Deadline for video capture

From: Con Kolivas
Date: Thu Jan 22 2004 - 00:08:59 EST


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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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