Linux_2_6_20 - Linux Kernel Newbies

Short overview (for news sites, etc)

2.6.20 adds hardware virtualization support through KVM (http://kvm.sourceforge.net), paravirtualization support that will be used by Xen/Vmware etc, initial Sony Playstation 3 support, a fault injection debugging feature, UDP-lite support, better per-process IO accounting, relative atime, support for using swap files for suspend, relocatable x86 kernel support for kdump users, small microoptimizations in x86 (sleazy FPU, regparm, support for the Processor Data Area, optimizations for the Core 2 platform), Generic HID layer, DEEPNAP power savings for PPC970

Important things (AKA: ''the cool stuff'')

Sony Playstation 3 support

Virtualization support through KVM

KVM ([http://kvm.sourceforge.net project page]) adds a driver for Intel's and AMD's hardware virtualization extensions to the x86 architecture (KVM will not work in CPUs without virtualization capabilities).

The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation.

32 and 64 bits guests are supported (but not x86-64 guests on x86-32 hosts!). For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported, SMP guests aren't (support will be added in the future). You also can start multiple virtual machines in a host. Performance currently is non-stellar, it will be improved by a lot with the future inclusion of [http://lkml.org/lkml/2007/1/5/205 KVM paravirtualization].

The Windows install currently bluescreens due to a problem with the virtual APIC, a fix is being worked on and will be added in future releases. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work either.

[http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7 (commit)]

Paravirtualization support for i386

Relocatable kernel support for x86

This feature (enabled with CONFIG_RELOCATABLE) isn't very noticeable for end-users but it's quite interesting from a kernel POV. Until now, it was a requeriment that a i386 kernel was loaded at a fixed memory address in order to work, loading it in a different place wouldn't work. This feature allows to compile a kernel that can be loaded at different 4K-aligned addresses, but always below 1 GB, with no runtime overhead. Kdump users (a feature introduced in [http://kernelnewbies.org/Linux_2_6_13 2.6.13] that it triggers [http://lwn.net/Articles/108595/ kexec] in a kernel crash in order to boot a kernel that has been previously loaded at a 'empty' address, then runs that kernel, saves the memory where the crashed kernel was placed, dumps it in a file and continues booting the system) will benefit from this because until now the "rescue kernel" need to be compiled with different configuration options in order to make it bootable at a different address. With a relocatable kernel, the same kernel can be boot at different addresses. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=968de4f02621db35b8ae5239c8cfc6664fb872d8 (commit 1], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e69f202d0a1419219198566e1c22218a5c71a9a6 2], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=be274eeaf20b4c7155242645d5e2c48b023e609b 3], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=fd593d12770d4a0d1ff095d44b96436c18479ee8 4)]

Use 'regparm' in x86-32

This is another not-relevant-to-users-yet-interesting-for-geeks feature, that has been available as an option for a while but it's default now. Since forever the x86 architecture has stored the function parameters in the stack. Modern architectures (PPC, SPARC, etc) use registers: It's much faster, since you don't need to do anything to bring the paramaters back: The parameters are just there, in the register. The x86 world continued using stacks for parameter passing, for compatibility reasons with software, compilers, etc; they only added extensions to compilers to optionally tell the compiler to use parameters for parameter pasing in a given function (usually involving the 'fastcall' keyword) for performance-critical paths. Thanks to a GCC extension, the linux kernel uses the '-mregparm=3' compile option, which means that as long as a function uses 3 or less arguments, GCC will automatically use registers to pass its parameters. And if you're wondering about x86-64, in that platforms using the registers has always been the default [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a1a70c25bed75ed36ed48bbe18b9029428d2452d (commit)]

Sleazy FPU optimization

This is a x86-32 port of the x86-64 feature implemented in [http://kernelnewbies.org/Linux_2_6_19 2.6.19]. It doesn't gives huge performance except a very small improvement in FPU-intensive programs, but it's also a interesting optimization. Right now the kernel has a 100% lazy fpu behavior: after *every* context switch a trap is taken for the first FPU use to restore the FPU context lazily. This is of course great for applications that have very sporadic or no FPU use (since then you avoid doing the expensive save/restore all the time). However for very frequent FPU users you take an extra trap every context switch. This feature adds a simple heuristic to this code: After 5 consecutive context switches of FPU use, the lazy behavior is disabled and the context gets restored every context switch. If the app indeed uses the FPU, the trap is avoided (the chance of the 6th time slice using FPU after the previous 5 having done so are quite high obviously). After 256 switches, this is reset and lazy behavior is returned (until there are 5 consecutive ones again). The reason for this is to give apps that do longer bursts of FPU use still the lazy behavior back after some time. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=acc207616a91a413a50fdd8847a747c4a7324167 (commit)]

