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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."
And I just upgraded to 2.6.20-15! (Kubuntu Feisty Fawn)
"We may face a scorched and lifeless earth, but they're accountable to their shareholders first."
I haven't been able to get anything past 2.6.17 to boot successfully, I think they seriously hosed the ATA shit.
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.
"Sometimes, I think Trent just needs a cup of hot chocolate and a blankie." -Tori Amos on Nine Inch Nails
... but does it run Linux?
Once again, it took many months of work to optimize an idle loop.
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.
Ewige Blumenkraft.
Here.
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.
There is no reasonable defense against an idiot with an agenda
:wq
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?
+++ATH0
You're confusing Linux with this Windows 95/98. However, this problem or this another problem are even more funnier
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
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)
"-1 Troll" is the apparently the same as "-1 I disagree with you."
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.
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. :-)
Assorted stuff I do sometimes: Lemuria.org
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.
497 day wrap around? You should switch to Windows. I'm sure no such problem has ever been reported on that OS.
Slow down, cowboy! It has been 4 hours since you last posted. You must wait another few hours.
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.
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In other news, eCryptfs has recently been given the go-ahead for inclusion into Fedora:
https://bugzilla.redhat.com/bugzilla/show_bug.cgi
In the meantime, you can grab all the userspace stuff from the eCryptfs SourceForge site:
http://ecryptfs.sourceforge.net/
An unjust law is no law at all. - St. Augustine
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.
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I know that's you, Ballmer. Anonymous, my ass!
Remember the future...
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.
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.
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.
The common sense of the US Government is the only thing standing between us and DRM hell? Oh dear :(
I mod down anyone who says "I will be modded down for this", regardless of the rest of their comment