Linux Kernel 2.6.21 Released

diegocgteleline.es writes "Linus Torvalds has released Linux 2.6.21 after months of development. This release improves the virtualization with VMI, a paravirtualization interface that will be used by Vmware. KVM does get initial paravirtualization support along with live migration and host suspend/resume support. 2.6.21 also gets a tickless idle loop mechanism called 'Dynticks', built in top of 'clockevents', another feature that unifies the timer handling and brings true high-resolution timers. Other features are: bigger kernel parameter-line, support for the PA SEMI PWRficient CPU and for the Cell-based 'celleb' Toshiba architecture, NFS IPv6 support, IPv4 IPv6 IPSEC tunneling, UFS2 write, kprobes for PPC32, kexec and oprofile for ARM, public key encryption for ecryptfs, Fcrypt and Camilla cipher algorithms, NAT port randomization, audit lockdown mode, some new drivers and many other small improvements."

Comments

Damnit!

[FunWithKnives]

And I just upgraded to 2.6.20-15! (Kubuntu Feisty Fawn)

Re:Damnit!

[arth1]

Same here -- I just went to 2.6.20, mostly because 2.6.17 no longer was supported by my distro, and 2.6.18 and 19 are somewhat buggy compared to .17 and .20. I'll wait and see before I go to .21 -- there's really nothing in there that I /need/. Others may have different needs and wants, of course.
At this point, I'm mostly interested in bugfixes, and not features. YMMV.

(Anyhow, why did someone mod your post "Flamebait"? I can't see anything in it that's inflammatory at all?)

Re:Damnit!

[andy_t_roo]

i for one regularly run linux in vmware, and am interested to see how the paravirtualization works out.

Published?

[CastrTroy]

What's with the headline? Who publishes OS kernels? I guess it could be grammatically correct and all that, but it sounds a little weird to me.

Re:Published?

[diegocgteleline.es]

It's me who sent the headline. "Publicar" (to publish) is what people usually uses for those cases in spanish. So there you've the answer for your question :)

(I also planned to add the number of months of development (almost 3, 80 days), but I forgot it)

Re:Published?

[Bacon Bits]

Hey, I always thought "release" sounded a bit like urination, but you don't hear me complaining.

Re:Published?

[Anonymous Coward]

At least they didn't publish it to Google, or it would be gone.

Re:Published?

[tomatensaft]

Note, that it's "to release" in English. :)

Re:Published?

[fjf33]

It does make sense though. What he published was the source code. Like a book? You wouldn't call publishers releasers would you? :)

Re:Published?

[Kadin2048]

Hey, I always thought "release" sounded a bit like urination, but you don't hear me complaining.

I was thinking of something else involving the same part of the body, but whatever works for 'ya.

please help...

[fattmatt]

I'm still running 1.0 Patch 9 ... should I upgrade?

Re:please help...

[R.D.Olivaw]

I'd wait for SP1 if I were you.

Bloat?

[ArcherB]

Is it just me, or are all these options that are added with every new release going to result in a bloated kernel? It seems like every release adds new stuff, but I never see anything outdated taken away.

Yes, I know that you can recompile and remove what you don't need, but most "non-uber-geek" users are not going to be able to handle that, and most distros are going to include a kernel with the kitchen sink compiled in.

Re:Bloat?

[qbwiz]

most distros are going to include a kernel with the kitchen sink compiled in.

No, most distros are going to include a kernel with the kitchen sink compiled as modules, taking up a few megabytes on the hard drive, but never loaded.

Re:Bloat?

[Lxy]

I've noticed that each time I compile a new kernel, something has been moved to [deprecated] status that was still live in the last release. All the deprecated stuff is not compiled in by default, keeping the resulting bzImage size manageable.

Most distros compile everything as modules, which generally keeps the overall size of the kernel down. Sure, bzImage grows over time (not just because of new features, but typically new patches == more lines of code), but not significantly from release to release.

Most "non-uber-geek" users don't care what's in their kernel, and if they did, they'd learn to compile it themselves. Compiling kernels has gotten easier over the years. Chances are, if you care enough about how your kernel is compiled, you'll have the skills needed to do it yourself.

Re:Bloat?

[Qzukk]

and most distros are going to include a kernel with the kitchen sink compiled in.

Actually, they use kernels with everything compiled as modules, and a separate initrd/initramfs to deal with loading the drivers required at boot time.

Re:Bloat?

[arth1]

Even if you compile something as modules, it does take up memory and resources. Much less, but still not negligible. There's hooks for the modules, plus tests in other parts on whether a module is loaded or not, in addition to much larger symbol tables.
And, of course, there's many parts that can not be made into modules at all, but have to be part of the kernel. And that makes a HUGE difference.

Is the difference really that big? Well, the machine I'm currently on has a bzipped kernel that's around 1.5 MB in size plus a 820 kB map. The alternative boot to a commercial distro (no name, no shame) has a bzipped kernel that's around 2.1 MB, plus a 2.3 MB initrd, plus a 1.2 MB System map.

The difference might not be staggering, but it's there, and the kernel is growing with each revision. Here's how the System.map has grown for the last few revision on this laptop, with no new options added:


-rw-r--r-- 1 root root 754620 Nov 30 18:32 System.map-2.6.17-gentoo-r8
-rw-r--r-- 1 root root 768275 Dec 28 15:57 System.map-2.6.18-gentoo-r6
-rw-r--r-- 1 root root 809157 Mar 26 04:28 System.map-2.6.19-gentoo-r5
-rw-r--r-- 1 root root 839371 Apr 25 22:45 System.map-2.6.20-gentoo-r6


That's an 11% increase without adding anything. Similar for the kernel itself (although that's harder to compare directly, due to the bzip2 compression). While not alarming, it's a trend towards feeping creaturitis that I think bears watching.

Re:Bloat?

[h890231398021]

Compiling kernels has gotten easier over the years.

You're joking, right? I used to compile my own kernel.org kernel in 2.4 days. Starting with 2.6, there are so many options, many dependent on whether other options are selected or not, that I find it impossible to figure out what I need to check and what can be left out.

No, I'd say that 2.6 ushered in the age of relying on your distro to compile the latest kernel for you and provide it as an update. This is particularly true because the kernel.org 2.6 releases, IMHO, have not been nearly as stable on release as the 2.4 ones were, and so you also end up relying on your distro to apply whatever bugfixes-du-jour are needed.

Re:Bloat?

[ehrichweiss]

Are you referring to the 2.4 days as actual compile time or time it took you to work out what to include in the kernel config? I don't think it ever took more than 8 hours to configure and compile a new kernel on my end even if the machine doing the compiling was 1/10th the speed of, then, current computers.

Plus, I don't find it THAT hard to configure the new kernels but I take my distro's config file and remove anything I know I don't need rather than starting with a blank-slate config and THEN trying to figure out what to include/remove.

Re:Bloat?

[HomelessInLaJolla]

I had begun making a similar observation to myself towards the 2.4.20+ line and definitely when 2.6 came out. It correlated nicely with the media increase in Linux coverage, the size and comprehensive nature of desktop environs like KDE and Gnome, the size of Xorg/Xfree86, and the increasing popular emphasis on web applications and the tion of HTTP and file-sharing protocol network usage over nearly anything else (spam excepted). I've almost decided that the computer programming age, as an affordable hobby for the non-specialist, is nearing the end of its lifetime. In a few more years you'll have the option of working with entirely standardized/commoditized/completely controlled (corporate DRM style) equipment or, if that doesn't appeal to you, then you'll have to go off a polar deep end and spend absolute bricktons of time and money assembling a system using a soldering iron, a breadboard, and specialty chips ordered from remote clearinghouses in China or Russia.

Re:Bloat?

[glas_gow]

If you strip your kernel down by a sizeable amount, say less than 50% of the size of the one that came with your distro, you'll only notice a small amount of performance increase, suggesting that all the added modules aren't really bloating the system by all that much. There's an improvement, but on most modern machines it's a minimal. The only time I optimise a kernel these days, is when I'm trying to use an old machine for some ancilliary purpose.

Re:Bloat?

[Grishnakh]

I've almost decided that the computer programming age, as an affordable hobby for the non-specialist, is nearing the end of its lifetime. In a few more years you'll have the option of working with entirely standardized/commoditized/completely controlled (corporate DRM style) equipment or, if that doesn't appeal to you, then you'll have to go off a polar deep end and spend absolute bricktons of time and money assembling a system using a soldering iron, a breadboard, and specialty chips ordered from remote clearinghouses in China or Russia.

WTF are you talking about? Programming has become far more accessible to everyone in the last 20 years, and much of this is because of the rise of OSS. You just talked about Linux, KDE, Gnome, Xorg/Xfree86, etc., which are all OSS applications, developed and contributed to by thousands of hobbyists (as well as professionals). There's countless smaller projects developed entirely by hobbyists, focused on very specific niches, such as people who write small applications to support their other hobbies (ham radio, electronics, knitting, or whatever) and put them on sourceforge so other hobbyists will help them out. All this is a phenomenon that did not exist in a meaningful form back in, say, 1990, before OSS software became popular and the internet/WWW become commonplace.

Locked-down corporate-controlled DRM-infected computers are still a real danger, but the way things are currently going, I don't see this becoming a reality unless the US Government mandates it through legislation. We've already seen the beginnings of DRM lock-down with copy-protected CDs and DVDs which don't work worth a damn, and Windows Vista which is having all kinds of problems because of its excessive DRM. While I don't think Windows is going to go away in the next 5 years, I don't think we're all going to be forced into using DRMed Vista-running Dells in 5 years either, with Newegg.com out of business because building your own system is illegal.

