On Mon, Sep 29, 2003 at 01:10:37PM +0200, Ulrich Rhein wrote: > Thomas Eastman <[EMAIL PROTECTED]> writes: > > > 3. What's the deal with Hyperthreading? Am I going to need to set up an SMP > > kernel? Is there anything else that is important to know about configuring a > > Hyperthreading CPU? > > For the software, a HT CPU is equivalent to two CPUs: It has two machine > contexts, that means two decoders and two register files. As the > Pentium4 has a very long pipeline, mispredicted jumps stall the whole > unit for a long period. When this happens, a HT P4 simply executes the > instructions on the other thread, while a non-HT P4 wouldn't do anything > (except refilling the pipeline).
There has also been some interesting discussion of how hyperthreading interacts with Linux clustering software -- like openmosix. There are some specific commands in openmosix to keep it from being fooled that there are two CPU's present in a single CPU box, I saw in some of the documentation. I'm just beginning to play with it, so my knowledge is weak. It's probably not an issue at all for someone not setting up a cluster. -- Nate Duehr <[EMAIL PROTECTED]> -- [EMAIL PROTECTED] mailing list