round_jiffies() infrastructure

Introduce the round_jiffies()/round_jiffies_relative() functions. These functions round a jiffies value to the next whole second. The target of this rounding is all the "we don't care exactly when" timers. By rounding these timers to whole seconds, all such timers will fire at the same time, rather than at various times spread out; with dynamic ticks these extra timers cause wakeups from deep sleep CPU sleep states and thus waste power [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=4c36a5dec25fb344ad76b11860da3a8b50bd1248 (commit 1], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=44d306e1508fef6fa7a6eb15a1aba86ef68389a6 2], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=2b2842146cb4105877c2be51d3857ec61ebd4ff9 3)]

Fault injection

IO Accounting

Relative atime support

'Atime' is the 'Access time' field of a file: When a process reads a file, its atime is updated. Disabling atime updates, with the 'noatime' mount flag, is probably the most used performance tweak that linux administrators use: An active server is continually reading files, generating lots of atime updates, which translate to metadata updates that the filesystem must write to disk. And writing those updates can seriously damage your performance. Believe it or not, a busy server like kernel.org (vsftpd + apache workload) cut their load average in half just by mounting their filesystems with 'noatime'.

Relative atime ('relatime') only updates the atime if the previous atime is older than the mtime or ctime. It avoids a lot of metadata atime updates (but not all of them, obviously, there's 'noatime' for that). It's like noatime, but useful for applications like mutt that need to know when a file has been read since it was last modified. Currently only OCFS2 supports it. A corresponding patch against mount(8) is available [http://userweb.kernel.org/~akpm/mount-relative-atime.txt here]. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=47ae32d6a54955a041cdc30b06d0bb16e75f68d5 (commit)], ocfs2 support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7e913c53609d5e8374f55d6f29c0bcd6650a2362 (commit)]

UDP-Lite support

Support for UDP-Lite ([http://www.ietf.org/rfc/rfc3828.txt RFC 3828]) for IPv4 and a extension for UDP-Lite over IPv6 is added in 2.6.20. UDP-Lite is a Standards-Track IETF transport protocol whose characteristic is a variable-length checksum. This has advantages for transport of multimedia (video, VoIP) over wireless networks, as partly damaged packets can still be fed into the codec instead of being discarded due to a failed checksum test. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob_plain;f=Documentation/networking/udplite.txt;hb=HEAD Documentation and programming guide]

[http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ba4e58eca8aa9473b44fdfd312f26c4a2e7798b3 (commit)]

Generic HID layer

Various core changes

Make the readside of the radix-tree RCU lockless [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7cf9c2c76c1a17b32f2da85b50cd4fe468ed44b5 (commit)]
TTY: termios revamp, adds proper speed control [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=be90038a24c814dc98bc5a813f41855779000018 (commit 1]

[http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=edc6afc5496875a640bef0913604be7550c1795d 2] [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=606d099cdd1080bbb50ea50dc52d98252f8f10a1 3] [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=64bb6c5e1ddcd47c951740485026ef08975ee2e6 4] [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=592ee3a5e5e2a981ef2829a0380093006d045661 5)]

