1. Prominent features (the cool stuff)

1.1. Wait until the release

2. Drivers and architectures

All the driver and architecture-specific changes can be found in the [http://kernelnewbies.org/Linux_2_6_38-DriversArch Linux_2_6_38-DriversArch page]

3. Core

Add /proc/consoles: To see which character device lines are currently used for the system console /dev/console, you may simply look into this file [http://git.kernel.org/linus/23308ba54dcdb54481163bfb07dd8aeca76a7a2e (commit)]
Add hole punching support to fallocate() [http://git.kernel.org/linus/79124f18b335172e1916075c633745e12dae1dac (commit)]
Script for automatic kernel testing: ktest.pl [http://git.kernel.org/linus/2545eb6198e7e1ec50daa0cfc64a4cdfecf24ec9 (commit)]

4. CPU scheduler

Improve cpu-cgroup performance for smp systems significantly by rewritting tg_shares_up [http://git.kernel.org/linus/2069dd75c7d0f49355939e5586daf5a9ab216db7 (commit)]
Remove long deprecated CLONE_STOPPED flag [http://git.kernel.org/linus/43bb40c9e3aa51a3b038c9df2c9afb4d4685614d (commit)]
Add sysctl_sched_shares_window for the shares window [http://git.kernel.org/linus/a7a4f8a752ec734b2eab904fc863d5dc873de338 (commit)]

5. Memory management

mlock(): do not hold the mmap_sem lock for extended periods of time while loading data into the page cache [http://git.kernel.org/linus/53a7706d5ed8f1a53ba062b318773160cc476dde (commit)], [http://git.kernel.org/linus/fed067da46ad3b9acedaf794a5f05d0bc153280b (commit)]

6. Block

Implement media polling for removeable in the kernel [http://git.kernel.org/linus/77ea887e433ad8389d416826936c110fa7910f80 (commit)]
Allow creation of hierarchical cgroups in the blk cgroup controller [http://git.kernel.org/linus/bdc85df7a8417b9893443ff5520804699416b6f3 (commit)]
Export a read-only sysfs attribute for partitions [http://git.kernel.org/linus/34db1d595ef6f183fbc1e42cda45a3dfa0035258 (commit)]

Device Mapper (DM)

Improve significantly write throughput when writing to the origin with a snapshot on the same device [http://git.kernel.org/linus/d9bf0b508ddfe19883b982b29a03c02ccbf53806 (commit)]
Improve sequential write throughput [http://git.kernel.org/linus/8d35d3e37eed884ba15229a146df846f399909b4 (commit)]
dm-crypt: scale to multiple cpus [http://git.kernel.org/linus/c029772125594e31eb1a5ad9e0913724ed9891f2 (commit)]
dm-crypt: add loop AES IV generator [http://git.kernel.org/linus/34745785937a2003c144c0d4802fa637470d87af (commit)]
RAID1: support discard [http://git.kernel.org/linus/5fc2ffeabb9ee0fc0e71ff16b49f34f0ed3d05b4 (commit)]
Skeleton for the DM target that will be the bridge from DM to MD (initially RAID456 and later RAID1). It provides a way to use device-mapper interfaces to the MD RAID456 drivers [http://git.kernel.org/linus/9d09e663d5502c46f2d9481c04c1087e1c2da698 (commit)]

7. File systems

XFS

Add manual SSD discard support via the FITRIM ioctl [http://git.kernel.org/linus/a46db60834883c1c8c665d7fcc7b4ab66f5966fc (commit)]
Convert inode cache lookups to use RCU locking [http://git.kernel.org/linus/1a3e8f3da09c7082d25b512a0ffe569391e4c09a (commit)]
Dynamic speculative EOF preallocation [http://git.kernel.org/linus/055388a3188f56676c21e92962fc366ac8b5cb72 (commit)]

CIFS

Add strictcache mount option. In this mode the client reads from the cache all the time if possible. As for write, the client stores a data in the cache when possible [http://git.kernel.org/linus/d39454ffe4a3c85428483b8a8a8e5e797b6363d5 (commit)]
Add cruid= mount option [http://git.kernel.org/linus/bd7633195581c7665ce9dd80c665ec93466d1b64 (commit)]

EXT2/3

Speed up file creates by microoptimizing some functions [http://git.kernel.org/linus/40a063f6691ce937a3d00c9700b6964b5ec4e022 (commit)], [http://git.kernel.org/linus/a4ae3094869f18e26ece25ad175bbe4cd740e60b (commit)]
Add batched discard support for ext3 [http://git.kernel.org/linus/b853b96b1dbdc05fc8eae141a595366d8172962b (commit)]

SQUASHFS

Add XZ compression [http://git.kernel.org/linus/7a43ae523744c01b6187013e781f44c2281c579c (commit)], [http://git.kernel.org/linus/81bb8debd0d570dc67dc1e9d8b612632cb941893 (commit)]

NILFS2

Support the fiemap ioctl, used to get extent information for a inode [http://git.kernel.org/linus/622daaff0a8975fb5c5b95f24f3234550ba32e92 (commit)]