Re:Bloat?

[Grishnakh]

I seriously doubt removing the extra modules has any effect at all on performance. These modules aren't even loaded unless your machine actually uses them. You save a bunch of HD space (but not much compared to the typical 100+GB size of drives these days), but that's about it.

You probably get a small performance increase due to using optimizations specific to your machine, like compiling specifically for your P4 or Core 2 or X2 processor, and maybe leaving out some things you don't need. But overall, I don't think all those extra modules affect performance at all, just disk space.

Re:Bloat?

[InsaneGeek]

Are people really seriously concerned about this?? Maybe its me but I dont boot my linux (or windows) systems daily, or even monthly. The flexibility that modules give me, more than outways shaving 3 seconds off the boot time...

Re:Bloat?

[init100]

Are you referring to the 2.4 days as actual compile time or time it took you to work out what to include in the kernel config?

He probably refers to the days of Linux 2.4.x, not the time taken to configure and build the kernel.

Re:Bloat?

[John Courtland]

I use linux as my desktop OS on my laptop. I shut it off all the time, so startup time does matter to me. I realize I'm an exception, but it does matter.

Re:Bloat?

[ehrichweiss]

Doh! Thanks for clarifying that..NOW it makes sense and seems far less idiotic. "2.4 days" seemed like he was INCREDIBLY aware of the time it took...not simply 3 days and not rounded up to two and a half days..heh.

Re:Bloat?

[HomelessInLaJolla]

Programming is more accessible the same way that vegetable gardens are accessible.

You're still going to buy the bulk of your groceries from one or two supermarkets and the landscape doesn't show any signs of changing any time soon.

But don't let me point out the obvious. Your leading remark "WTF are you talking about?" already tells me that you know everything .

Re:Bloat?

[Grishnakh]

Maybe I'm missing something, but while it's true that most institutional or corporate-purchased computers are bought from a handful of vendors (Dell, Lenovo, HP, etc.), I still don't see these computers being totally locked-down with DRM, enforced Windows use, etc. They're still following standard specifications. You can still take any of these computers and run Linux (or *BSD) on it.

There's also a growing, though quiet, use of OSS software and OSes in companies and governments. I don't see this going away, even with the introduction of (unpopular) Vista.

If you have some evidence that computers are very soon going to be unable to run alternative OSes and software, I'd like to see it. But I haven't read anything other than worries about things like "trusted boot", which doesn't seem to have turned into reality anywhere.

Re:Bloat?

[Grishnakh]

I'm sorry, but while maybe you don't personally know anyone who writes software as a hobby, there's tens of thousands (if not more) who do it all the time, resulting in an enormous quantity of OSS software that we have currently available. Most people may still be using Windows and other proprietary crapware like Norton, but Firefox sure has gained a lot of converts for something that's totally free and open-source.

If you really think things in computing-land are becoming more centralized to fewer vendors, you have blinders on.

Re:Bloat?

[Anonymous Coward]

2.6 and recent kernels in general are aimed at *modern computers*. Modern computers that have a *lot* more features and devices than ever before. There is absolutely no comparison to kernels back in the floppy days. If you're still using floppies you might as well be using an old kernel for whatever weathered machine you're talking about. And a microkernel's not going to reduce the overall amount of code, just push it around.

Not to mention that people who are using Linux for embedded work can still rip out a ton of stuff. You can completely omit module support and all sorts of things that contribute to so-called "bloat." The kernel is still and always has been very flexible about compiling in features, and all the code's there to mess with...

Small, fast, full of features; pick two. I think.

Re:Bloat?

[k1e0x]

Hea man, the 2.2 is still out there as lean and mean as ever.

I say that as I think 2.2 provides really good speed vs. supported hardware.

Re:Bloat?

[xenocide2]

Pray tell, how did you eliminate the possibility of existing components growing, in order to conclude modularity itself is the problem?

Re:Bloat?

[shish]

I don't see this becoming a reality unless the US Government mandates it through legislation

The common sense of the US Government is the only thing standing between us and DRM hell? Oh dear :(

Re:Bloat?

[brsmith4]

Yeah, fuck those god damned developers for writing all of this code and progressing computing. You know, cuz like hardware hasn't gone anywhere since the floppy days... those feature whores!

Re:Bloat?

[Grishnakh]

Yep, it is extremely worrying. However, the hope is that there's enough forces working against mandated DRM that it won't happen. The good news is that these forces are numerous and more powerful than it appears.

On one side, there's the entertainment lobby, and their lapdog (or co-conspirator, it's hard to tell which) Microsoft, working hard for locked-down computers and mandated DRM on everything, basically turning computers into a way to deliver pay-per-view content.

But on the other side, there's nonprofit groups like the EFF who constantly challenge these things in courts. But also importantly, there's the entire electronics industry. If they have half a brain, they know that mandating all this DRM crap will have a huge negative effect on their business. Some are on the fence, or flirting with pro-DRM activities, like Sony (mostly thanks to them also being an entertainment company) and Intel (their whole Viiv scheme is a big pay-per-view DRM-locked-down POS). But many others, while currently agnostic, might come out against DRM when they start realizing how it'll impact their business.

Re:Bloat?

[SirTalon42]

Use software suspend instead of shutting off the machine. It boots up much faster as well as shuts down possibly a little faster.

My laptop (SuSE 10.2... possibly going to switch to Kubuntu Fiesty some time in the future) has an uptime of 44 days, though every night I suspend it to the disk (and several times during the day as well sometimes). On boot I generally run the command "swapoff -a && swapon -a; echo done swap; sync; echo done sync" just to bring anything that was swapped out back into main memory (the sync isn't really needed), it seems if you have too little swap space to fit all the memory into it part will be swapped out of the memory and won't be automatically loaded on resume.

All in all, it is FAR faster to suspend (both suspend2disk and suspend2ram are faster, though on my system suspend2disk is the one that was the most reliable, although I should test suspend2ram since I'm using a much more current kernel now).

Re:Bloat?

[menkhaura]

I wish you hadn't posted anonymously, so I would mod you informative. Here are, however, a couple of links (secretly hoping to get modded informative myself) about creeping [by our favourite OSS writer] featuritis. Might as well post about second-system effect, but it would be modded offtopic, even though it isn't, if we assume that Linux 2.6 is a second system if compared to Linux 2.x where x = 4.

Re:Bloat?

[kestasjk]

What has the size of the bzipped kernel got to do with the size of the kernel in memory?
It's not even the fact that it's bzipped that makes it a nonsense measure of bloat, it's the fact that the kernel is a program which fills more memory with data than code.

If you're wondering why the kernel uses more memory on a 1GB RAM machine than a 64MB RAM machine, it's not because the kernel team have been writing hundreds of MB worth of compiled code since you last downloaded Linux; it's because increasing the size of kernel data structures often increases speed.

To take extreme examples (as you do); you could have a program with a statically compiled bitmap which simply displays the bitmap and closes. It might take up many megabytes on disk depending on the size of the bitmap.
If you want to use a sieve to break a public key you could write a program that could fit into a few kilobytes, but would take more memory than exists in the entire world to break a large key.

Re:Bloat?

[repvik]

Your "bzImage" is not bzipped. It's a gzip'ed "big zImage" (IIRC, the zImage limit was 1mb)

Re:Bloat?

[John Courtland]

I'll give it a shot. I just upgraded to Kubuntu 7.04 last week, and the shutdown menu says Suspend... I'm just really gunshy about it since I've tried various forms of suspend since Win95 and they've always just crashed the machine and I've had to reboot anyhow...

Re:Bloat?

[arth1]

True. That doesn't change the overall meaning of the post, though, nor that it's problematic to compare compressed kernel sizes directly.

Re:Bloat?

[repvik]

Indeed. I was just pointing out a common misconception. The size of 2.6 kernels is growing, and it has been growing fast for a while.
I'm working on various embedded devices, and trying to squeeze a 2.6-kernel into limited space. I assure you, this is not an easy task. ;-)

Re:Bloat?

[Grishnakh]

You're still making absolutely no sense. What exactly is the point you're trying to make anyway?

The enthusiast/hobbyist programmer isn't going to have a chance breaking into the ranks of KDE, Gnome, or Linux.

Hobbyist programmers don't really need to break into KDE, Gnome, or the Linux kernel, although there's still room for them there. Why reinvent the wheel if you don't have to? That's the whole point of these projects, to provide an excellent infrastructure for everyone to use for free so people can move on to other things.

The relative importance of hobby programming for any purpose other than rock-painting is fast approaching zero.

This is totally wrong. If you want to do OSS programming as a hobby, there's tons of places to get started. Fixing bugs and submitting patches for one. Non-core projects for another. Write a cool puzzle game for KDE; if it's any good at all, I'm sure it'll be accepted. Help out on some small utility that doesn't get much attention.

Yes, if you have a huge interest in schedulers or filesystems, you're probably out of luck. Then again, if you're just a hobbyist, you probably have no business writing a new scheduler anyway; this is serious Computer Science stuff and it's unlikely someone without a degree would be able to make a useful contribution. But if you're a hobbyist, why bother with something so esoteric and difficult anyway? Application programming is intentionally designed to be easier for good reason: so it's accessible to more people, and can be done faster. If you have some hobby, you can write useful applications for it in a much easier language like Python or Perl instead of having to understand C and all it entails (pointers, etc.). And there will be a small community of those sharing your hobby who will appreciate your program.