Generic BUG implementation [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7664c5a1da4711bb6383117f51b94c8dc8f3f1cd (commit 1], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=91768d6c2bad0d2766a166f13f2f57e197de3458 2], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=73c9ceab40b1269d6195e556773167c078ac8311 3], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c31a0bf3e1bc581676618db7492f18798fd0a73f 4], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a8605aef813f8eb3ef4b80d32cba6a671ef8deb0 5], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e182c965b6ce0dffed0967a1be2173825a2ede2f 6)]
New swap token algorithm. The old algorithm had a crude timeout parameter that was used to handover the token from one task to another. The new algorithm transfers the token to the tasks that are in need of the token. The urgency for the token is based on the number of times a task is required to swap-in pages. Accordingly, the priority of a task is incremented if it has been badly affected due to swap-outs. To ensure that the token doesnt bounce around rapidly, the token holders are given a priority boost. The priority of tasks is also decremented, if their rate of swap-in's keeps reducing [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7602bdf2fd14a40dd9b104e516fdc05e1bd17952 (commit)]
Optimize o_direct on block devices [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e61c90188b9956edae1105eef361d8981a352fcd (commit)]
Add numa node information to struct device [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=873481367edb18a7d0d7e5a285e6728c16bb44a9 (commit)]
Memory page_alloc zonelist caching speedup: Optimize the critical zonelist scanning for free pages in the kernel memory allocator by caching the zones that were found to be full recently (in the last second), and skipping them. Benchmarks on a 56-CPU/96GB-RAM systems can be found in the commit link [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9276b1bc96a132f4068fdee00983c532f43d3a26 (commit)]
fdtable: Implement new pagesize-based fdtable allocator [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=5466b456ed6748e0bfe02831e570004d4c04c1d7 (commit)]
Driver core: add API for internal notification of bus events [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=116af378201ef793424cd10508ccf18b06d8a021 (commit)]; show the initialization state(live, coming, going) of the module (cat /sys/module/usbcore/initstate) [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1f71740ab9714bf5ae9ee04c724ff0d5c67ca3dc (commit)]; show drivers in /sys/module/ [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e17e0f51aeea4e59c7e450a1c0f26605b91c1260 (commit)]
Add option to serialize load balancing [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=08c183f31bdbb709f177f6d3110d5f288ea33933 (commit)]

Large sched domains can be very expensive to scan. Add an option SD_SERIALIZE to the sched domain flags. If that flag is set then we make sure that no other such domain is being balanced.

Support larger block pc requests. Modify blk_rq_map/unmap_user() so that it supports requests larger than bio by chaining them together [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0e75f9063f5c55fb0b0b546a7c356f8ec186825e (commit)]
Add 'noaliencache' boot option to disable numa alien caches. When using numa=fake on non-NUMA hardware there is no benefit to having the alien caches, and they consume much memory [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3395ee0588795b0b3bd889c260e55959cf2b61f5 (commit)]
Shared page table for hugetlb pages [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa (commit)], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=cace673d376d97b0c66ffa0a49b8d588a696d5d2 (commit)]
Upgrade the minimum required compiler to gcc 3.2 [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=53569ab7851fd564427f7529b17162cba9a28407 (commit)]
Sysrq: Add new sysrq feature: Sysrq + X: show blocked (TASK_UNINTERRUPTIBLE) tasks.;useful for debugging IO stalls [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e59e2ae2c29700117a54e85c106017c24837119f (commit)]; add sysrq_always_enabled boot option [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=5d6f647fc6bb57377c9f417c4752e43189f56bb1 (commit)]
Create CONFIG_SYSFS_DEPRECATED [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=88a22c985e3545c55c9779971007f0f29f912519 (commit 1], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=805fab474ed75f9603dbde6fa74a2976868b4bd2 2], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a87cb2ac4a78c590583b52a3ed196adc6c25b6c9 3], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b9cafc7d5b8af0c71896f60dfcff40c71bd38a9a 4], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=99ef3ef8d5f2f5b5312627127ad63df27c0d0d05 5)]
Add child reaper to pid_namespace [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=84d737866e2babdeab0c6b18ea155c6a649663b8 (commit)]
Allow user processes to raise their oom_adj value [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=8fb4fc68ca391862b061b3d358a288ccf6abed39 (commit)]
Use softirq for load balancing [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c9819f4593e8d052b41a89f47140f5c5e7e30582 (commit)]
LOG2: Implement a general integer log2 facility in the kernel [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f0d1b0b30d250a07627ad8b9fbbb5c7cc08422e8 (commit)]
bit reverse library [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a5cfc1ec58a07074dacb6aa8c79eff864c966d12 (commit)]
Implement prof=sleep profiling. TASK_UNINTERRUPTIBLE sleeps will be taken as a profile hit, and every millisecond spent sleeping causes a profile-hit for the call site that initiated the sleep [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ece8a684c75df215320b4155944979e3f78c5c93 (commit)]
kprobes: enable booster on the preemptible kernel [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b4c6c34a530b4d1c626f4ac0a884e0a9b849378c (commit)]
Switch pci_{enable,disable}_device() to be nestable, so that eg, three calls to enable_device() require three calls to disable_device(). The reason for this is to simplify PCI drivers for multi-interface/capability devices. These are devices that cram more than one interface in a single function. A relevant example of that is the Wireless [USB] Host Controller Interface [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bae94d02371c402408a4edfb95e71e88dbd3e973 (commit)], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=95ddc5f25590e31843a09357365d5cbc6ec978db (commit)]

