For years
the BFQ I/O scheduler has been trying to get in the mainline kernel and it looks like they have an action plan for getting accepted upstream.
BFQ is a proportional-share I/O scheduler that shares a lot of code with the CFQ scheduler. The Completely Fair Queuing (CFQ) scheduler has long been part of the mainline tree but BFQ hasn't been pulled yet even after many revisions and code reviews, as
outlined previously on Phoronix. While it doesn't look like it will be ready for the upcoming Linux 4.2 cycle, it appears BFQ getting accepted is becoming quite close.
Paolo Valente of the BFQ I/O Scheduler project wrote that they have now achieved step one of three for getting accepted. They had to make the block I/O controller ready for generic policies as a prereq for getting merged and on Friday that patch was accepted. Next they need to wipe from the CFQ scheduler all of the code not related to any feature of BFQ. Lastly, they then just need to propose BFQ as a modification of the slimmed down CFQ code.
Details via
this bfq-iosched posting. Hopefully later this year we'll see BFQ in the mainline Linux kernel. Those wishing to read up on the Budget Fair Queuing I/O Scheduler can find all of the details via
the project site.