[$] What became of getrandom() in the vDSO

Post Syndicated from corbet original https://lwn.net/Articles/983186/

In the previous episode of the
vgetrandom() story, Jason Donenfeld had put together a version of
the getrandom()
system call that ran in user space, significantly improving performance for
applications that need a lot of random data while retaining all of the
guarantees provided by the system call. At that time, it seemed that a
consensus had built around the implementation and that it was headed toward
the mainline in that form. A few milliseconds after that article was
posted, though, a Linus-Torvalds-shaped obstacle appeared in its path.
That obstacle has been overcome and this work has now been merged for the
6.11 kernel, but its form has changed somewhat.