Linux 2.6.0 Kernel Released

thenextpresident writes "It's here! Just updated on kernel.org, the Linux 2.6.0 kernel has finally arrived! We've been waiting a long time for this, and it had been rumored it was going to be released tonight. Well, it's here indeed. Happy downloading." There's also a changelog online for this long-awaited update.

Comments

Save the mirrors! Use bittorrent!

[algeliten]

Got a torrent of it for ya'll:

Linux 2.6.0 final (tar.bz2)

Re:So what is new?

[Kourino]

Read Dave Jones' "post-Halloween documents". You'll have to read them from backups, since the host davej's website is usually on recently suffered some sort of catastrophic hardware failure.

Re:So what is new?

[petabyte]

Thats a bit of a long list. New scheduler, pre-emption for the kernel, some new drivers, ALSA is the default for sound in this version. You can burn cd's without ide-scsi. devfs is now deprecated in favor of udev (which is roughtly the same thing but userspace as opposed to devfs's kernelspace). sysfs is also new in 2.6 which adds some information mounted in /sys. I hear firewire support is much improved as well and many other things I'm probably forgetting.

To the end user (me) 2.6 is much faster than 2.4 both in boot time and while operation. Kudos to all of the developers :). Now you'll have to excuse me while I reboot.

Re:How does this benefit me?

[Billly Gates]

Its really the first industrial strength version to compete agaisnt the big Unixies like Solaris and Aix. Full 64-bit support for the newer Opterons, full G5 support for the new powermacs, access to files that are up to 2 terribytes in size on 64 bit platforms with much better async i/o, support for up to 32-64 processors with advanced Numa!! The virtual memory has been improved and this version is a database server powerhouse.

For a desktop, real time support. Low latencies, improved USB and Firewire device support, better i/o and less race conditions during heavy disk use. It just feels alot faster and performs much better.

Its a big upgrade with mostly server oriented features but it should be a nicer desktop OS and it can perform better under loads for your scientific computing cluster.

But remember do not install it if you do not have a real up to date distro! Module tools have been upgraded and are incompatible with older versions. You can wreck your system if your not carefull.

Changes from 2.4 to 2.6

[Kourino]

For a summary of changes from 2.4 to 2.6, read Dave Jones' "post-Halloween" document. (The Changelog only lists changes from -test11 to 2.6.0 and so is not very useful. However, a full Changelog from 2.5.0 to 2.6.0 would be massive information overload, as well as just not terribly useful for a broad picture of what's different.)

Re:So what is new?

[ninkendo84]

http://www.kniggit.net/wwol26.html

This is a great place to start. It's very comprehensive, and a worthy read.

But if you really want a ultra-summed-up explination, 2.6 has 63.8% more kickassedness than 2.4 does. That and ALSA support built in.

Re:How does this benefit me?

[xwred1]

This is a good summary from a high level.

nvidia drivers/patches

[state*less]

nvidia users might want to download the proper patches before trying out 2.6. the patches can be foundhere

the start of something?

Re:How does this benefit me?

[Kourino]

Read Dave Jones' post halloween document. It summarizes the differences between 2.4 and 2.6.

Linus' mail about 2.6.0

[Shanes]

Here

Re:How does this benefit me?

[mattdm]

Try the first paragraph of this story for a bunch of technical links. Or this one from Linuxworld for a more introductory overview.

But probably what you really want is Joseph Pranevich's Wonderful World of Linux 2.6.

2.4 to 2.6

[GustavoT]

For those of us upgrading from 2.4 to 2.6 and don't know where to begin, you may want to check out an upgrade guide.

It's small but very helpful for someone that doesn't completely know what they're doing.

Whee for university bandwidth

[billatq]

I'm sitting on top of a decently fast link and I'm leaving tomorrow, so I suppose this mirror couldn't hurt: linux-2.6.0.tar.bz2.

Re:How does this benefit me?

[nathanh]

I run linux as my desktop at home, and I also run it at work in a scientific computing cluster.

I'd like to know what benefits I could expect from the new kernel in each area in which I use linux.

Desktop users will benefit from significantly faster and less "jerky" performance.

New sound (ALSA) and video (V4L2) subsystems with improved features and performance.

Much better USB and Firewire support.

Increased hardware support, especially in the areas of bluetooth and wireless.

Under-the-hood changes (threads, reentrancy, preemptiveness, scheduler, block I/O) means your applications should all run a bit faster.

