3.14 Merge window part 3

Interesting user-visible changes found in the 2000 patches pulled since last week's summary include:

• The zram compressed swap subsystem (described in this article from 2013) has been moved out of the staging tree and into the core memory management code. Minchan Kim's commit notes that zram is now used heavily in television sets; recent Android handsets have started using it as well.

• Support for user mode-setting in the Intel i915 driver has been deprecated, in preparation for removing it entirely roughly one year from now. Anybody who depends on this mode would do well to make their needs known in that time.

• The Btrfs filesystem now provides much more information via sysfs, including supported features, space utilization data, and more. Much of this information is available via ioctl(), but sysfs interfaces can be easier to use in scripts or from the command line.

• New hardware support includes:
  • Systems and processors: MIPS interAptiv processors.

  • Miscellaneous: ITE IT8603E hardware monitoring chips, Intel BayTrail IOSF-SB mailbox interface controllers, Broadcom BCM281xx watchdogs, Broadcom BCM2835 DMA controllers, MOXA ART SoC DMA controllers, and watchdogs controlled over GPIO lines.

  • Networking: RealTek RTL8821AE Wireless LAN NICs.

  • Video4Linux: TI OMAP4 camera controllers, Broadcom BCM2048 FM radio receivers, Silicon Labs Si4713 FM radio transmitters, Thanko Raremono AM/FM/SW radios, Montage M88DS3103 DVB-S/S2 demodulators, Montage M88TS2022 silicon tuners, and Samsung S5K5BAF camera sensors.

Changes visible to kernel developers include:

• The "immutable biovec" patch set has been merged; it introduces some significant API changes to the block layer, but it enables the creation of arbitrarily large I/O requests and improves efficiency. See Documentation/block/biovecs.txt for more information.

One final feature that might yet make it into 3.14 is the proposed renameat2() system call, which Linus wanted to review more deeply before committing to. That code might get pulled before 3.14-rc2, but, Linus said, "quite frankly it's more likely to be left pending for 3.15". Other than that, the feature set for the 3.14 kernel should be complete at this time. If the usual schedule holds, this kernel can be expected sometime toward the end of March.