Architecture-specific changes

i386
- Support for Processor Data Area (PDA). From now, the kernel will use the %gs register as the PDA base-segment (the old value of %gs is saved away). This will make possible to do some optimizations in the future (in this release, 2.6.20 will use the PDA to get the 'current' task in a single instruction, as an example) [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9ca36101a8d74704d78f10910f89d62de96f9dc8 (commit 1], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f95d47caae5302a63d92be9a0292abc90e2a14e1 2], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=49d26b6eaa8e970c8cf6e299e6ccba2474191bf5 3], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b2938f880890ebfcccad356275e0000193153623 4], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ec7fcaabbfb3c5bd5189f857b6ac7bb9745ef291 5], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=70463daca852db396ce17f179d2404b257ba0f66 6], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=62111195800d80c66cdc69063ea3145878c99fbf 7], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=66e10a44d724f1464b5e8b5a3eae1e2cbbc2cca6 8)]
- 300Hz support. It is useful to have 300Hz support when doing multimedia work: 250 is fine for us in Europe but the US frame rate is 30fps (29.99 blah for pedants). 300 gives us a tick divisible by both 25 and 30, and for interlace work 50 and 60. It's also giving similar performance to 250Hz [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=40fcfc87222e2e8af6379ec366f0cb2a411570cd (commit)]
- Add sysctl for kstack_depth_to_print [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0741f4d207a644482d7a040f05cd264c98cf7ee8 (commit)]

Add sysctl for kstack_depth_to_print. This lets users change the amount of raw stack data printed in dump_stack() without having to reboot.

Add support for compilation optimizations for Core2 [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c55d92d141b9c40c67db249de91f5c224eb49859 (commit)], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=713819989aa4dd141a37074dbc369e7c620bc619 (commit)]
x86-64: Don't keep interrupts disabled while spinning in spinlocks, like i386 [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=87e1652c7863b9ae406ff37f33c7ec2bb494d7b1 (commit)]
x86-64: Speed and clean up cache flushing in change_page_attr [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ea7322decb974a4a3e804f96a0201e893ff88ce3 (commit)]