Your scientific cluster applications probably won't see any benefit unless you're hitting hard limits on memory capacity or network performance. In my experience, scientific applications are all CPU bound anyway and could be running on DOS for all it matters.

More accurate information at Wonderful World of Linux 2.6.

I'll answer the one I know about

[Kjella]

"The new kernel also monitors for new events more frequently--1,000 times per second instead of 100--a fact that slows down the system about 1 percent..."

I assume it's to try and respond to events faster but increasing it tenfold, isn't that overkill? I mean, it slows the system down by 1% which isn't horrible and if a real-time app has a problem with it, you can always modify the kernel yourself but couldn't they have upped the polling to 250 which is a decent increase but not a 10x one.

Polling 100 times a second has been the standard figure in the Linux kernel for a long long time. Meanwhile, the top CPU speed has increased by much more than one order of magnitude (say 300MHz -> 3GHz). Most desktop distributions have already been shipping with this set to 1000 already, since it makes the machine overall more responsive, something that's particularly important for a GUI.

I'm guessing that on a top-of-the line server pushing bits to this disk here, that NIC there at very high speeds, it'd be just as good as the old setting, keeping buffers flowing. That 1% quote is completely without context, and might be true on a really low-end machine where 1000 context switches takes up a lot of CPU time, but overall I don't think that's accurate.

Edit: I found this quote on a google search:
"I don't know what the costs of a higher HZ value might be, except for the obvious one: more cpu cycles will be spent servicing the timer interrupt. On my PPro, servicing the timer interrupt takes around 1500 cycles, so with HZ = 100 this accounts for fraction of a percent of the processor's time. With HZ = 1024, this still wouldn't be much more than one percent (I expect the figures to be similar for a K6)." So that figure might be accurate for a 150MHz Pentium Pro...

If you're running an embedded system or something else on limited hardware, you'd probably want to tweak that now, but then again you probably should have tweaked a lot of kernel settings in the past as well. So nothing new here, just staying with the times. Hell, on a GUI machine I'd consider experimenting with setting it even higher.

Kjella

Up and running with 2.6.0!

[f-matic]

Just finished getting 2.6.0 compiled and installed on a Debian sid box with only a few hassles to get everything running smoothly... Here's some notes from the install - old news for those running 2.6 test kernels but figured someone may be interested:

-make xconfig looks really professional now
-make / make modules / make modules_install has all been tidied up by the looks of it -- no more endless printout of GCC syntax. had me worried for a second that nothing was compiling but overall looks pretty slick
-alsa comes installed as default, but the configuration seems a little screwy (on debian at least) -- /etc/modules.conf contains only OSS aliases, no alsa config files at all. so no sound at the moment...
-usb mouse doesn't seem to work here when compiled in the kernel, but works fine as a module -- same problem i've had with 2.4.18-23
-the nvidia 2.6.0 patch available at minion.de works great, so i have a functional X11 server with nvidia modules

The only thing I can find to fault is that somehow the X11 server on the backup 2.4.23 kernel crashes on bootup due to some problem parsing the XF86Config-4 file. I'm not sure if this is a side-effect of the 2.6.0 install or something else (maybe some apt-get update X11 changes i missed?), and i've had the occasional problem before with older kernels becoming only partly functional after newer kernels are installed.

All around though, nice job! Compiling the kernel is getting easier and nicer to look at. And it seems the problems with mouse lagging during 100% CPU usage are gone, at least as far as I've tried it this evening.

Thanks to Linus and all that contributed..

Re:NOT OT

[Anonymous Coward]

Windows uses SCSI-emulation just like Linux 2.2 and 2.4. Using ATAPI directly is one place where Linux is way AHEAD of windows.

If you are complaining that CD-burning was not setup for you automatically (which has nothing to do with kernel 2.6), throw out your geek-friendly Gentoo, and use a user-friendly distro instead, which will setup things just like windows.

Be aware of known security issues

[woods]

You might want to keep an eye on your 2.6.0 machine if it's on a network that's readily accessible to the outside world. Apparently not all of the security fixes that occurred in the 2.4 line have made it into 2.6.0.

