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

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.

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: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. :-)

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/