ATA_CAM + ZFS gives short 1-2 seconds system freeze on disk load

[Ivan Voras]

On 02/08/10 15:33, Guido Falsi wrote:

> It looks like it freezes the system for the second or two it takes
> to flush buffers to disk when there are big outputs. This happens
> when decompressiong big distfiles, mainly. The openoffice port
> triggers this almost continuosly every few seconds during compilation.
> I've also seen this when working with big files(for example graphic
> images in uncompressed formats).
>
> It gets very annoying and I don't remember this happening before
> activating the ATA_CAM flag. There was some slowdown with big disk
> access, but not a total freeze.

I think ZFS does this all the time, i.e. regardless of underlying device 
drivers. Can you test your theory by going to an older kernel and 
keeping *everything* else the same?