#10045 HIGH 1.5-sof: XO-1.5 Record audio/video are out of sync with each other
quozl at laptop.org
Tue May 11 22:41:34 EDT 2010
On Tue, May 11, 2010 at 10:16:13PM -0400, Martin Langhoff wrote:
> What you are saying is that this is a different issue from what dsd
> tracked down -- entirely possible that these are 2 orthogonal issues.
Yes, entirely possible.
> Does the frequency and/or std deviation change if you tweak the
> vm.dirty_* sysctl values?
Yes, significantly. What I've observed is most likely entirely due to
The default on os123 is
Changing this to
causes the dd to finish in 7 seconds instead of 92 seconds, the sync to
take much longer, and the write latencies are much smaller.
So the effect I was seeing was documented ... "process which is
generating disk writes will itself start writing out dirty data.", per
vm.txt in Documentation/
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