8. Networking

Increase default initial receive window. [http://git.kernel.org/linus/356f039822b8d802138f7121c80d2a9286976dbd (commit)]
Expose the per device configuration settings via netlink [http://git.kernel.org/linus/9f0f7272ac9506f4c8c05cc597b7e376b0b9f3e4 (commit)], [http://git.kernel.org/linus/b382b191ea9e9ccefc437433d23befe91f4a8925 (commit)]
IPv4: ECN-aware IP defragmentation (as per RFC3168) [http://git.kernel.org/linus/6623e3b24a5ebb07e81648c478d286a1329ab891 (commit)]
Add 32/64 bit compatibility in the ipv4 multicast ioctl SIOCGETSGCNT [http://git.kernel.org/linus/709b46e8d90badda1898caea50483c12af178e96 (commit)]

Wireless

Throughput based LED blink trigger [http://git.kernel.org/linus/e1e5406854378dfada3f33c7192b012083a5b8e0 (commit)]
Let userspace enable and configure vendor specific path selection, in accordance with the version 7.0 of the 802.11s draft [http://git.kernel.org/linus/c80d545da3f7c0e534ccd4a780f322f80a92cff1 (commit)]
Support hardware TX fragmentation offload [http://git.kernel.org/linus/f23a478075659db8a4fd62fa6e264a8bb052cc5b (commit)]
Report signal average [http://git.kernel.org/linus/541a45a142df281c974d74eac2066138fc107b23 (commit)]
Notify for dropped Deauth/Disassoc [http://git.kernel.org/linus/cf4e594ea7e55555e81647b74a3a8e8b2826a529 (commit)]
Add mesh join/leave configuration commands [http://git.kernel.org/linus/29cbe68c516a48a9a88b3226878570c6cbd83c02 (commit)]

* dcbnl: add support for ieee8021Qaz attributes [http://git.kernel.org/linus/3e29027af43728c2a91fe3f735ab2822edaf54a8 (commit)]

9. Crypto

User-space interface for Crypto API [http://git.kernel.org/linus/03c8efc1ffeb6b82a22c1af8dd908af349563314 (commit)], [http://git.kernel.org/linus/fe869cdb89c95d060c77eea20204d6c91f233b53 (commit)], [http://git.kernel.org/linus/8ff590903d5fc7f5a0a988c38267a3d08e6393a2 (commit)]
Optimized RFC4106 AES-GCM implementation using Intel AES New Instructions and the PCLMULQDQ instruction [http://git.kernel.org/linus/0bd82f5f6355775fbaf7d3c664432ce1b862be1e (commit)], [http://git.kernel.org/linus/0d258efb6a58fe047197c3b9cff8746bb176d58a (commit)]

10. Virtualization

Asynchronous page faults, which allow a guest to continue processing interrupts even when its memory is being paged in; in the case of a Linux 2.6.38+ guest, it will receive a notification that the host is servicing a page fault, and may switch into another guest process [http://git.kernel.org/linus/344d9588a9df06182684168be4f1408b55c7da3e (commit 1], [http://git.kernel.org/linus/fd10cde9294f73eeccbc16f3fec1ae6cde7b800c 2], [http://git.kernel.org/linus/631bc4878220932fe67fc46fc7cf7cccdb1ec597 3], [http://git.kernel.org/linus/7c90705bf2a373aa238661bdb6446f27299ef489 4], [http://git.kernel.org/linus/6c047cd982f944fa63b2d96de2a06463d113f9fa 5], [http://git.kernel.org/linus/6adba527420651b6cacaf392541c09fb108711a2 6], [http://git.kernel.org/linus/fc5f06fac6fb8ce469ea173370f2cd398f1d9f9a 7)]
AMD Bulldozer virtualization extensions: instruction decode assist, clean bits, xsave/avx, flush-by-asid [http://git.kernel.org/linus/38e5e92fe8c02a8766459d505423b855caf9af1f (commit)], [http://git.kernel.org/linus/81dd35d42c9aef3c1f7ae6ce4cf6a0d382661db5 (commit)]
lguest: --username and --chroot options, to drop privileges and chroot to a directory [http://git.kernel.org/linus/8aeb36e8f6d7eaa9cafc970b700414205743b258 (commit)]

11. Security

Smack

Address a number of long standing issues with the way Smack treats UNIX domain sockets [http://git.kernel.org/linus/b4e0d5f0791bd6dd12a1c1edea0340969c7c1f90 (commit)]
Introduce a new attribute SMACK64TRANSMUTE that instructs Smack to create the file with the label of the directory under certain circumstances. A new access mode, "t" for transmute, is made available to Smack access rules, which are expanded from "rwxa" to "rwxat". If a file is created in a directory marked as transmutable and if access was granted to perform the operation by a rule that included the transmute mode, then the file gets the Smack label of the directory instead of the Smack label of the creating process [http://git.kernel.org/linus/5c6d1125f8dbd1bfef39e38fbc2837003be78a59 (commit)]
Add a new security attribute to Smack called SMACK64EXEC. It defines label that is used while task is running [http://git.kernel.org/linus/676dac4b1bee0469d6932f698aeb77e8489f5861 (commit)]
Add two new hey types: trusted, which are random number symmetric keys, generated and RSA-sealed by the TPM [http://git.kernel.org/linus/d00a1c72f7f4661212299e6cb132dfa58030bcdb (commit)] and encrypted, which are kernel generated random numbers encrypted/decrypted with a 'trusted' symmetric key [http://git.kernel.org/linus/7e70cb4978507cf31d76b90e4cfb4c28cad87f0c (commit)]

12. Tracing/perf

CategoryReleases