Read-Copy-Update has been around for quite some time, but the fact that it was patent encumbered meant that its usage was limited. IBM made the patent availabl

Read-Copy-Update has been around for quite some time, but the fact that it was patent encumbered meant that its usage was limited. IBM made the patent available for use in the Linux kernel, and now that it is expired, the technique is being made available more widely to applications in userspace. This is just one of many possible approaches to making data structures more scalable through clever use of memory ordering.