What's new in the Linux kernel

and what's missing in Debian

Professional software engineer by day, Debian developer by night
Regular Linux contributor in both roles since 2008
Maintaining a net driver in my day job, plus core networking and PCI code as necessary
Debian kernel team member, now doing most of the unstable maintenance aside from ports
Maintaining Linux 3.2.y stable update series on kernel.org

Linux is released about 5 times a year (plus stable updates every week or two)
- ...though some features aren't ready to use when they firat appear in a release
For 'wheezy' we chose to freeze with Linux 3.2, which was getting pretty old by the time of release
Good news: we have lots of new kernel features in testing/unstable
Bad news: some of them won't really work without new userland

Alternative to the bonding driver - simpler, modular, high-level control deferred to userland
Basic configuration can be done with ip, but it really needs new tools - teamd, teamnl, etc.
Make it work: see http://bugs.debian.org/695850

Abstract storage for memory pages, expected to be slower than regular memory but faster than disk
Can provide a second layer of page cache (cleancache and frontswap)
Pages stored by hypervisor (Xen), compressed local memory (zcache) or cluster of machines (RAMster)
Not yet enabled in Debian kernels, and needs some thought about configuration
Make it work: see https://lwn.net/Articles/454795/ and send proposal to debian-kernel

DRM/KMS drivers added for old, new and virtual hardware - AST, DisplayLink, Hyper-V, Matrox G200, QEMU Cirrus
Should be more robust than purely user-mode drivers, and compatible with Secure Boot
Current X drivers don't work with these, so the kernel drivers are disabled for now
Make it work: join the X Strike Force and package the new X drivers

Kernel modules can be signed at build time, and the kernel configured to refuse loading unsigned modules
Necessary but not sufficient to implement Secure Boot - we would also need signed kernel images and some other restrictions when booted in this mode
Make Secure Boot work: come to the meeting on Tuesday

Flash devices (and thin-provisioned SANs) can be more efficient if the filesystem 'discards' unused disk space
Requires support in hardware, driver, filesystem and any layered device drivers - e.g. LVM, RAID (added in 3.7)
Must be explicitly enabled, but d-i doesn't do this by default
Make it work: fix http://bugs.debian.org/690977

Containers are lightweight VMs - run on the same kernel as host, but with limited privileges and resources
Previously done by OpenVZ and Linux-VServer; gradually being reimplemented upstream
User namespaces (added in 3.7) support the existence of a root user inside the container that is unprivileged outside the container
Currently somewhat experimental, and requires filesystem changes which haven't been done for XFS
Make user namespaces work: send patches to upstream XFS developers (this one's hard)

Turns a fast block device into a cache for a larger, slower device (see also: dm-cache, EnhanceIO)
Needs its own set of userland tools
Make it work: see http://bugs.debian.org/708132 (maybe just needs a sponsor)

Until recently, each ARM kernel image could support only a small set of different chips
Debian 'armmp' kernel now supports ARMv7 SoCs from Calxeda, Freescale and Marvell, and others should be supported soon
Debian could run on a much larger range of ARM hardware - but we need installer and boot loader support to make this easy
Make it work: join the ARM porters and d-i team
Make the GPUs work: join a reverse-engineering project