Pretty soon even your home HVAC thermostat is going to be running either Windows or Linux. New multimillion dollar software products are no longer going to be coming from enthusiasts who just happen to put it all together.

What's wrong with HVAC thermostats running an OS? If Linux allows the thermostat companies to make something better, in an economical way, isn't that a good thing?

KDE, Apache, Mozilla, and lots more are large software products, and are produced by enthusiasts (some paid, some not). All are free for end-users. What exactly is the problem here? Again, you're not making any sense at all.

Nobody is going to make a hot career out of being the best, most creative, most observant, most secure programmer anymore.

This sounds like a sky-is-falling attitude if I've ever seen one. There's lots of careers left in software, it just depends on your field and your expertise. There's lots of kernel hackers employed at various companies, and it's more than just the few famous names. Heck, I do kernel work (actually custom device drivers for hardware that isn't used by consumers), and no one's heard of me and likely never will.

Programming is going the way of the assembly line. The next generation of programmers might have a chance to work on the line, or they may have a chance to make foreman, but the heirarchy of the industry is drying like concrete and more nepotic than federal politics.

Again, more sky-is-falling-ism. If you want to do boring, low-skilled programming, there's lots of jobs writing horrifically boring Java apps for websites (usually internal corporate stuff). If you have much better skills, such as low-level embedded work, there's lots of jobs out there if you care to look. And there's always room for hobbyists as I've pointed out before.

Meh

[1010110010]

I haven't been able to get anything past 2.6.17 to boot successfully, I think they seriously hosed the ATA shit.

Re:Meh

[FudRucker]

personally i hate using an initrd.img and prefer to build ext2 & ext3 support right in the kernel making initrd unnecessary, if you compile file system support as a module you will need an initrd.img too so insetead of selecting an "M" select "*" you could try that...

P.S. i never use reiserfs so i can not say if this works with reiserfs or not...

Re:Meh

[1010110010]

I never build FS stuff as a module.

Seriously I don't know what the deal is, all the same options, 2.6.17 boots and anything past it won't. It'll usually hang on my IDE drive discovery.

Re:Meh

[HolyCrapSCOsux]

I'm at 2.6.20.... (FC6)
seems okay to me

Re:Meh

[elFarto the 2nd]

IIRC after 2.6.17 the SATA stuff changed quite a bit (it changed from the old SCSI based stuff, to libata), and requires turning the new options on.

Regards
elFarto

Re:Meh

[rTough]

I don't think the kernel developers hosed the ata shit.. more likely you're distribution hosed the ata shit...

And if they hosed it.... it's either a development dist or they f#*$ed up.

Re:Meh

[Kryai]

I recommend going to google and fixing your kernel configuration when you build it. Those drivers changed recently and you simply just haven't done your homework. A very simple thing to do is to build in all the SATA drivers, but you will want to narrow it down.

Re:Meh

[FudRucker]

change /dev/hd?? to /dev/sd?? (even with IDE)

it might work, No Guarantees though...

Re:Meh

[swillden]

Does it stop on "waiting for root file system to become available" or some such?

Re:Meh

[nexex]

My / is jfs and have it compiled 'in' the kernel and don't receive that. But I do get "scsi: waiting for bus probes to complete ..."

Re:Meh

[giorgosts]

My feisty has a 35% chance of mounting correctly the swap and ntfs partitions. On other occasions it boots ok, most of the times displays error and I have to reboot. I have the ext3 and swap partitions on PATA disk and ntfs on a SATA. Anyone else experienced that?

I also notice the new feisty to be much faster, but when under load, desktop slows down considerably. On edgy, however hard you loaded the machine, there was always the extra power for sth else if you wanted.

Feisty looks feels like a windows machine now.

Re:Meh

[swillden]

Hmm. No suggestions then.

Have you tried asking on LKML?

Re:Meh

[frogstar_robot]

I've changed my fstab to use UUIDs rather than device names. Once I had everything correctly labeled for a kernel my machine would boot up correctly but updating the kernel could break things. UUIDs stay the same even though disk device labeling is shifting sand at this point.

Re:Meh

[Ant P.]

libata supposedly has a driver for my old IDE-only chipset, but I've never got that to work. Maybe it just doesn't work for some people.

Re:Meh

[1010110010]

Thanks for being so condescending. I've been compiling Linux kernels since 1998, and I know how to research a problem when I run across one. There is clearly something screwed in these new IDE drivers.

Re:Meh

[Nimey]

This may be the same problem biting fresh installs of Feisty on some computers.

Try this: blacklist the ata_piix driver and tell your system to load the piix driver instead, then rebuild your initrd and reboot.

Re: Meh

[Dolda2000]

I don't know what happened in 2.6.17, but in 2.6.19 (I think) they added libata support for PATA drives (so that even PATA goes through the same SCSI layer that SATA does). If you old, not-libata drivers stopped working in 2.6.17, then maybe you can try 2.6.19 and see if the new, libata-based drivers work instead?

Re:Meh

[iceburg]

I had this problem as well, turned out to be grub's menu.lst looking for /dev/hdx instead of /dev/sdx. Changed that and it worked fine.

Re:Meh

[tinkertim]

personally i hate using an initrd.img and prefer to build ext2 & ext3 support right in the kernel making initrd unnecessary, if you compile file system support as a module you will need an initrd.img too so insetead of selecting an "M" select "*" you could try that...

Its not just the file system you need, its the ability to spin the drive containing said file system too :) Its legacy HW that's getting fuzzy , not file systems. Not really sure why you hate initrds so much?

The initrd does many more things than load drivers. What if you have an AoE based storage network with many disk-less stations needing to use an OCFS2 single system image? Initrd's can do neat things besides loading modules, have a look at linuxrc. You can bring network adapters to an up/link state, negotiate iscsi targets, download a boot config from a resource controller, all kinds of goodies. Complex networks need to do lots of things before pivot_root gets called, and we need complex networks.

piix hasn't been 'quite right' since 2.6.16.29 on most of the legacy servers using PATA (IDE) I still have up and working, many of us have been having a difficult time with it. But progress is progress, and this is good progress so I guess my move to all SAS will be sooner than later.

Re:Meh

[petermgreen]

personally i hate using an initrd.img and prefer to build ext2 & ext3 support right in the kernel making initrd unnecessary, if you compile file system support as a module you will need an initrd.img too so insetead of selecting an "M" select "*" you could try that...
If it was just a matter of filesystem support i doubt the distros would have gone down the initrd root in the first place, hell doesn't ext2 have to be compiled in anyway for some types of initrd to work.

the real issue is hardware support, the bootloader uses bios calls but once the linux kernel proper is loaded its not easilly possible to do that (it could be done but i don't think anyone has ever considered it worth writing a driver that does access windows 95 compatibility mode style by repeatedly switching back to real mode). The result is that the linux kernel has to access the hard drive without using anything that is not already in ram. There are basically two ways to do this, either you build in the drivers for the hard drive (impractical for pre-built distro kernels due to the sheer number of possible drivers) or you use an initrd (which is placed in ram by the bootloader before linux is loaded).

Re:Meh

[swillden]

I had this problem as well, turned out to be grub's menu.lst looking for /dev/hdx instead of /dev/sdx. Changed that and it worked fine.

I've seen that, but it gave me the error about waiting for root to come available, rather than the other message.

Re:Meh

[spikedvodka]

I never build FS stuff as a module.

Similar here... but with a minor change:
I never build my default FS stuff as modules

ext2/3 and JFS build right in, vfat, ntfs, hfs, etc... modules, becuase I don't need to use them all that often, only when I have to recover data off of a different drive do I need to use them

KVM management?

[drinkypoo]

Speaking of KVM (slightly offtopic, but not totally) are there any worthwhile management utilities for it yet? I actually ended up giving up for a while on KVM entirely because the video device is horribly slow and VDE support is not reliable, and I'm using vmware server, but I did have to give it a try. I'd love to use KVM (since I have supported hardware and it's Free software, and I'd love to minimize my use of the closed stuff) but beyond those problems (which will hopefully both be fixed relatively soon) there is simply no decent management software unless you're on redhate. Either virt-manager or libvirt is badly broken and won't work properly otherwise. UNLESS... has anyone out there gotten it working on debian/Ubuntu yet? I tried for a while, but I'm just not a good enough programmer and the programs ain't done yet.

Re:KVM management?

[drinkypoo]

Uh, Synergy is a program used for sharing a keyboard and mouse across multiple machines. I use it daily, with a Linux host, and two clients; one Windows XP, one Mac OSX. It doesn't manage settings and run state for KVM virtual machines. Thanks for playing, though.

Re:KVM management?

[deezilmsu]

whoops. Total misread. That's what staying up until GOD in the morning working on a paper for class will get you.

Re:KVM management?

[Anthony Liguori]

I actually ended up giving up for a while on KVM entirely because the video device is horribly slow and VDE support is not reliable

How do you mean the video device is "horribly slow". Also, what do you mean by VDE (as in, vde.sf.net?).

Re:KVM management?

[drinkypoo]

Seriously? For real? Just how much management can you need?

virt-manager is supposed to provide a vmware server console-like interface.

I need that much management if I'm going to leave vmware server.

Running shell scripts to run my virtual machines, and editing those scripts, and having those scripts create and destroy network interfaces etc, is an annoyance. I am capable of doing it, but I am lazy and would rather use someone else's tools. It's [ostensibly] only a matter of time before virt-manager works, or before gkvm is expanded to the point at which it is actually a useful tool, so I'm not going to go attempt to invent a shitty wheel when someone else is working on a nice one.

