The Linux 2.6.31 kernel is still under active development until it is released later this quarter, but the merge window is closed and most of the work going on is to address bugs and other regressions within this massive code-base. Some of the key additions to the Linux 2.6.31 kernel include many graphics-related advancements (merging of the TTM memory manager, Radeon kernel mode-setting, Intel DisplayPort, etc), an ALSA driver for the Creative X-Fi, initial USB 3.0 support, file-system improvements, and much more. To see how the general system performance has been impacted by the new Linux kernel that is in development, we have a few benchmarks today.
Same here. I am running 2.6.31rc2 on my eeepc (because it helps a lot with the Intel IGP). But boot time to a full KDE4 login (mostly reads from the ext4 fs on the SSD) went up from 86 secs to 105 secs or so. All this in Kubuntu 9.04.
I hope these fs regressions get worked out before the kernel goes golden!
Well pure rc2 is not that good, you need extra patches to make dm work or to compile with older gcc. Also vbox 3 as host has issues on some systems (somehow not all). I did not notice speed diverences yet as i did not do any benchmarks. Basically it is possible to build fglrx with patches without modifiying the kernel too, i just don't know if my patch is fully correct. At least i did not notice any extra problems over those already known when using fglrx 9-6 with 2.6.29+.
I am using a custom-built image of 2.6.31-rc2 on Kubuntu Karmic alpha. With all of the drivers for the hardware I need compiled in (Literally, the only thing in the output of lsmod is nvidia) and all the stuff I dont need removed, it takes about 11 seconds to boot from scratch to KDM. Then, it takes another 30 or 35 to start KDE. (Somehow, it starts taking this long whenever I modify or remove the Network Manager plasma widget after installing.)
Nice, did you configure that by hand & trial and error or did you use some kind of a tool?
By hand, every bit of it :-) I started with the Ubuntu kernel configuration, then I changed the CPU settings to fit my system better (optimized for Core 2/later Xeon, SMT support off, AMD support off, etc) and then I went through set the drivers for all of my hardware to be compiled in, and I disabled a bunch of stuff I thought I would never use. It booted up the first time, but there were a few more modules I compiled in after that.
You gain only compile time when you disable unused modules and a bit hd space. Your pc will not get faster that way. The different cpu optimization gives you basically no speed increase, maybe in some rare cases. You "feel" changes like a different sheduler but no optimisation settings. Btw. KDE 4 starts really slow, when you would test my own distro with KDE 3.5 as development version then you would see that. Kubuntu is very easy to beat in bootup time.
I didn't expect to gain much speed by recompiling. My primary objective was to make the system boot faster, which I accomplished. By the way, I also changed from "Voluntary Preemption" to "Preemption" which makes my system respond better when under load. (So well, in fact, that sometimes I have trouble telling it is under load without looking at top.) And having a shorter compile time is nice, too. A stock Ubuntu kernel takes almost an hour to compile on my machine, if I remember correctly. Mine takes only 20 or 30 minutes. I know my startup is slow, it is because I have removed the default Plasma Widget Network Manager because it does not work. Whenever I do this, the system gets some configuration problem, and refuses to start quickly anymore.