Re: 2.5.38-mm2 dbench $N times

Martin J. Bligh
2002-09-25T06:00:34Z

>> Not sure. This is boot bay SCSI crud, but single-disk FC looks
>> *worse* for no obvious reason. Multiple disk tests do much better
>> (about matching the el-scruffo PC numbers above).
>
> dbench 16 on that sort of machine is a memory bandwidth test.
> And a dcache lock exerciser. It basically doesn't touch the
> disk. Something very bad is happening.

Does dbench have any sort of CPU locality between who read it
into pagecache, and who read it out again? If not, you stand
7/8 chance of being on the wrong node, and getting 1/20 of the
mem bandwidth ....

M.