Redhat have a long tradition of wrapping stuff that doesn't need to be wrapped.

Having an interface for provisioning new virtual machines, or suspending them and later bringing them back, or changing their settings is not strictly necessary, but it is quite useful.

Later, when we are migrating KVMs between machines (I see it can do it now, but it's preliminary) we will definitely want management utilities.

If you don't want them, that's nice, but don't try to tell me that I don't want or need them. I don't need a chair, I could kneel on the floor all day, but that would be stupid. I consider this to be much the same situation.

Re:KVM management?

[drinkypoo]

How do you mean the video device is "horribly slow".

I mean that updates to the display (I was using the console interface, not a VNC) are, well, horribly slow. Some issues might be windows-specific, such as windows 2000 taking so long to turn the whole display desktop-colored (initializing video memory, I guess?) taking literally a minute or more.

And yes, by VDE I mean Virtual Distributed Ethernet. I tried both VDE and VDE2. With VDE2 it never worked properly. With vde, I could start kvm four times and have VDE work once. With no changes to the command line, or other programs being run. Just re-running the vdeq kvm ... command.

Re:KVM management?

[Breakfast Pants]

KVM--Keyboard video and mouse.

Re:KVM management?

[drinkypoo]

KVM--Keyboard video and mouse.

This is a conversation about Linux Kernel 2.6.21 and the context made it quite clear that I was talking about KVM, a feature added to the Linux kernel in 2.6.20 and with additional functionality in 2.6.21.

I didn't call the guy names or anything, if he had been paying attention he would have known what I was talking about, and he (?) :) posted an apology for not paying attention. Now it's your turn.

By the way, Synergy does NOT repeat NOT do the same thing as a KVM switch. It doesn't switch anything. It provides sharing across a single seamless desktop which in turn is made up of multiple desktops. It also provides copy and paste functionality of some data types across these platforms. It doesn't put all the video sources behind a single monitor, and it doesn't switch between anything. In fact, if your mouse pointer is on your desktop (I'm talking about the server here) then the other mice can be used to control the systems to which they are attached. The keyboards on the clients ALWAYS affect the host to which they are attached, as well.

Synergy is not a replacement for a KVM switch, it solves an entirely different problem (which has incidentally been solved before, although I forget the name of the program that did it and IIRC it was X11-only.)

Re:KVM management?

[Breakfast Pants]

You read a lot into my comment that wasn't there. I was just pointing out why he was confused.

Re:KVM management?

[Bronster]

In the finest traditions of unix naming:

x2x

Re:KVM management?

[Anthony Liguori]

Some issues might be windows-specific, such as windows 2000 taking so long to turn the whole display desktop-colored (initializing video memory, I guess?) taking literally a minute or more.

That's been fixed.

And yes, by VDE I mean Virtual Distributed Ethernet.

VDE is not part of the KVM project. The best way to deal with networking is to just setup bridges yourself.

Re:KVM management?

[drinkypoo]

VDE is not part of the KVM project. The best way to deal with networking is to just setup bridges yourself.

Well, that raises an interesting point, because I don't want to do that. I want a management tool to do it for me. So now I come back to looking for a management utility. I chose VDE because it simplified my life, or at least, was supposed to.

KVM either works with VDE or it doesn't. It says it does. If it doesn't, it should say it doesn't.

Tickless only for x86 now, still good news

[MarcQuadra]

I follow prerelease kernels and I've been waiting for this. I've found that running my VMWare hosts and guests with tickless, low-HZ, voluntary-preempted kernels is seriously reducing the overhead you get when you run more virtual CPUs than real ones in your box.

I can't wait for it to mature on PPC, MIPS, and x86_64! Right now it's 32-bit x86 only.

Re:Tickless only for x86 now, still good news

[JohnFluxx]

Can you explain this a bit more please for those of us who don't know what tickless means?

Re:Tickless only for x86 now, still good news

[AaronW]

It means that they were able to successfully remove the blood sucking parasites from the kernel.

Most kernels use a periodic system timer tick to do various housekeeping chores, like rescheduling tasks, sending packets, flushing files from the cache, etc. Usually this occurs at some periodic rate, i.e. every 1-10ms for Linux and every 10-15ms for Windows (according to this article.

This is a bit wasteful of CPU resources, since the kernel might not need to do anything for quite a while, or it might want a high resolution timer with higher accuracy than normal system timer. For example, when the system is idle, the CPU still must wake up and process a timer interrupt for every timer tick, and if it's set to 1ms there are 1000 interrupts per second.

A tickless kernel instead only schedules the next tick for when it is needed, so if the system is idle and nothing needs to happen for 50ms, then the next tick will be scheduled 50ms later. On the other hand, if a timer needs to go off in 750 microseconds, the kernel can schedule the next interrupt to go off then, giving much higher accuracy.

Re:Tickless only for x86 now, still good news

[JohnFluxx]

Does this mean things like sleep(5) will sleep for 5ms for real now, without needing to change the scheduler etc?

Re:Tickless only for x86 now, still good news

[AaronW]

sleep(5) currently sleeps for 5 seconds, however, calls like nanosleep should have much greater accuracy with a tickless timer.

Re:Tickless only for x86 now, still good news

[iabervon]

I believe you only need the clockevents portion of the new feature for that (except that you mean usleep and 5 microseconds; it's windows where the unitless sleep function is milliseconds). The first part was to have accurate code inside the kernel for "give an interrupts at this list of arbitrary times"; the second part was to make the scheduler use this mechanism for routine task switching. The big advantage of the second part is that, if nothing is going to be able to run in the next ten minutes (without external input), the CPU can suspend for ten minutes instead of waking up every millisecond or ten. And, if you've got a big virtual server, running a hundred idle kernels, those idle kernels take 0 CPU.

The third part, coming in a few kernel versions, is having the scheduler schedule different tasks for different durations according to policy and optimization. If one task is supposed to get 70% of the processor time and another is supposed to get 30%, the kernel can alternate between then, running the first for 7ms and the second for 3ms, instead of using a complicated pattern of 1ms slices.

Re:Tickless only for x86 now, still good news

[Trogre]

I have installed 2.6.21 on two identical machines sitting next to each other. One with CONFIG_NO_HZ and CONFIG_TICK_ONESHOT defined, the other without. Both are running AMD Athlon32-2600+ CPUs.
After 12 hours, both are still running at the exact same temperature, implying a similar current draw, so no real power savings yet, at least with this architecture.

However I find the one compiled with NO_Hz is actually running CPU-intensive tasks consistently 0.66% faster than the other one. For this I have no explanation, since one would think idle loops (the only place where tickless systems are supposed to benefit) aren't entered much when the CPU is going full pelt.

Re:Tickless only for x86 now, still good news

[AaronW]

A tickless solution will use a little less CPU. Now the amount of power used will not be much more with a regular tick, but it makes a bigger difference when running in a VM (VMWARE, Xen, etc.) since there is a lot more overhead to process all the timer interrupts in all of the OSes that are running. Perhaps more importantly, you can get much more accurate timers without having to increase the tick rate. If I need to sleep for 200us I don't need the timer to run at 5000 ticks/second.

That's nice and all...

[rob1980]

... but does it run Linux?

Re:That's nice and all...

[diegocgteleline.es]

Since it supports para/virtualization yes, of course, it runs linux!

(Damn, finally there's an answer for this!)

Re:That's nice and all...

[MrCoke]

Not tested I'm afraid.

Rumour is that the GNU is porting HURD to it though. They think it will enhance their GNU/Linux brand.

I need more coffee...

Another solution to a timeless problem!

[iamacat]

Once again, it took many months of work to optimize an idle loop.

The list of changes can be found...

[diegocgteleline.es]

Here.

who the h3!! marked that flamebait?

[1800maxim]

Must be Linus!

You joke,

[StarKruzr]

but I wonder if we're ever going to see 2.8 at this rate. The current kernel revision is MILES away in technology from 2.6.0. What will it take to move to 2.8, or (dare I say it?) 3.0? What qualifies as a major enough change?

Re:You joke,

[Anonymous Coward]

I wonder if we're ever going to see 2.8 at this rate

Linux 2.8 will compete with SunOS 6.0 as the best platform for running Duke Nukem Forever.

Re:You joke,

[hypnagogue]

A change to the ABI.

Oh, sorry, I didn't realize it was a rhetorical question.

Re:You joke,

[Vulva R. Thompson, P]

Well, the upcoming sister-raping feature could qualify as "major".

Details:
"The features are tested in the -mm tree, but be warned, it can crash your machine, eat your data (unlikely but not impossible) or rape your sister (just because it has never happened it doesn't means you're safe):"

Re:You joke,

[frogstar_robot]

Yeah but you still have to force your sister onto the Sidewinder. If I'm going to pay good money for Windows then I simply must have better automation than that!

Re:You joke,

[porl]

i don't much care...

Re:You joke,

[einhverfr]

Linux 2.8 will compete with SunOS 6.0 as the best platform for running Duke Nukem Forever.

I dunno. Hurd will probably give them both a run for their money.

Anyway, isn't Duke Nukem Forever written in Perl 6?

Re:You joke,

[fan of lem]

At this rate it would take them forever to catch up with Windows v95! No wonder more people are using Windows!

paravirtualization? Dynticks? new drivers?

[Anonymous Coward]

This seems like pretty good evidence that Linux is a kernel.

