Re: Debian hyperthreading support
On 10/2/2010 6:08 PM, Nathen wrote:
Pretty simple question really, does Debian i.e. the current Linux
Kernel handle hyperthreading well? I have a server running on an Intel
Atom D510, should I have HT enabled or disabled to get the best
Recently (kernel 2.6.31 or so) there has been a separate kernel
configuration option to optimize for SMT (Intel's word for it is
"hyperthreading"). Separate from SMP (multiple processor). Under SMT,
a single core running two threads looks like two cores to most of the
kernel itself and to user programs. This has been true for a long time.
Only now, there is more support and optimization for it. If your
kernel has it enabled, some workloads won't see any difference, but some
will benefit a lot. I think it is enabled by default in the most recent
stock kernels (please correct me if I'm wrong.)
Note, you may need to enable hyperthreading in your BIOS, as well.
I would enable it for Core i7 and Atom. P4-era machines could sometimes
have software compatibility issues with it enabled, but I think Debian
and Atoms are good.