Patent problem for a future Linux feature?
A report from LWN.net suggests that there may be a patent problem with KSM, a memory management technology that is a candidate for inclusion in a future version of Linux. KSM attempts to extend the idea of sharing memory pages between processes from just managing shared libraries, to any identical memory pages, such as running multiple copies of the same program, or virtualised guest operating systems.
The problem is that there appears to be a software patent held by VMware which seems to, at least in abstract, cover the operation of KSM. The patent, filed in 2001 and granted in 2004, still needs to be evaluated in detail, especially in the light of potential prior art in a previously abandoned Linux feature from 1998, called Mergemem.
LWN suggests that, even if the patent is valid, given that VMware is a member of the Linux Foundation, it may be possible to broker some agreement on the patent. KSM still has much development work to be done, especially on security issues, where it is believed there may be a possibility of information leakage.