3.4 Merge window part 2

In the 3.3 release announcement, Linus warned developers that he would be taking a bit of time off during the merge window; that did indeed happen over the last week. Still, he managed to pull some 4,000 changesets since last week's summary. Some of the more significant changes merged in the last week include:

• The PowerPC has gained a new firmware-assisted dump facility for the quick capture and analysis of crash dumps.

• The GFS2 filesystem now supports the FITRIM ioctl() command which can be used to send discard requests to the underlying storage device.

• The prctl() system call has a new option called PR_SET_CHILD_SUBREAPER. Marking a process this way will cause any orphan descendant processes to be reparented to the marked process rather than to the init process. There is a corresponding PR_GET_CHILD_SUBREAPER option as well.

• The Microblaze architecture now has high memory support.

• The ext4 "noacl" and "noattr" mount options have been marked deprecated with an eye toward removal in the near future. Without these options, it will not be possible to disable ACL and extended attribute support. No other filesystem allows that support to be disabled. The "journal=update" and "resize" mount options have been removed entirely. On the other hand, plans to remove the "bsd_df", "minix_df", "grpid" and "nogrpid" options have been dropped in response to complaints from users.

• New hardware support includes:
  • Processors and systems: GE Intelligent Platforms IMP3A boards, Atmel AT91SAM9x5 processors, Bluegiga APX4 development kits, and OMAP4 "remote" processors (see below).

  • Audio: Wolfson WM2200 CODECs, and Maxim MAX9768 amplifiers.

  • Graphics: Intel Medfield-based GMA500 adapters, NVIDIA Kepler chipsets (mode-setting only), ATI RadeonHD 7xxx and "Trinity" chipsets, USB-attached Displaylink video adapters, Samsung S5PC210 and EXYNOS MIPI-DSI controllers, and Intel 750 graphics cards.

  • Input: Cypress TrueTouch Standard Product touchscreen controllers, Synaptics USB touchpads, TI touchscreen controllers, MAXIM MAX8997 haptic controllers, and Ilitek ILI210X based touchscreens.

  • Miscellaneous: Freescale IFC external NAND controllers, NVIDIA Tegra pinmuxes, CSR SiRFprimaII-based I2C interfaces, TI LP8550/LP8551/LP8552/LP8553/LP8556 backlight devices, Pandora console backlight devices, and Dialog DA9052/DA9053 RTCs.

    Video4Linux: Afatech AF9005 based DVB-T/DVB-C receivers, and Keene FM transmitters.

Changes visible to kernel developers include:

• A new subsystem called "remoteproc" has been merged; it allows for the control of remote processors (those on the same SoC but running something other than Linux) through shared memory. The new "rpmsg" subsystem is a virtio-based mechanism for communicating with those processors. There will probably be a separate article on these facilities soon; in the meantime, see Documentation/remoteproc.txt and rpmsg.txt for more information.

• The new for_each_clear_bit() macro iterates through each un-set bit in a word.

• The poll_requested_events() function has been added as a way for drivers to learn exactly what events user space is polling for. Also added is:

      bool poll_does_not_wait(const poll_table *p);
  

  which returns true iff it is known that the poll() call will not block.

Also worthy of note is that there has been a vast amount of work done in the ARM architecture tree; the process of consolidating and cleaning up the ARM code continues at a high rate.

The 3.4 merge window would normally be expected to end around April 2. When he announced his vacation, Linus said that he would extend the merge window for a bit if necessary - though he warned that he would still only consider pull requests received during the window. Whether that will happen remains to be seen; either way, next week's Kernel Page will summarize the last new features merged for 3.4.

Index entries for this article
Kernel	Releases/3.4

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