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From: Stan Hoeppner <stan@hardwarefreak.com>
To: Jason Newton <nevion@gmail.com>
Cc: xfs@oss.sgi.com
Subject: Re: realtime section bugs still around
Date: Tue, 31 Jul 2012 18:46:25 -0500	[thread overview]
Message-ID: <50186E51.1020107@hardwarefreak.com> (raw)
In-Reply-To: <CAGou9MgMHbTPebFUDXdyLvrUr4T9wo-geNtaPUft9uUmOaju6Q@mail.gmail.com>

On 7/31/2012 6:01 PM, Jason Newton wrote:

> I'm still interested in finding out why streaming a few hundred MB to disk
> has so much over head in comparison to the calculations I do in userspace,

1.  md eats a lot of cycles at high data rates
2.  ATA overhead
3.  IRQ/MSI overhead
4.  Etc.

All these small bits add up to more than negligible CPU overhead at high
data rates.

-- 
Stan

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  reply	other threads:[~2012-07-31 23:46 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-27  8:14 realtime section bugs still around Jason Newton
2012-07-27  9:56 ` Stan Hoeppner
2012-07-30  3:03 ` Dave Chinner
     [not found]   ` <CAGou9MheeBWxajd65szNfDB2L+VVoZ7SypEdUKj7np3L0H8fHA@mail.gmail.com>
2012-07-31 23:01     ` Jason Newton
2012-07-31 23:46       ` Stan Hoeppner [this message]
     [not found]         ` <CAGou9MhneejOuhX4c8G06c3Zh7dxF-OtZ+=mT-7fho_u1Q3zWw@mail.gmail.com>
2012-08-01  3:55           ` Stan Hoeppner
2012-08-01  5:55             ` Jason Newton
2012-08-02  0:39               ` Stan Hoeppner
2012-08-02  2:38                 ` Jason Newton
2012-08-02 10:39                   ` Stan Hoeppner
2012-08-03 11:28                     ` Stan Hoeppner

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