Date: Sun, 22 Feb 2009 13:44:18 -0500 From: Junsuk Shin <junsukshin@gmail.com> To: Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl>, freebsd-questions@freebsd.org Subject: Re: read two files simultaneously Message-ID: <7873ac110902221044hfd96a8cn5b32e0f90edca212@mail.gmail.com> In-Reply-To: <20090221235530.C60480@wojtek.tensor.gdynia.pl> References: <7873ac110902211146k6a8ee7d0pd67edc559ed14b15@mail.gmail.com> <20090221235530.C60480@wojtek.tensor.gdynia.pl>
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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. 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
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