Linux 4.12 has been released
Summary: This release includes a new BFQ I/O scheduler which provides a much better interactive experience; it also includes preliminary support for Radeon RX Vega graphic cards and support for USB Type-C connectors; improvements to the live kernel patching feature, support for Intel IMSM's Partial Parity Log which allows to close the RAID5 write hole; support for exposing OpenChannel SSDs as device blocks, and another I/O scheduler, Kybe that allows to configure a latency target for reads and writes, ,
Preliminary Radeon Vega support
This release adds preliminary support for Radeon RX Vega
Code: merge
USB Type-C support
This release adds support for USB Type-C
Code: commit
New BFQ I/O scheduler for a more reponsive desktop
BFQ (Budget Fair Queuing) is a new I/O scheduler. For personal systems, BFQ provides low latency for interactive applications, low latency for soft real-time applications, higher speed for code-development tasks, high throughput, and strong fairness, bandwidth and delay guarantees. For servers, besides the same benefits as above, BFQ guarantees: audio and video-streaming with zero or very low jitter and drop rate; fast retrieval of WEB pages and embedded objects; real-time recording of data in live-dumping applications (e.g., packet logging); responsiveness in local and remote access to a server. For more details and benchmarks, see the Documentation
Recommended LWN article: Two new block I/O schedulers for 4.12
Code: commit
New Kyber I/O scheduler
The Kyber I/O scheduler is a low-overhead scheduler suitable for multiqueue and other fast devices. Given target latencies for reads and synchronous writes, it will self-tune queue depths to achieve that goal, similary to blk-wbt.
Recommended LWN article: Two new block I/O schedulers for 4.12
Code: commit
Progress in Live kernel patching
Live patching is a feature merged in Linux 4.0
This release adds a so-called per-task consistency model - a foundation which will eventually enable to patch those ~10% of security patches which change function or data semantics. This is the biggest remaining piece needed to make livepatch more generally useful. This code stems from the design proposal
Recommended LWN article: Topics in live kernel patching
Code: commit
Add support for Intel IMSM's Partial Parity Log
This release adds support for the Partial Parity Log feature found in Intel IMSM raid array. This feature is another way to close the RAID 5 Write Hole. PPL is available for md version-1 metadata and external (specifically IMSM) metadata arrays. It can be enabled using mdadm option {{{--consistency-policy=ppl}}}.
Documentation: Documentation/md/raid5-ppl.txt
Code: commit
Expose OpenChannel SSDs as device blocks
This release introduces pblk, a host-side FTL for Open-Channel SSDs to expose them like block devices. Open-Channel SSDs are SSDs that do not include a Flash Translation Layer, support for them was included in Linux 4.4
Documentation: http://lightnvm.io/pblk-tools/
Code: commit