. Using bigger buffer will help, but it doesn't tell why reading
> large size file is slower than reading small size file.
>
really slower? or just bigger difference with large files?


>
> On Sat, Feb 21, 2009 at 5:56 PM, Wojciech Puchar <
> wojtek@wojtek.tensor.gdynia.pl> wrote:
>
>> I'm just guessing inode structure, the physical file location on HDD
>>> might be related to this. But, if I read only one file, the size
>>> doesn't matter. Reading file (10M, 100M, 700M) gives constantly about
>>> 70MB/s, and the weird thing happens when I read 2 files of big size.
>>>
>>
>> if you use O_DIRECT it's read from disk exactly as you specified, without
>> readahead, so you do a lot of seeks.
>>
>> simply use bigger buffer like 1MB
>>
>
>
>
> -- 
> Junsuk
>