Linux v2.6 Begins Testing

xose quotes Linus from the kernel list: "the naming should be familiar - it's the same deal as with 2.4.0. One difference is that while 2.4.0 took about 7 months from the pre1 to the final release, I hope (and believe) that we have fewer issues facing us in the current 2.6.0. But very obviously there are going to be a few test-releases before the real thing. The point of the test versions is to make more people realize that they need testing and get some straggling developers realizing that it's too late to worry about the next big feature. I'm hoping that Linux vendors will start offering the test kernels as installation alternatives, and do things like make upgrade internal machines, so that when the real 2.6.0 does happen, we're all set." You all know what to do ;) Update: 07/14 17:49 GMT by S : OverNeith writes "Joe Pranevich has done it again! He's written another summary document on what to expect in the new and upcoming 2.6 Kernel!"

Comments

Difference?

[KillerHamster]

For us newbies here, what are the relevant differences in the new kernel? Better performance? New hardware support?

Re:Difference?

[Urchlay]

The new anticipatory scheduler seems to make a much bigger difference than the preempt patch did in 2.4.

My test box is a Duron 750 with 384M of RAM, running Apache 1.3, Tomcat 4.0 (with Sun 1.4 JVM), MySQL 4.0, X11 + Windowmaker, usually running Opera and Mozilla.

With 2.6.0-test1, I can run the load average up to 3.6 or so, and Mozilla is more responsive than it ever was on 2.4, even with a completely idle system. In fact, it's almost as responsive as the ancient Netscape 4.7 on this same system (compare Netscape 4.7 with any Mozilla 1.x release, if you don't know what I mean).

I'm doing all this junk at once:

- Recompiling the kernel in a `while true' loop
- Recompiling a 100,000 Java project in a `while true' loop
- Playing mp3s with mpg123
- Untarring a kernel tarball, then deleting it, in another loop
- Using Mozilla to hit locally-hosted Tomcat servlets, which make heavy use of the local MySQL server, which has pretty large tables (biggest 2 tables are 1.6G and 400M)
- Reading /. in Opera :)

I can't make the mp3s skip, and virtual desktop switching is instant. In 2.4, even with the preempt and lowlatency patches, either Mozilla or mpg123 will freeze up, and/or Tomcat/mysql will lag badly (of course, preempt/lowlat isn't supposed to help much with background server daemon processes anyway). 2.6.0-test1's performance under load also beats the 2.5.6x and 2.5.7x kernels I tried on this machine, though most of the 2.5's were an improvement over 2.4.

It helps that all this activity doesn't cause much swap usage (hovering right around 200Kb of swap used).

BTW, if you're already able to run recent 2.5 kernels, you should be able to just throw 2.6.0-test1 in and have it work (no need to upgrade anything you haven't already, to support 2.5).

Executive summary: I'm a happy camper... If you're able to do so, you should try out this kernel on a spare box & see how you like it.

I got it before the /.ing

[Anonymous Coward]

And ive just compiled it. I was quite surprised I managed to get it to boot without it panicing. I'm even typing from the new kernel now. But there is a word of warning though. The layout of the /dev folder has been rearranged. As a result some of my programs have broke.

For example. /dev/hda, /dev/hdb/, /dev/hdc now become /dev/discs/disc0, /dev/discs/disc1, /dev/discs/disc2. So you will need to edit /etc/fstab to reflect the changes.

Does Linux 2.6 permit decent video capture?

[Sheetrock]

I've been tweaking my cheapish bttv-style card and no matter what I do I can't seem to prevent any of the video recording solutions for Linux to capture a steady stream of frames. The easiest test is to tune the card to a news network and watch the moving text on the bottom bar -- it skips in a regular pattern under Linux, but works smoothly under Windows (i.e., it's not a slow computer issue, although there could be magic in the driver that isn't being duplicated under Linux). From what I've read, it's an issue with Linux timing, and perhaps a real-time kernel would work better, but I was wondering if they've been addressing this.

Should mention that the sound capture seems to cause the problem -- without sound, the capture is smooth under Linux, but adding either ALSA or OSS to the mix guarantees problems.

Compiled, tested, working.

[indigo78]

Downloaded, compiled and installed. Working since 4 hours on a Slackware-9.0-current, asus L8460K notebook (p3/1000, 256mb ram, i440bx, S3 savage/MX, ess allegro) and quite standard compilation options (acpi, alsa, pcmcia, usb, netfilter, no ipv6, preemptible kernel). Applied patch as seen on LKML (see here) for vfsmount.
Happy testing!

BIO

[zonix]

If I remember correctly there's a new Block IO (BIO) layer included too, which should enable IDE CD burning without the need for SCSI emulation. Should speed things up somewhat.

I'm not exactly sure if this is correct - I believe I heard it a the Linux Forum in Denmark back in march. The speaker was Jens Axboe, the current cdrom subsystem maintainer.

z

timeslice and 'hyperthreading'??

[elwinc]

Two possibly dumb questions (but this is slashdot, after all). (1) Can you change the scheduler default timeslice (10 msec seems a bit long for a multi-GHz CPU). (2) does it do the right thing for hyperthreading? (for hyperthreading, the scheduler needs to understand that one of the CPUs is sorta crippled, so jobs should flop back & forth between both CPUs).

Product release cycles

[mfh]

Technical achivements aside, the most amusing thing about the 2.6 series of kernels is seeing all the large corporate entities with vested interests deal with the release schedule.

That is to say, there isn't one. I especially liked the quote from Torvalds I recently saw in a CNet news.com that basically said, "it'll be done when it's done - deal with it".

Re:majjor new features?

[Anonymous Coward]

LINUX 2.6 KEY CHANGES

Faster, more predictable performance and new APIs are on tap
[Yay]

Desktop improvements
[Whatever that means]

Universal Serial Bus 2.0 and production Bluetooth support
[Yay]

Pre-emptible kernel with low-latency kernel patches for more user responsiveness and better multimedia performance, even under heavy loads
[Like Windows XP!]

Server improvements
[Whatever that means]

Updated I/O and memory subsystem for faster throughput and scalability
[Yeah, like blast processing]

Faster, more scalable process scheduler
[Pfft]

User-mode Linux to allow multiple system images running on the same box to aid server consolidation and application separation
[Sounds like the minutes of a business meeting]

Asynchronous I/O and completion events--a big improvement for Web servers and databases
[I'll take your word for it]

Support for disks larger than 2 terabytes and for SGI's XFS enterprise file system
[OK]

Faster, POSIX-compliant threading library
[Redundant]

took me a while to make it work...

[C0vardeAn0nim0]

and it still shows nothing on screen if i pass vga=normal during boot, and it took me several atempts before I relized that regular ps/2 keyboard can be left out or compiled as a module. well, this kind of changes were expected.

after i managed to get it working (booting, with keyboard, framebuffer console, et. all) surprise... no DRM on X.

happens that for some reason X doesn't detect working agp when a Radeon 8500LE in inserted in my kt266 based mobo. even with agpgart and radeon modules loaded.

so here's a few sugestions:

leave ps/2 kboard selected by default for x86 architectures, same for a way to display the console on text mode vga and check this radeon issue.

except those minor stuff, the new kernel is great. really fast for regular use.

How to install?

[KillerHamster]

I know Slashdot isn't a support forum, but could someone point out a good tutorial for compiling and installing a new kernel? I'd like to give 2.6 a try, but I don't know where to begin.