At last!

[Dr. Stavros]

Glad to hear that it's been published. Where can I download the PDF? I heard that Darl dies near the end, but I want to read it for myself.

Re:At last!

[fjf33]

You can download the text files. I am not sure they publish it in PDF. It's good reading, like those old teen novels where you make a decision and got to page so and so. You just have to be careful not to jump to one of those where it takes you to a user space chapter. Then you have to go somewhere else and download even more text files.

The comments at the margins are good read too.

Re:OMG F1r5t P054

[justinlindh]

Stop it. This isn't the GameFAQs forum, and nobody cares if they're the first post here. If you don't have anything to contribute, then don't post.

On topic:
All of this built-in virtualization stuff sounds great. How long, on average, does it take the Ubuntu repositories to receive new kernels?

Re:Does it still crash after 49.7 days??

[diegocgteleline.es]

You're confusing Linux with this Windows 95/98. However, this problem or this another problem are even more funnier

Sooner or later...

[heretic108]

Sooner or later, my /boot/grub/menu.lst will look like:

...
title Ubuntu, kernel 2.6.29-5-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.29-5-generic root=/dev/hda1 ro \
  coffee=cappucino,sugar=0,hourly \
  massageareas=head,neck,shoulders \
  catfeedingtimes=4_hours,15_grams
initrd /boot/initrd.img-2.6.29-5-generic
quiet
savedef ault
boot
...

Re:Sooner or later...

[ctr2sprt]

Yeah, the absurdly long kernel command lines in Linux really bug me. It's a symptom of the suckiness that is the PC BIOS, so I'm not really blaming the Linux people, but there are better solutions and have been for years. The FreeBSD loader, for instance, is capable of loading the kernel and any modules required to bootstrap the system, reading configuration files, and running Forth (!) scripts. Such a loader would completely eliminate the need for initrds on nearly all systems[1] without sacrificing any power. You could also emulate Openboot or EFI - or more realistically a subset of them - using the PC BIOS to prepare for the future.

[1] initrd is a really awesome feature and it shouldn't go away. But it's massive overkill the way it's typically used, which is to load modules required to mount the root filesystem.

Re:Sooner or later...

[ady1]

massageareas=head,neck,shoulders In this revision, they've changed added a additional feature. Now the line is like:

massageareas=head[0],neck[0],shoulder[0-1] Massage the wrong array member and the kernel will panic.

Re:Sooner or later...

[SeaFox]

catfeedingtimes=4_hours,15_grams

you forgot the
type=feline_supplement,id=25

Re:Sooner or later...

[bmk67]

Yeah, the absurdly long kernel command lines in Linux really bug me. Yeah, I know what you mean:

title=Gentoo (2.6.16-r13)
root (hd0,0)
kernel /vmlinuz-2.6.16-gentoo-r13 real_root=/dev/evms/rootfs

Doesn't get much shorter than that, though I will admit that I roll my own kernels and initramfs.

[1] initrd is a really awesome feature and it shouldn't go away. Seconded. If you use your distro's stock kernel you may require an initrd/initramfs unless the controller your root fs is on just happens to have a driver compiled into the kernel, and you have the correct filesystem code compiled in. You really don't want every possible controller/filesystem driver compiled in.

Compile your own, and you may find that you still need an initrd/initramfs because there's userspace initialization required to mount your root fs (e.g. your root fs is under volume management [EVMS/LVM], or it's encrypted).

Dynaticks: picture

[Tribbin]

These dynaticks capabilities will certainly blow you off your socks!

http://www.spymall.com/catalog/images/bombclock3.j pg

Mactel MBP C2D

[JumboMessiah]

As an owner of a Macbook Pro, I've been waiting for this to get released. The Dynticks integration will (hopefully) help lower power consumption and heat output. Though this will help reduce heat and power on all platforms, those running Linux on a MBP C2D know it's hard to keep the fans from spinning up from relatively little activity.

Next up is to get ATI to actually support any power saving features in fglrx on the MBP C2D and give the mAdWiFi guys more time to work out the features on the Atheros AR5008.

OSX, right now, still has a significant advantage in keeping heat and power consumption down. Even though, I imagine some will testify that even OSX is having a hard time with it...

Here's to testing out 2.6.21 tonight :)

Re:Mactel MBP C2D

[diegocgteleline.es]

The Dynticks integration will (hopefully) help lower power consumption and heat output.

Dynticks stil doesn't set the CPU to a power-savvy mode (it will in the future, but not in 2.6.21), so power consumption is more or less the same than without dynticks.

Re:Mactel MBP C2D

[X0563511]

Seems to be a lot of 'hype' about the Macbooks... What's the big deal that makes them so attractive? Nobody I know has used one, and the last Mac I extensively used was the Color Classic II (i've used eMacs and iMacs intermittantly, but rarely)

I'm not very happy with my aging HP laptop, and I'm starting to look at options.

I would like to use Linux, but I can also deal with FreeBSD. Windows/MacOS is out of the question for me (windows at home dual-boot for games and synthesizing, thats all)

Re:Mactel MBP C2D

[battjt]

I'm a Linux guy since 0.12. I really, really, really want a Linux laptop that works. I settled for a Unix laptop that works.

The MacBook was $1300 and features DVD RW, firewire, USB, bluetooth, wifi, a video camera, audio (record and play), a 3d graphics card and a 150 minute battery (for the way I use it). The coolest features are the little things that Apple did right: the magnetic power cord, the simple, sturdy case, the pulsing standby indicator, etc. I install the GNU bits that I need, but most of it is already there. The biggy was MacFuse so I can sshfs back to the office. My most used apps are Mail.app, Skype, ssh, Eclipse, Firefox and OpenOffice. A also use Parallels and an old w2k license to run clients VPN software and remote desktop.

It is a great piece of hardware, but the software really hasn't come that far in the last 10 years. If you have used a NeXT, then you have used OSX.

Joe

Re:Mactel MBP C2D

[wild_berry]

Next up is to get ATI to actually support any power saving features in fglrx

You don't have atitool -set-powerstate 1|2|3 in the fglrx driver? If you're running fglrx, try atitool -lsp to list the available powerstates.

Re:Mactel MBP C2D

[petermgreen]

Afaict (i don't have one but i'm thinking of getting one) the intel macs are good quality predictable (you know what your getting/its easy to research linux support) hardware and they can run mac OS X which many people think is one of the best desktop operating systems arround (lets be honest, the linux desktop is a mess of many different widget sets and poor integration) and has very good (some would say better than windows, it certainly used to be that way though increasingly software companies have been jumping ship) software support for certain arty niches (including probablly the one you mention).

Re:Mactel MBP C2D

[bill_mcgonigle]

I would like to use Linux, but I can also deal with FreeBSD. Windows/MacOS is out of the question for me

You know Mac OS X has a FreeBSD layer in it, right?

The MBP is a fast notebook of good quality, well-integrated hardware, and everything pretty much just works. OSX is a Unix and you can run other Unixes on it. I'm running FC6 in VMWare on OSX right now, for linux-specific work - you can boot straight into Linux if you want to but the hardware support isn't quite there yet. The units are well-priced in the market and Apple contributes to Open Source development - its own, and outside projects.

There's also no Microsoft tax.

Re:Mactel MBP C2D

[X0563511]

Yes, I knew of the freebsd layer, but If I were to purchase a macbook the first thing I would do is remove MacOS. I've used it a little and I don't really like it (KDE on the other hand, I do like.)

Thanks for the answers guys! That's the kind of thing I was looking for. Decent and reliable hardware seem to be the hallmarks.

Re:Does it still crash after 49.7 days??

[Gospodin]

Definitely not a Linux problem:

[webadmin@garden-ghost logs]$ uptime
5:05pm up 53 days, 5:54, 1 user, load average: 0.00, 0.00, 0.00

Cool, but...

[asninn]

That's cool, but is this really news that's Slashdot-worthy? Sites like LWN and KernelTrap have already reported this, and anyone who's interested in Linux development is pretty much guaranteed to follow the former at least, I think (and most likely the latter as well).

Re:Cool, but...

[styrotech]

I dunno, back in the day it seemed that Linux kernel development stories and release announcements were the mainstay of Slashdot news.

Re:Cool, but...

[npsimons]

That's cool, but is this really news that's Slashdot-worthy? Sites like LWN and KernelTrap have already reported this, and anyone who's interested in Linux development is pretty much guaranteed to follow the former at least, I think (and most likely the latter as well).

Considering that slashdot was (note the past tense) first and foremost a Linux/all things geeky site, I'd say this article is very slashdot-worthy. Not to mention that we get a fawning mac fan boy article every time Steve Jobs so much as farts. At least the Apple section can be turned off. Wish I could do the same with Microsoft and Windows articles.

Re:Cool, but...

[rawtatoor]

I dunno, back in the day it seemed that Linux kernel development stories and release announcements were the mainstay of Slashdot news.

Yeah, the good old days before Zonk showed up and started posting stories about prostitution in second life and how it affects the gold farming industry in WoW, and the social impact of super mario on the plumbing industry, etc. Kind of makes me yearn for Katz... I just made myself cry inside.

Re:Cool, but...

[rawtatoor]

I just had a vision... An inspirational story of poor Afghani children playing Duke Nukem Forever on an old Apple II (or whatever it was.) That will be the day. *sigh*

Re:Cool, but...

[pembo13]

here here !!

Re:Cool, but...

