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From: Con Kolivas <kernel@kolivas.org>
To: linux kernel mailing list <linux-kernel@vger.kernel.org>
Cc: Nick Piggin <piggin@cyberone.com.au>
Subject: Deadline for video capture
Date: Thu, 22 Jan 2004 16:08:00 +1100	[thread overview]
Message-ID: <200401221608.05924.kernel@kolivas.org> (raw)

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Hi all

I suspected that the anticipatory scheduler might not have been the best 
choice for video capture because of the interruption to writes by reads and 
the subsequent anticipatory delay associated with it.  I have now confirmed 
that booting with the default anticipatory i/o elevator I get many dropped 
frames that I don't get if I boot with elevator=deadline. 

briefly: dual 7200 rpm ATA5 IDE drives in software RAID0

I guess there isn't really a lot to do about this, it's a compromise one way 
or the other. The anticipatory scheduler seems better all round but in this 
large streaming write situation it doesn't seem ideal. Any sysctl settings I 
could use to blunt the anticipation just before I do video capture?

Con
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             reply	other threads:[~2004-01-22  5:08 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-01-22  5:08 Con Kolivas [this message]
2004-01-22  5:17 ` Deadline for video capture Nick Piggin
2004-01-22 14:28   ` Timothy Miller
2004-01-22 15:37     ` Con Kolivas

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