PPC
- Enable DEEPNAP power savings mode on 970MP [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=5b43d20a4d12d94f258bbbca5fa4df8ff8a17848 (commit)] Without this patch, on an idle system I get: cpu-power-0:21.638 cpu-power-1:27.102 cpu-power-2:29.343 cpu-power-3:25.784 Total: 103.8W. With this patch: cpu-power-0:11.730 cpu-power-1:17.185 cpu-power-2:18.547 cpu-power-3:17.528 Total: 65.0W. Lower HZ to 100, it can get it as low as 60.2W. Another (older) Quad G5 went from 54W to 39W at HZ=250. Coming back out of Deep Nap takes 40-70 cycles longer than coming back from just Nap (which already takes quite a while).
- Add Efika platform support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c37858d333a50815c74349396e31a535f4128e0b (commit)]
- Add MPC5200 Interrupt Controller support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0f6c95dcabdaa8fdc95b125582bd12625adfbde6 (commit)]
- Cell
  - Add support for adding/removing spu sysfs attributes [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0344c6c5387ba335bba5a66fd44714b94c98573f (commit)], remove /spu_tag_mask file [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1182e1d351d2a910bc0fb53c00277c62235333de (commit)], cell iommu support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=165785e5c0be3ad43e8b8eadfbd25e92c2cd002a (commit)], add oprofile support for cell [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=18f2190d796198fbb5d4bc4c87511acf3ced7d47 (commit)], add isolated-mode SPE recycling support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=099814bb1f9bd9081d7c85867f8eb8c049abc1b9 (commit)], native cell support for MPIC in southbridge [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=21fb5a1d9f554970c680b801ba32184bc7c34aa0 (commit)], add a sd command (spu dump) to xmon to dump spu local store [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=24a24c85d3c35790a355138d7cd34c074cb1b3ac (commit)], add cpufreq driver for Cell BE processor [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=36ca4ba4b9728f3c420a589a3322c2fbd7ec88b7 (commit)], prepare for spu disassembly in xmon [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=4c4c8723684b1b2cd0dfdf5e0685f35642bde253 (commit)], add support for nonschedulable contexts [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=5737edd1ddbde5ab7f63bb3cb36015edbdb7c295 (commit)], implement /mbox_info, /ibox_info, and /wbox_info. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=69a2f00ce5d3a19a70b36f08eaf9049677277710 (commit)], add support for dumping spu info from xmon [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a898497088f46252e6750405504064e2dce53117 (commit)], import spu disassembly code into xmon [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ae06e374c15c5d62e08c19c15f2c247a86e240d4 (commit)], add spu disassembly to xmon [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=af89fb8041562508895c8f3ba04790d7c2f4338c (commit)], add temperature to SPU and CPU sysfs entries [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b3d7dc1967d1303d4897ff9537d29f6e077de147 (commit)], add /lslr, /dma_info and /proxydma files [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b9e3bd774bb1a90fee9b90f461a51e4ba295fe6d (commit)], add SPU elf notes to coredump. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bf1ab978be2318c5a564de9aa0f1a217b44170d4 (commit)], add shadow registers for pmd_reg [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bffd4927ba4377aa38be5450e20e0fecd2523fe3 (commit)], add low-level performance monitoring code [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d8bf96e0793f9576da545bac333b2de304958d68 (commit)], add support for registering sysfs attributes to spus [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e570beb6bb1a623849901efbf939063ec4775c9e (commit)], add support for stopping spus from xmon [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ff8a8f25976aa58bbae7883405b00dcbaf4cc823 (commit)],
- Add non-OF serial console support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0c176fa80fdfa9b4e0753e37223b056994c818d2 (commit)], add Kurobox(HG)/Linkstation-I NAS systems by Buffalo Technology support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=04d76b937bdf60a8c9ac34e222e3ca977ab9ddc8 (commit)], support ibm,dynamic-reconfiguration-memory nodes [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0204568a088fecd5478153504f9476ee2c46d5bf (commit)], add xserve cpu-meter driver [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3e00a5aec3d6af687e37f4e7482f5c7ecdcabd0b (commit)], add lite5200 board support to arch/powerpc [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6b64253139a20b7db1f701a9117bc5174eb878bc (commit)], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c6d4d657c2f11fe3b33dd8303f57a8b8d55323d6 (commit)], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6065170cf75c64267f6edec5fd359ce8444bd13d (commit)], allow CONFIG_BOOTX_TEXT on iSeries [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=80814be40e1f0e7e6fc00fdfe0af16268670e0b4 (commit)], import updated version of ppc disassembly code for xmon [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=897f112bb42ed9e220ce441e7e52aba3a144a7d6 (commit)], allow xmon to build on legacy iSeries [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bbb681779012fae778c0a53081bbb19cf43bca4e (commit)], make 970MP detectable by oprofile [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=fecb352f6bb86564b24ecbf7e5bfec09346b9327 (commit)], lazy interrupt disabling for 64-bit machines [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d04c56f73c30a5e593202ecfcf25ed43d42363a2 (commit)], support for DCR based MPIC [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=fbf0274e43b7e17ee740fee2d693932be093d56d (commit)]
ARM
- Add iop13xx support. The iop348 processor integrates an Xscale (XSC3 512KB L2 Cache) core with a Serial Attached SCSI (SAS) controller, multi-ported DDR2 memory controller, 3 Application Direct Memory Access (DMA) controllers, a 133Mhz PCI-X interface, a x8 PCI-Express interface, and other peripherals to form a system-on-a-chip RAID subsystem engine. The iop342 processor replaces the SAS controller with a second Xscale core for dual core embedded applications. The developer's manual is available here: ftp://download.intel.com/design/iio/docs/31503701.pdf [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=285f5fa7e9a35e75d9022f9b036ed709721c5cdf (commit)]