[Sancho]

I don't follow the kernel releases anywhere but on Slashdot, honestly. Though I'm typically interested in the new features, Slashdot usually has more information that I care about, rather than the detailed changelog that has extremely low-level changes. Generally, I'm interested in stability, security, and feature enhancements, and the summary+comments tends to hit all of the important ones in any given release.

Re:Cool, but...

[Kjella]

Slashdot used to post almost every point release when I started on slashdot, but then again there were often really important kernel changes. In recent years kernel releases have been more like "Works good like before, maybe a little better, a few more drivers, exotic functions X, Y, Z". Trip down memory lane perhaps? Maybe the virtualisation support was news enough to qualify? Fire up the good old flamewar on whether the 2.6 kernel is stable or not? Besides, with various posts to randoms blogs/slashvertisements, at least this is hardcore news for nerds, if not exactly rocking the boat.

Re:Cool, but...

[spikedvodka]

Man... I need sleep... I read that as:

"Works good like before, maybe a little better, a few more drivers, erotic functions X, Y, Z". Trip down memory lane perhaps?"

Blood content in my caffeine stream is getting too high

Hotplug CPU support!

[matt me]

Hotplug CPU support? That must burn.

Re:Hotplug CPU support!

[harrkev]

Hotplug CPU support? That must burn

Nope. Works great. Let me demonstrate...fsdjlksd+++

Re:Hotplug CPU support!

[damg]

The kernel needs to support hotpluggable CPUs for virtualizated machines. Being able to add or remove CPUs on the fly based on load will be pretty neat.

Re:Hotplug CPU support!

[verbatim_verbose]

Actually, this has been possible with Xen paravirtualized guests for some time now.

Re:Hotplug CPU support!

[petermgreen]

obviously hardware support will be needed for safe hotplugging but i don't see why it should be any less feasible to hotplug a CPU than to hotplug ram or expansion cards.

hotplugging is very important to those who run very high uptime systems, to meet thier stated uptimes some people basically can only afford to shut down every few years, in that time a fair bit of hardware can fail or need upgrading!

Re:OMG F1r5t P054

[Zonk (troll)]

Six months.

Feisty will likely be using a patched 2.6.20 until Gusty's released in October.

Re:Does it still crash after 49.7 days??

[Tom]

It doesn't and never did. However, the uptime clock wraps around after 497 days. Took me two hours of finding out why the box rebooted (and then why there was no indication of the reboot in the logs) one day to research that. That same box has since looped the clock a second time. So I can say for sure it stays up for more than 50 days. :-)

Re:Does it still crash after 49.7 days??

[AaronW]

As far as I know, Linux never had a 49.7 day problem, but it did have a problem at 497 days. I have a machine at home running the 2.4.20 kernel and every 497 days my uptime restarts, but it hasn't crashed. It's gone through 2 rollovers so far and has been up for over 3.72 years. It will hit its next rollover around September. I really need to build a new server... I just don't know if it will be as reliable as this one has been.

VMI

[wwpublishing]

Man, I'm so glad that this new version is coming out. I've been using VMI forever on windows and you know how much that sucks. This gets my stamp of approval!

Re:VMI

[audi100quattro]

Isn't VMI an ABI that uses blobs inside the kernel? I read somewhere that it wasn't going to be merged, unless someone came up with a API solution what was open to change as the developers saw fit.

Re:VMI

[www.famousstamps.org]

Yeah as far as I know. I hope someone does.

Re:Does it still crash after 49.7 days??

[Cro Magnon]

497 day wrap around? You should switch to Windows. I'm sure no such problem has ever been reported on that OS.

Spoiler

[poopdeville]

free() kills Dumbledore!

Re:Does it still crash after 49.7 days??

[Eternauta3k]

uptime
1:31PM up 2.4e+15 days, 6:37 30 users, load averages: 0.61, 0.10, 0.21
Beat that!

eCryptfs public key

[omnirealm]

The public key support for eCryptfs can handle more than just public keys. It includes a communication mechanism with a user daemon that can be queried from the kernel on file open events. There is a pluggable key module interface accessible through that daemon. OpenSSL is currently implemented, but there is nothing stopping anyone from writing a module to use GnuPG or any other key management/encryption backend, all in userspace. The module just needs to accept a key signature, and it can perform encryption and decryption based on whatever that signature refers to.

In other news, eCryptfs has recently been given the go-ahead for inclusion into Fedora:

https://bugzilla.redhat.com/bugzilla/show_bug.cgi? id=218556

In the meantime, you can grab all the userspace stuff from the eCryptfs SourceForge site:

http://ecryptfs.sourceforge.net/

Re:Does it still crash after 49.7 days??

[Gospodin]

Hey, it's not my fault that some admin kicked out the power cable 53 days ago!

Re:PWRficient support?

[TeknoHog]

Support schmupport. There are lots of things in computing that Just Work (TM) without being 'supported' officially by the manufacturer. Conversely, 'support' doesn't guarantee very much, it's just a meaningless buzzword. Then again, I41 welcome our new PWRficient overlords, especially when you can get laptops with them.

Re:Does it still crash after 49.7 days??

[Tack]

It doesn't and never did. However, the uptime clock wraps around after 497 days.

I guess that one got fixed at some point:

[root@blade1 ~]$ uptime
18:00:25 up 622 days, 23:00, 1 user, load average: 0.17, 0.22, 0.29
[root@blade1 ~]$ uname -a
Linux blade1.[redacted] 2.6.9-11.ELsmp #1 SMP Wed Jun 8 17:54:20 CDT 2005 i686 i686 i386 GNU/Linux

Quite possibly.

[jd]

Just tried the latest kernel and it hangs on trying to fire up the second ATA instance. Not even a kernel oops, nothing. That's true whether I use the vanilla kernel or Red Hat's RPM. Something is screwed up, and from the sounds of it, there's more than one of us experiencing a failure at the same point, so that would be the obvious suspect.

Re:Quite possibly.

[Daniel Phillips]

Just tried the latest kernel and it hangs on trying to fire up the second ATA instance. Not even a kernel oops, nothing. That's true whether I use the vanilla kernel or Red Hat's RPM. Something is screwed up, and from the sounds of it, there's more than one of us experiencing a failure at the same point, so that would be the obvious suspect.

This problem needs to go to lkml, and cc Andrew.

Change to the ABI

[StarKruzr]

Was that the case for 2.0 -> 2.2? 2.2 -> 2.4? etc.?

Re:Change to the ABI

[Chirs]

The development model for 2.6 is very different from previous releases. See the "version numbering" section at http://en.wikipedia.org/wiki/Linux_kernel for some details.

In general no, the ABI was not broken between previous releases (although the API has been broken numerous times).

Re:Change to the ABI

[canadiangoose]

As far as I know, that was the case for the transition from 1.2 to 2.0, as the executable file format moved from a.out to the much more advanced ELF (Extendable Linkable Format?). I believe the shift to the ELF format allowed for much more robust process control and more useful libraries.

I didn't start using Linux until 2.2.something, so this was all before my time, and I'm not a programmer, so I'm probably missing something.

Re:Change to the ABI

[petermgreen]

In general no, the ABI was not broken between previous releases (although the API has been broken numerous times).
i'm pretty sure the policy has always been that they don't care about a consistant abi even accross minor releases, i'm sure linus even came out and said so.

if the bits of the abi your modules care about didn't change that was simply a side effect of them not tweaking anything too much in that area.

if an api is broken then the corresponding abi is almost certainly broken too.

Re:Change to the ABI

[Andy Dodd]

The Linux userspace ABI has been pretty consistent for years.

Binary applications written a decade ago still run (as long as compatible libc libraries are installed or they are statically linked).

Binary modules are a different story - Internal APIs (and sometimes ABIs) do often change, but that's not what matters (unless you are one of the few vendors insisting on binary-only drivers, and most of those have worked around that problem with open-source "glue" interfacing to their blob.), what matters is the external API/ABI between the kernel and userspace, and that is quite stable (at least the ABI, the API does change a bit.)

Re:Change to the ABI

[petermgreen]

indeed the general purpose userspace API/ABI is pretty stable though newer glibc versions have started to depend on 2.6 (most notablly NPTL), I assumed that the broke the ABI comment was in reference to the modules APIs.

Re:PWRficient support?

[Wesley Felter]

PowerPCs tend to be less than 100% compatible with each other, mostly because there is not a huge legacy of OSes that must be carried forward (e.g. people expect the latest and greatest x86s to boot DOS and Win95, but nobody exepcts some random old kernel to run on a new embedded PPC). Also, the PWRficient is a SoC with several new on-chip devices.

But why?

[camperdave]

change /dev/hd?? to /dev/sd?? (even with IDE)

Why was this done, though? All my IDE drives changed from hd? to sd? and for a while I couldn't boot. I had to rewrite my entire fstab. Parallel ATA may be going the way of the dodo, but it's far from dead.

do I really care?

[nanosquid]

I think since 2.6 has come out, I have lost complete track of kernel versions--it simply doesn't matter anymore to me. I think at this point, people could come in and replace the Linux kernel with BSD, Darwin, or Solaris and I probably wouldn't notice. Kernels have become a commodity.

Re:do I really care?

[petrus4]

I'm assuming you have totally bland vanilla hardware then. Linux's support for diverse hardware is still quite a long way ahead of FreeBSD, at least it was last time I looked, and that was 6.2-RELEASE.

Re:do I really care?

[DrJokepu]

I don't know about BSD or any other Unices/Unix-clones but the Solaris kernel doesn't support virtual terminals right now as Linux does, you would definitely notice that if you use console a lot. BTW, am I the only one who thinks that X terminals suck?

