Lot more swapping in stable/10 with ZFS

[Nagy, Attila]

Hi,

Running stable/10 at r261157 (and earlier too), I've noticed that it swaps 
much more than previous (stable/9) versions.
Current top output from such a machine:
Mem: 251M Active, 21M Inact, 7491M Wired, 118M Cache, 17M Buf, 51M Free
ARC: 5112M Total, 1455M MFU, 2155M MRU, 7761K Anon, 293M Header, 1223M Other
Swap: 2045M Total, 757M Used, 1287M Free, 37% Inuse, 1280K Out

(there are frequent ins too, so I wouldn't say that the kernel just 
throws unused pages out)
Why ZFS keeps its cache instead of releasing it and free up memory to 
avoid swapping?

Is there a better way to change this than lowering ARC's maximum usage?

All *swap* sysctl values are the same as on 9 versions. Is this 
something changed in the VM handling or in ZFS?

Thanks,