- AT91: Initial support for AT91SAM9261 and AT91SAM9260 [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=62c1660d908c44663c63ad6c679f6afa1d33c5f6 (commit)], SAM9 platform devices [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=86ad76bb2db7029343f681359c4b328fd8c36ae8 (commit)], Update drivers for new headers [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=55d8baee4a0b4709061104f7a56f53a310de76ac (commit)], split up system header file [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6171de8f57e80873436345a9c7ba8bae800e577b (commit)], rename user peripheral header files [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a5c474580b8b7cc8b7b2cca9a2bd27ff5c065e70 (commit)], support for Atmel AT91SAM9260-EK board [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b85a8914033d81077e8276df1956bf3307bb31bd (commit)], hardware headers for SAM9 perhipherals [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=eaa595cb881bba043e79638c37cb357f296a7714 (commit)], support for Atmel AT91SAM9261-EK board [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=022cbd7376fcdf030fe821636f1c910c45a9356a (commit)], final SAM9 intergration patches. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=05043d08045271eb5655308371dd285a852ef855 (commit)], SAM9 timer driver [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1a0ed732afdbd4b960a4b93f78fddc71b8076e61 (commit)]
- clocksource driver for netx [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1a815aed1e03c73fcd0390109c7da9c69dc97490 (commit)] and pxa2xx [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c80204e5d67d1452ac0b761d980f1651dc2c66dc (commit)]
- H1940: suspend to RAM support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9073341c2ba5d5e77b3d05d84cf9e3a16e8a7902 (commit)]
- MX/MX1 CPU Frequency scaling support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3c8cd0cce9ab8a25dbcf519cb0de00d2716f8379 (commit)]
- ep93xx: add cirrus logic edb9302a board support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=47d7e524b7d51aa77b381fbc9b9c5d3f309e434e (commit)], add ads sphere support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=5283304bdcb4af47c46280ac21100d037d31fcf0 (commit)]
- RX3715: suspend to RAM support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bbf6f2809dbadc2bacfd73a052d8b0893dbf1762 (commit)]
- Add sys_*at syscalls support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bca0b8e75f6b7cf52cf52c967286b72d84f9b37e (commit)]
SH
- Dyntick infrastructure. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bd156147eb63ae525e0ac67868e41a808f03c532 (commit)]
- Add initial support for the SH7206 (SH-2A) and SH7619 (SH-2) MMU-less CPUs [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9d4436a6fbc8c5eccdfcb8f5884e0a7b4a57f6d2 (commit)]
- Add support for Solution Engine 7206 and 7619 boards. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f36af3fd377081d3ac2ff6b63a60f8db8b3bf531 (commit)]
- Preliminary support for SH-X2 MMU. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=21440cf04a64cd1b1209c12a6e1a3afba2a28709 (commit)]
- SH-MobileR SH7722 CPU support. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=41504c39726a7099e5a42508dd57fe561c8b4129 (commit)]
- Generic push-switch framework. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9f5e8eee5cfe1328660c71812d87c2a67bda389f (commit)]
- Stacktrace/lockdep/irqflags tracing support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=afbfb52e47273a440df33274452c603e8c332de2 (commit)]
- Add SH-2A platform headers. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b229632abd451ab2c797010b9788e48c9314db4f (commit)]
S390: Add runtime switch for qdio performance statistics [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=34249d0f9243fce773c2fa352934ba108320e234 (commit)], add virtual memmap for s390. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f4eb07c17df2e6cf9bd58bfcd9cc9e05e9489d07 (commit)], add dynamic subchannel mapping [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=2ec2298412e1ab4674b3780005058d4f0b8bd858 (commit 1], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=529192f3b90682e37c5fcab461d968d062f1e0e4 2], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7674da77cb2d27ae6559c55151da171ceb02beb4 3], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d7b5a4c94f49131811112526f7d404a50f0b5ca7 4], [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7f090145a14afc35844dce80174c9c24f9e66ec5 5)]
MIPS: Add support for kexec [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=583bb86fbb9e85287f020fe4eb5352a0ec3c66a3 (commit)], add STB810 support (Philips PNX8550-based) [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f0647a52974daccbe20990fb6341f07792445fe0 (commit)], oprofile kernel support for the R10000. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=714cfe7865e5182a3b25be6a95c0b17aa8e64aa9 (commit)]
SPARC: Add irqtrace/stacktrace/lockdep support. [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=10e267234cc0133bc9ed26bc34eb09de90c248c0 (commit)]
IA64: Kexec and kdump support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a79561134f38de12dce14ed72138f38e55ef53fc (commit)]
M32R: bootloader support for OPSPUT platform [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d93f7de8c5dfefb030a5e65d0857176879bf78e9 (commit)]
m68knommu: add SHM support [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1bddcc50c27c8ca39a62a1d37e3928707be8f850 (commit)]

Various subsystems

Drivers

Graphics

Sound

The scheduled removal of the OSS drivers depending on OSS_OBSOLETE_DRIVER: miroSOUND PCM20 radio, Creative SBLive! (EMU10K1), Crystal SoundFusion (CS4280/461x), AD1816(A) based cards, AD1889 based cards (AD1819 codec), ACI mixer (miroSOUND PCM1-pro/PCM12/PCM20), NM256AV/NM256ZX audio support, Yamaha OPL3-SA2 and SA3 based PnP cards [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c67220480e0dc6442851691c81c2ff7aa48f9d8f (commit)]
hda-codec - Add model for HP q965 [http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=efeccac5b79d3569112c886396935ce574f6af9e (commit)]