High interrupt CPU usage in top

[Matthew Dillon]

:Well, world and kernel just finished compiling, without INVARIANTS, and 
:there's no difference. Infact, it seems worse... but it's probably the 
:same. I guess I should keep INVARIANTS in for debugging in case of panics?
:
:http://img198.imageshack.us/img198/1571/interrupt3eg.jpg
:
:40% and very few interrupts? That was just starting out compiling 
:`mysql4-server`.

    INVARIANTS is pretty light weight, it won't make much of a difference.

    Try doing some basic tests to exercise JUST the network adapter, like
    running a 'ping -i 0.1 <target>'.  And some tests to exercise JUST your
    hard disk, like doing a few cpdup's or a tar or something.

    If its the disk, check your dmesg output to whether the ATA driver is
    using DMA or not.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>