The MIPS 34K is the latest member of MIPS's family of MIPS32 processors. It is the first MIPS processor supporting multithreaded execution according to the MT ASE specification.
Linux implements several code models based on the MT ASE which can be choosen at kernel configuration time:
or Virtual SMP uses the processor's VPEs to implement virtual processors. In currently available configuration of the 34K processor this allows for a dual processor. Both processors will share the same primary caches, each will obtain the half of the TLB for it's own exclusive use. For a layman this model can be described as similar to what Intel calls Hyperthreading.
is presenting the available TC's of the core as processors to Linux. On currently available 34K processors this means a Linux system will see up to 5 processors. The implementation of the SMTC kernel differs significantly from VSMP.
is based on a normal Linux uniprocessor kernel. Instead of presenting additional VPEs as processors to the kernel it allows loading of an application program built with MIPS SDE into kernel space where this application will run on a secondary VPE undisturbed by the Linux kernel.
Support for all three code models is available in 34k-2.6.16* branches of linux-mips.org's git repository and will be part of 2.6.17.