New kernel 2.6.38-rc1. Anyone tried it?

loldog

Apparently it's got some MAGIC coded into it.

http://www.phoronix.com/scan.php?page=news_item&px=OTAyNw

The RCU-based path name lookup is Torvalds' other favorite feature. "The RCU-based name lookup is at the other end of the spectrum - the absolute anti-gimmick. It's some seriously good stuff, and gets rid of the last main global lock that really tends to hurt some kernel loads. The dentry lock is no longer a big serializing issue. What's really nice about it is that it actually improves performance a lot even for single-threaded loads (on an SMP kernel), because it gets rid of some of the most expensive parts of path component lookup, which was the d_lock on every component lookup. So I'm seeing improvements of 30-50% on some seriously pathname-lookup intensive loads."

It's the first time I compiled a kernel and I didn't notice anything special about it, until I loaded up Flightgear. Then I noticed an amazing difference, the CPU usage in top is down from 90% to 46% or so. A huge difference. I'm still using the Nvidia 260.19 driver.

If you're using Ubuntu you can download .debs for it from here:

http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.38-rc1-natty/

If you want to undo, just remove them in Synaptic.

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Bluefrog

Had read about this a while back and when I saw your post went and grabbed the debs and installed.

Don't see huge performance benefits for day to day computing but I was having issues with the ati mobility card I have with sound distortion when I payed video in fullscreen and that is no longer a problem which I am very pleased about.

pickarooney

I'm tempted to try this to see will it fix my sound problems.

Bluefrog

Well you don't have much to lose using the Debs with Ubuntu - can just uninstall them if you get bad results.

Bluefrog

Just ran into an issue using this kernel in that the vbox kernel drivers won't load and I can't seem to compile them against this kernel following the instructions in the error dialog that displays when I try to run a virtual machine.

Will take a look around for a fix for this but probably not a deal breaker for most people.

Have had no other issues so far.

Bluefrog

This issue seems to be down to the .h files in the vbox source folder having an incorrect include line. The following fixes it:

sudo find /usr/share/virtualbox/src/vboxhost -name *.h -exec perl -pi -w -e 's/linux\/autoconf/generated\/autoconf/g;' {} \;
sudo /etc/init.d/vboxdrv setup

Happy days.

loldog

rc2 is out now:

http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.38-rc2-natty/

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