Re:do I really care?

[dbIII]

I think at this point, people could come in and replace the Linux kernel with BSD, Darwin, or Solaris and I probably wouldn't notice

True in some cases and very good - we are finally getting to the point where a lot of decent software is cross platform.

Re:do I really care?

[howlingmadhowie]

i think what has happened, is that kernels have become free and good. how many years to you have to go back before solaris cost hundreds of dollars and free/openBSD wasn't any good? the ability to share code inherent in opensource projects is a prerequisite for choice.

Re:do I really care?

[nanosquid]

My motherboard has a bug that makes using the console unpleasant, so I stopped using virtual consoles a few years ago and I don't miss them anymore.

There are probably a dozen different terminal emulators for X11; I use rxvt, xterm, and gnome-terminal, and they seem pretty much interchangeable to me.

Options?

[xealot]

What might those options be? I have a Dell Inspiron which runs 2.6.17 fine, then I tried to compile and boot 2.6.20 and got Kernel Panic. The kernel that comes with Feisty Fawn does something similar. To install Edgy Eft originally I had to pass pci=nomsi so the SATA hard disk would work, which I supposedly don't need to pass ever again...
Anyway, I've tried compiling that kernel a few times with SATA stuff compiled in rather than modular and every time I boot it I get a Kernel Panic. I still have to use 2.6.17-11 on Feisty Fawn. I'm not that annoyed yet, but if every subsequent kernel does this I will be very pissed.

Re:Does it still crash after 49.7 days??

[TheThiefMaster]

I'll accept your funny problems and raise you another:
AMD K6/2 too fast for Windows 95: News MS Support

My own wishlist

[mangu]

I'd like to have some form of force feedback running. Yes, I know, this is a device driver issue, not a kernel one, but the drivers come with the kernel. My Microsoft Sidewinder wheel is the only reason why I still keep a Windows partition at home.

Does anybody there know a wheel that has good force feedback features in Linux? If I had one I would start contributing code to some project like torcs or rars.

Re:EXTRA EXTRA!

[number1scatterbrain]

I know that's you, Ballmer. Anonymous, my ass!

Yep

[StarKruzr]

Read that article, but don't really understand the reasoning.

To me, it makes it appear as though nothing "really major" as changed in the kernel since 2.6.0, when, of course, nothing could be further from the truth.

Re:Yep

[arodland]

It doesn't make it appear that way if you stop insisting that it does. See? Problem solved. :)

No, it's just the hardware

[mangu]

people could come in and replace the Linux kernel with BSD, Darwin, or Solaris and I probably wouldn't notice.

This means your CPU is much more powerful than what you really need. I used FreeBSD a bit in the 1990s, but switched to Linux because the kernel allowed me better fine tuning in the 486 CPU I had at the time.

Today the CPU is way over my needs too, but I stick to Linux because, first, I have no need to switch and, second, Linux has better hardware support than the others you mentioned.

Re:OMG F1r5t P054

[MoOsEb0y]

6 digit (l)user :P

Re:PWRficient support?

[Grishnakh]

It doesn't work that way outside of x86-land. As another responder said, the PWRficient isn't just a CPU, it's a SoC (System on Chip). To compare to an x86 system, that would be like having a low-power CPU, north bridge, south bridge, SATA controller, ethernet controller (but not PHY), memory controller, I2C interface, USB controller, interrupt controller, etc. all wrapped up on one chip. This is quite common in the embedded world, where most PPCs are used these days (I'm working on one myself in my day job).

Since each SoC is totally different, except maybe for the CPU core, porting Linux (or any OS) to it is a little more difficult than just compiling it and loading it. Check out the arch/ppc or arch/arm directories for examples of all the different chips supported. While the work certainly isn't comparable to, say, porting Linux to an entirely different CPU architecture, it does require several new files with custom code to support things like the way interrupts are assigned to the specific functions on the SoC.

Worse, sometimes new drivers need to be written for certain on-chip peripherals, because some bonehead empire-building managers at the chipmaker wanted to justify a higher budget for their department by, instead of just re-using an existing USB controller or Ethernet controller design and plopping that onto the chip, putting together a whole team and spending months creating a new controller because it might improve performance by a whopping 5%. My last company, which made a lot of ARM-based chips, was especially guilty of this.

Right, brothers...

[Slashcrap]

But apart from virtualization with VMI, paravirtualization, live migration and host suspend/resume supportsupport for kvm, a tickless idle loop mechanism with unified high resolution timer handling, bigger kernel parameter-lines, support for the PA SEMI PWRficient CPU and for the Cell-based 'celleb' Toshiba architecture, NFS IPv6 support, IPv4 IPv6 IPSEC tunneling, UFS2 write, kprobes for PPC32, kexec and oprofile for ARM, public key encryption for ecryptfs, Fcrypt and Camilla cipher algorithms, NAT port randomization, audit lockdown mode, some new drivers and many other small improvements, what has Linus ever done for us?

Re:Right, brothers...

[enchanter1001]

Splitter! *ahem* enchanter

Camilla cipher = Camellia cipher?

[bratgitarre]

Is it just me, or did they misspell the name of the cipher? The only cipher of a similar name I found was Camellia, developed by NTT and Mitsubishi (and Sony?): http://info.isl.ntt.co.jp/crypt/eng/camellia/index .html I had never heard of it, so I was wondering why the kernel team decided it's worth being included already (both in terms of small user base and unknown security). Turns out it's in the European NESSIE standard, and there's an RFC. More on Wikipedia: http://en.wikipedia.org/wiki/Camellia_(cipher)

Where is - REISER4 - the BEST FILESYSTEM ever.

[Anonymous Coward]

REISER4 - THE BEST FILESYSTEM EVER.

You can read more here:

http://linuxhelp.150m.com/resources/fs-benchmarks. htm
http://m.domaindlx.com/LinuxHelp/resources/fs-benc hmarks.htm

| FILESYSTEM | TIME |DISK |
| TYPE |(secs)|USAGE|
 
|REISER4 lzo | 1938 | 278 |
|REISER4 gzip| 2295 | 213 |
 
|REISER4 | 3462 | 692 |
|EXT2 | 4092 | 816 |
|JFS | 4225 | 806 |
|EXT4 | 4408 | 816 |
|EXT3 | 4421 | 816 |
|XFS | 4625 | 779 |
|REISER3 | 6178 | 793 |
|FAT32 |12342 | 988 |
|NTFS-3g |10414 | 772 |

Column one measures the time taken to complete the bonnie++ benchmarking test (run with the parameters bonnie++ -n128:128k:0). The top two results use Reiser4 with compression. Since bonnie++ writes test files which are almost all zeros, compression speeds things up dramatically. That this is not the case in real world examples can be seen below where compression does not speed things up. However, more importantly, it does not slow things down either.

Column two, Disk Usage: measures the amount of disk used to store 655MB of raw data (which was 3 different copies of the Linux kernel sources).

OR LOOK AT THE FULL RESULTS:

|File |Disk |Copy |Copy |Tar |Unzip| Del |
|System |Usage|655MB|655MB|Gzip |UnTar| 2.5 |
|Type | (MB)| (1) | (2) |655MB|655MB| Gig |
 
|REISER4 gzip | 213 | 148 | 68 | 83 | 48 | 70 |
|REISER4 lzo | 278 | 138 | 56 | 80 | 34 | 84 |
|REISER4 tails| 673 | 148 | 63 | 78 | 33 | 65 |
|REISER4 | 692 | 148 | 55 | 67 | 25 | 56 |
|NTFS3g | 772 |1333 |1426 | 585 | 767 | 194 |
|NTFS | 779 | 781 | 173 | X | X | X |
|REISER3 | 793 | 184 | 98 | 85 | 63 | 22 |
|XFS | 799 | 220 | 173 | 119 | 90 | 106 |
|JFS | 806 | 228 | 202 | 95 | 97 | 127 |
|EXT4 extents | 806 | 162 | 55 | 69 | 36 | 32 |
|EXT4 default | 816 | 174 | 70 | 74 | 42 | 50 |
|EXT3 | 816 | 182 | 74 | 73 | 43 | 51 |
|EXT2 | 816 | 201 | 82 | 73 | 39 | 67 |
|FAT32 | 988 | 253 | 158 | 118 | 81 | 95 |

Each test was preformed 5 times and the average value recorded.
Disk Usage: The amount of disk used to store the data (which was 3 different copies of the Linux kernel sources).
The raw data (without filesystem meta-data, block alignment wastage, etc) was 655MB.
Copy 655MB (1): Copy the data over a partition boundary.
Copy 655MB (2): Copy the data within a partition.
Tar Gzip 655MB: Tar and Gzip the data.
Unzip UnTar 655MB: UnGzip and UnTar the data.
Del 2.5 Gig: Delete everything just written (about 2.5 Gig).

http://lkml.org/lkml/2007/4/9/4

Re:Where is - REISER4 - the BEST FILESYSTEM ever.

[SirTalon42]

A very, very, very long ways away from being merged into mainline. About a year ago I tried running Reiser4 as my root filesystem on my laptop for a good while. I had quite a few issues because of it as well, also the performance was pretty crappy. Now I've switched my laptop over to version 3, which I had been running on my desktop for a very long time and have had a much more pleasant experience.

Reiser4 has a very interesting design (I find the plugin approach interesting), but in practice the implementation just wasn't there yet from my usage of it.