Dave Jones' post halloween document, which is mentioned in an earlier post as a good summary of changes, mentions the following (near the bottom):

Security concerns.
~~~~~~~~~~~~~~~~~~
Several security issues solved in 2.4 may not yet be forward ported
to 2.6. For this reason 2.6.x kernels should not be tested on
untrusted systems. Testing known 2.4 exploits and reporting results
is useful.

Notable Changes from a Sys Admin's Perspective

[Monster Zero]

I have been following the development of the 2.6 kernel for some time now, and I have been tracking the enhancements that seem most important to me for our 130 proc Beowulf cluster:

• 2.6 offers you the ability to configure the way core files are named through a /proc/sys/kernel/core_pattern file.

• Since Linux 2.5.1 it is possible to atomically move a subtree to another place. The usage is...
  mount --move olddir newdir
  
• Since 2.5.43, dmask=value sets the umask applied to directories only. The default is the umask of the current process. The fmask=value sets the umask applied to regular files only. Again, the default is the umask of the current process.
  
• Directories can now be marked as synchronous using chattr +S, so that all changes will be immediately written to disk. Note, this does not guarantee atomicity, at least not for all filesystems and for all operations. You *can* be guaranteed that system calls will not return until the changes are on disk; note though that this does have has some significant performance impacts.

  EXT3:

• The ext3 filesystem has gained indexed directory support, which offers considerable performance gains when used on filesystems with directories containing large numbers of files.
• In order to use the htree feature, you need at least version 1.32 of e2fsprogs.
• Existing filesystems can be converted using the command
  tune2fs -O dir_index /dev/hdXXX
  
• The latest e2fsprogs can be found at http://prdownloads.sourceforge.net/e2fsprogs

  http://xenotime.net/linux/doc/network-interface-na mes.txt

• The ext2 and ext3 filesystems have new file allocations policies (the "Orlov allocator") which will place subdirectories closer together on-disk. This tends to mean that operations which touch many files in a directory tree are much faster if that tree was created under a 2.6 kernel.

  NFS:

• Basic support has been added for NFSv4 (server and client)
• Additionally, kNFSD now supports transport over TCP. This experimental feature is also backported to 2.4.20

  Profiling:

• A system wide performance profiler (Oprofile) has been included in 2.6. With this option compiled in, you'll get an oprofilefs filesystem which you can mount, that the userspace utilities talk to. You can find out more at http://oprofile.sf.net/
• You need a fixed readprofile utility for 2.6. Present in util-linux as of 2.11z

  CPU frequency scaling:
  

• Certain processors have the facility to scale their voltage/clockspeed. 2.6 introduces an interface to this feature, see Documentation/cpufreq for more information. This functionality also covers features like Intel's speedstep, and the Powernow! feature present in mobile AMD Athlons. In addition to x86 variants, this framework also supports various ARM CPUs. You can find a userspace daemon that monitors battery life and adjusts accordingly at: http://sourceforge.net/projects/cpufreqd

  LVM2 - DeviceMapper:
  

• The LVM1 code was removed wholesale, and replaced with a much better designed 'device mapper'.
• This is backwards compatible with the LVM1 disk format.
• Device mapper does require new tools to manage volumes however. You can get these from ftp://ftp.sistina.com/pub/LVM2/tools/

  From http://www.kniggit.net/wwol26.html:
  

• The number of unique users and groups on a Linux system has been bumped from 65,000 to over 4 billion. (16-bit to 32-bit), making Linux more practical on large file and authentication servers. Similarly, The number of PIDs (Process IDs) before wraparound has been bumped up from 32,000 to 1 billion, improving application starting performance on very busy or very long-lived systems. Although the maximum number of open files has not been increased, Linux with the 2.6 kernel will no longer require you to set what the limit is in advance; this number will self-scale. And finally, Linux 2.6 will include improved 64-bit support on block devices that support it, even on 32-bit platforms such as i386. This allows for filesystems up to 16TB on common hardware.

Desktop users should wait for the -mm tree updates

[Anonymous Bullard]

From: Andrew Morton (xxxx@osdl.org)
Date: Thu Dec 18 2003 - 00:15:50 EST

---cut---
Desktops and laptops may have more trouble at this time because of the much wider range of hardware and because of as-yet unimplemented fixes for the hardware and BIOS bugs from which these machines tend to suffer.

During the 2.6.0 stabilization period a significant number of less serious fixes have accumulated in various auxiliary kernel trees and these shall be merged into the 2.6 stream after the 2.6.0 release. Many of these fixes appear in Andrew Morton's "-mm" tree (...)
---cut---