[$] Heterogeneous memory management meets EXPORT_SYMBOL_GPL()

Post Syndicated from corbet original https://lwn.net/Articles/757124/rss

One of the many longstanding — though unwritten — rules of kernel
development is that infrastructure is not merged until at least one user
for that infrastructure exists. That helps developers evaluate potential
interfaces and be sure that the proposed addition is truly needed. A big
exception to this rule was made when the heterogeneous memory management
(HMM) code was merged, though. One of the reasons for the lack of users in
this case turns out to be that many of the use cases are proprietary; that
has led to some disagreements over the GPL-only status of an exported
kernel symbol.