Like shooting fish in a barrel

[El_Oscuro]

I mean, picking on Microsoft for stuff like this is like adding a Windows computer to your botnet. Kind of fun, but gets boring after awhile.

On the other hand, Oracle can write crappy code with the best of them. I'll see you and raise you again.

At least the title wasn't

[tropicflite]

Ubuntu Kernel 2.6.21 Published

Language

[StarKruzr]

does not an arbiter of a versioning system make. :p

More things have changed between 2.6.0 and 2.6.21 than changed between 2.0 and 2.2.

How's that?

Changes that affect normal users?

[Danathar]

It could be that the LINUX kernel is entering a stage of it's life where each release will not really be revolutionary. I used to read about new ideas that actually made a difference in the user (desktop user) experience.

Now it seems it's all about virtualization. Don't get me wrong, I love virtual machines and such. It's just that there does not seem to be any new revolutionary ideas like the new swap mechanism some years back that did help performance out.

Side by side, with a reasonable set of controlled variables (compiler, settings, etc) is the Linux kernel any faster executing my program than say the windows kernel? FreeBSD?

Seems developers are more interested in features than improving performance. Unless like I said before nobody thinks there is much more improvement in performance and efficiency to be had.

Re:Changes that affect normal users?

[Tim_UWA]

I know that this is a terrible comparison, but I found that running code on Mathematica on Windows takes a lot longer than it did on Windows (for numeric tests, I chose not to compare graphics-related tasks). That was about a year ago (I only run Windows in VMWare now, so I can't make any more fair comparisons).

Re:Changes that affect normal users?

[Assembler]

Seems developers are more interested in features than improving performance.

A tickless kernel gives the scheduler much finer control, and down the line will probably improve performance.

http://lwn.net/Articles/223185

Re:Changes that affect normal users?

[spikedvodka]

run that by me again:
but I found that running code on Mathematica on Windows takes a lot longer than it did on Windows

You compared something to itself and got different results?

Re:Changes that affect normal users?

[bratwiz]

A tickless kernel gives the scheduler much finer control, and down the line will probably improve performance.

And keeps it safe from Lime's disease as well...

Re: Changes that affect normal users?

[r_jensen11]

Or it could just be that the kernel developers have been keeping up with major hardware issues lately and that there hasn't been a major new piece of hardware introduced since the last kernel release. Of course, if nVidia or ATI would break their contracts with whatever parties they worked with to make their video drivers and suddenly opened everything up, then that would be revolutionary. But as it is, we already have Cell drivers, most hardware components work, etc. The improvements pretty much need to be along the lines of stabilizing and improving HAL, dbus, and other software.

Linux hibernate support

[canadiangoose]

Linux has amazing hibernation support. I use some software called Suspend2 on my laptop, and it works like a charm. It was a little difficult to get it going the first time, but now that it's installed I find it very fast and reliable. It doesn't even require any special support from the hardware!

Re:Does it still crash after 49.7 days??

[Assembler]

It wraps after 49.7 days on kernels with a faster tick rate than yours.

Re:Does it still crash after 49.7 days??

[Assembler]

Your timer frequency must be set to 100HZ. The default for 2.6.20 was 1000HZ, and thus wraps at 49.7 days. Other settings are 250 and 300 HZ.

Re:Does it still crash after 49.7 days??

[AaronW]

As I said, it is running 2.4.20. The rollover problem was fixed in 2.4.21 so 2.6 should not have this issue.

Celleb?

[ja]

The Toshiba Celleb Architecture ... Now this is a new word in my vocabulary. Anybody knows what this "Celleb" is and where to get one?

Re:Celleb?

[wild_berry]

I assume that's Cell broadband engine in Endian Big mode.

if you want to speed startup

[alizard]

in Debian (Ubuntu?) open /etc/init.d/rc AS ROOT and change concurrency=none to concurrency=shell . Worked for me... of course, usual disclaimers, if you do this and your computer melts into slag from which Cthulhu appears and eats you, I'm not respons..........[i0m =09=,k9mu9n8yby7ba70tyc7 n=0987 NO CARRIER

CFS not included?

[togashi06]

Wasn't CFS( the new dispatcher) going to make it for this release?

MS Ergonomic 4000?

[remmelt]

How come there is still no support for the Microsoft Natural Ergonomic Keyboard 4000, as they call it? It's the best "broken" keyboard out there and one of the most comfortable ones I've ever used. Patches have been submitted multiple times, and seem to be maintained... No love for this hardware.

First couple of Google hits:

http://lkml.org/lkml/2006/8/3/80
and
http://lwn.net/Articles/194015/
or
http://gentoo-wiki.com/HOWTO_Microsoft_Natural_Erg onomic_Keyboard_4000
or
http://doc.gwos.org/index.php/Microsoft_Natural_Er gonomic_Keyboard_4000

And no, I don't want to recompile my kernel.

Re:MS Ergonomic 4000?

[bratwiz]

They've been holding the driver code hostage. They'll release it when Microsoft fixes its dual-boot...

Re:PWRficient support?

[rbanffy]

I think every recent voting machine in Brazil uses a Geode, which is a more modern take on the MediaGX.

It was not very successful on the desktop, but on the embedded x86 market, it's a hit.

And yes, if I segment the market enough (embedded less than 20 watt 32 bit x86 used mostly on weekends) just about every processor can become a hit. ;-)

what happens if the source or dest host crashes?

[t35t0r]

With KVM 1.5 what happens when:

1) A VM has migrated its process to another VM and the source VM crashes/system dies?
2) A VM has migrated its process to another VM and the destination VM crashes/system dies?

Re:PWRficient support?

[bensch128]

Worse, sometimes new drivers need to be written for certain on-chip peripherals, because some bonehead empire-building managers at the chipmaker wanted to justify a higher budget for their department by,

This is what my company does as well because when you expect to ship so many units that the per-unit cost is much more important then the development costs so it makes sense to do everything possible to minimize the per-unit cost. The upshot of this is that it causes my company to employ one kernel hacker and several kernel consultants, all working on the mainline kernel.

Cheerio
Ben

Re:PWRficient support?

[Grishnakh]

There's no good reason for a CPU like this in a desktop system; the CPU itself is far too slow for desktop apps, and the design isn't flexible enough to allow picking and choosing components.

If a SoC made sense in desktop systems, it would have already been done.

Re:Does it still crash after 49.7 days??

[sirfuzz]

Really? Mine doesn't roll over:

# uptime
  13:41:05 up 500 days, 22:59, 1 user, load average: 0.34, 0.23, 0.24

Re:PWRficient support?

[Grishnakh]

Employing a bunch of hardware engineers to create a new core does NOT minimize per-unit cost, it adds to it.

The only way it would minimize cost is if the alternative is licensing a core from someone else, which incurs a per-chip royalty.

In my situation, the company already had pre-existing cores ready to use. Instead of just reusing their own IP, they created whole new cores to satisfy some manager's ego, because they supposedly might get 5% better performance (and on a peripheral part like a USB controller, who cares?).

Homegrown solutions are great so you're not beholden to other companies or vendors. But if you already have something that works and is free, you don't need to reinvent the wheel.

Re:PWRficient support?

[bensch128]

Employing a bunch of hardware engineers to create a new core does NOT minimize per-unit cost, it adds to it.

It does if each unit will be more profitable then before. This is a game for accountants but generally you plan on selling enough units to offset the upfront development costs, then it makes sense to make each unit as profitable as possible.


In my situation, the company already had pre-existing cores ready to use. Instead of just reusing their own IP, they created whole new cores to satisfy some manager's ego, because they supposedly might get 5% better performance (and on a peripheral part like a USB controller, who cares?).

Oh, well that's a totally different issue. Maybe he thought it would be more profitable...

Cheerio
Ben

Re:Does it still crash after 49.7 days??

[Assembler]

Ah.. On newer kernels, the system's uptime command will report the correct uptime, but Netcraft won't.

http://uptime.netcraft.com/up/accuracy.html#hz1000

Why do you not report uptimes for Linux 2.6 or FreeBSD 6 ?

We only report uptimes for systems where the operating system's timer runs at 100Hz or less. Because the TCP code only uses the low 32 bits of the timer, if the timer runs at say 1000Hz, the value wraps around every 49.7 days (whereas at 100Hz it wraps after 497 days). As there are large numbers of systems which have a higher uptime than this, it is not possible to report accurate uptimes for these systems.

My favorite thing

[StarKruzr]

about this thread is that I got modded down to -1, Offtopic and then back UP to 0 for being funny.

lol. just pure lol.

lol!

[StarKruzr]

Also, you avoid answering some questions you were asked!

That is not a strong suit for you either. Are you jewish or not?

The fact that you cannot comprehend how incredibly bizarre it is that you keep asking me this is a source of no end of funnies to me.

Holy shit, you are SERIOUSLY unhinged.

[StarKruzr]

Why did you post the same in(s)anity 10 times in a row at WITPro? What is wrong with you? Does narcissism include the need to repeat yourself over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over and over?

This paragraph exists to defeat the Slashdot "lameness filter," because sometimes repetition is necessary to make a point. Apparently that escapes those who wrote Slashcode. Although really, it's understandable, since without this test you'd just have people spamming page upon page of "GNAA 4 LYFE" ad infinitum, everywhere.

LINUX 2.6.21

[Grindalf]

Gulp, free BSD are getting behind...

Hm, I wonder!

[StarKruzr]

Do you think Slashdot has the ability to search for comments by a user further back than what's viewable on his userpage?

I do.

Just something to think about.