Linux Kernel 2.6.24 Released

LinuxFan writes "Linus Torvalds has released the 2.6.24 Linux Kernel, noting that he and most of the other key Linux developers will be flying to a conference in Australia for the next week. As the whole team will be down under while the kernel is being tested by the masses, Linus added, "Let's hope it's a good one". What's new in the latest release includes an optimized CFQ scheduler, numerous new wireless drivers, tickless kernel support for the x86-64 and PPC architectures, and much more. Time to download and start compiling."

Wow. Lots of stuff.

[MostAwesomeDude]

On one hand, things like the VM dirty writeback adjustments and default cpufreq frequency governors, as well as dynticks for more arches, are big performance improvements. On the other hand, they broke wireless packet injection patches for a lot of drivers... At any rate, I'll have to try this just to see if it really performs better. Things like laptop_mode which rely on optimized scheduling and writeback code should see improvements.

Merge Window?

[AndGodSed]

"Since I already had two kernel developers asking about the merge window and whether people (including me) traveling will impact it, the plan right now is to keep the impact pretty minimal. So yes, it will probably extend the window from the regular two weeks, but *hopefully* not by more than a few days."

Now THERE's confidence for you. Great news.

Still no orinoco monitor mode

[Anonymous Coward]

The orinoco wireless drivers have supported monitor mode since 2004. Still not in the kernel today. Do any of the BSDs support monitor mode yet on this incredibly well documented chipset? I'll migrate if the answer's yes.

Catching up to Windows on power

[dpilot]

From everything I've heard, Linux is still only catching up to Windows in terms of power consumption. It's fun because we hear all of the details, and until someone builds some nifty package, we script all of the dial-tweaks ourselves. Part of the fun is knowing the dials and what they do, but I guess that's not fun for everyone, some want it to just work, and we're getting there. As long as I can still see the dials, understand them, and tweak them, good automated default power management is good, too.

But from a methodology viewpoint, does anyone understand the road Windows has trod, and how they have gotten to where they are? For instance, things like the tickless kernel are pretty fundamental. Is the Windows kernel tickless, or how do they get their power down if it isn't?

Re:I am really grateful for this release

[ajs318]

Let us also digress into a micro-kernel vs monolith-kernel discussion.

Oh, that's an easy one. With a microkernel, you put up fences where they look pretty. With a monolithic kernel and loadable modules, you put up fences where as little stuff as possible has to traverse them. Ting! Next, please.

Re:tickless kernel support?

[Andy Dodd]

There is another patch that adds high resolution timers to Linux. (Actually, another component of a gigantic patchset that has been rapidly getting mainlined over the past few kernel releases.)

I think CONFIG_HRTIMERS is already an option (may not default to on though). If it isn't, go find the RT_PREEMPT patchset. That includes (or if HRTIMERS is in the kernel, included) HRTIMERS, it's also where the NO_HZ option came from.

Re:Catching up to Windows on power

[ThePhilips]

It is sad reality the people keep mixing up technology and products.

Linux (as kernel and piece of technology) is far ahead of most OSs in power management and especially in power saving.

But. Take fresh Windows XP installation - it would give you decent up-time from single battery charge. Take Mac OS X - it would give you excellent up-time from single battery charge. Now take Linux's distro with X.Org/GNOME/KDE/etc - and it would eat any battery in under two hours.

It is possible to optimize Linux to be extremely power efficient, yet lion share of applications written for PCs simply fail on portables.

From recent example. I'm reading lots of PDF ebooks - under Mac OS. Trick is to scroll document to the end and then go back to place were you stopped: Mac OS would cache the file and hard drive will not wake up for the whole time you read thru the PDF. Linux? - Ubuntu/Kubuntu/SUSE/YellowDog were tried - hard drive is always spinning. Always. Non-stop. I stopped even trying to investigate what keeps it spinning - just went back to Mac OS. Because battery lasts under Linux for about 2 hours - while Mac OS on the aging iBook easily does 6 hours. But honestly, even if battery charge set aside, the noise produced by constantly spinning hard drive me slowly crazy.

Conclusion: excellent power management of kernel != end-user application are designed with power efficiency in mind.

P.S. Most common offenders are X.Org with its ~/.xsession-errors (as if end-users cared about all the cruft in there - developers simply do not look there at all) and syslogd which periodically (by default every 20 minutes) write marker into logs.

Re:I am really grateful for this release

[0xABADC0DA]

With a typesafe kernel like monotone or jxos everybody has a personal force field bubble around them that nothing crosses, and they just point at stuff outside their bubbles. Also, there are no laws because the force fields keep everybody perfectly safe all the time.

Re:Catching up to Windows on power

[MostAwesomeDude]

Go grab laptop-mode-tools (I guarantee it's available for your distro) and a kernel newer than 2.6.10, and then enjoy. Among other things, your hard drive will only spin up once every 10 minutes at most if you're not requesting reads or writes. It's possible to beat Windows in battery usage very easily -- Windows can't do things like power down the USB buses if there's nothing connected or requesting power, or sleep the CPU for 99% of its ticks.