Linux 2.6.32 Kernel Benchmarks

[phoronix]

Phoronix: Linux 2.6.32 Kernel Benchmarks

With the Linux 2.6.32 kernel being released in a few days, we found it time to benchmark this newest kernel release that brings new drivers, kernel mode-setting improvements, virtualization enhancements, and more.

http://www.phoronix.com/vr.php?view=14403

[hax0r]

I'm starting to think that those big boys should really start testing and profiling their crap. I wonder how 2.6.24 would compare. Good article.

[blackshard]

I'm starting to think that those big boys should really start testing and profiling their crap. I wonder how 2.6.24 would compare. Good article.

I asbolutely quote here.

[kraftman]

I'm starting to think that those big boys should really start testing and profiling their crap. I wonder how 2.6.24 would compare. Good article.

They actually do, but they also do proper benchmarks. I wonder if generic kernels were tested here and still ext4 vs different mount options (or mentioned commit which changed behavior) and maybe even different settings like NO_NEW_FAIR_SLEEPERS which is default in Karmic and it affects benchmarks numbers. Btw, what are you talking about if it was planned change?

And like Michael pointed:

The very significant drop in PostgreSQL's performance in the Linux 2.6.32 kernel with default options can be attributed to this lone Git commit that is for a fix to address cache flushing in ext4_sync_file for the EXT4 file-system. This commit improves data integrity in the event of a power loss or other problem, but carries a high disk performance penalty.

[Luis]

It should be noted than on 2.6.32, both the CPU and the I/O schedulers have been tuned for desktop usage (i.e, low latency), which means a drop in throughput in many cases. But desktop users should "feel" things faster, more responsive.

So nothing to worry about here, on the contrary, it just proves that the kernel devs did a bold movement in favour of desktop users.

[kraftman]

It should be noted than on 2.6.32, both the CPU and the I/O schedulers have been tuned for desktop usage (i.e, low latency), which means a drop in throughput in many cases. But desktop users should "feel" things faster, more responsive.

Yes, but I/O scheduler will be probably set for throughput for final 2.6.32. Afaik it's set for low latency in -rc and some benchmarks suffer from this. It should be optimized and set default for 2.6.33.

So nothing to worry about here, on the contrary, it just proves that the kernel devs did a bold movement in favour of desktop users.

Yes, if someone wants to have good results in some benchmarks just mount file system using different mode or options.

[Apopas]

I wonder if this boost is just for x264 or if we are gonna see sweet results with lame and oggenc as well

[kraftman]

Yes, but I/O scheduler will be probably set for throughput for final 2.6.32. Afaik it's set for low latency in -rc and some benchmarks suffer from this. It should be optimized and set default for 2.6.33.

I/O scheduler is set for low latency in the final 2.6.32 and this can have impact on some benchmarks. From kernel newbies:

In this release, the CFQ IO scheduler (the one used by default) gets a new feature that greatly helps to reduce the impact that a writer can have on the system interactiveness. The end result is that the desktop experience should be less impacted by background IO activity, but it can cause noticeable performance issues, so people who only cares about throughput (ie, servers) can try to turn it off echoing 0 to /sys/class/block/<device name>/queue/iosched/low_latency. It's worth mentioning that the 'low_latency' setting defaults to on.

http://kernelnewbies.org/LinuxChange...231eaf58a63ed8

[Apopas]

This x264 boost is rather interesting, but this postmark and iozone regressions are due to the ext4 "problem"?

[Ant P.]

This x264 boost is rather interesting, but this postmark and iozone regressions are due to the ext4 "problem"?

No idea what's wrong with ext4, but Con Kolivas needs three cheers for getting them to finally fix their damn scheduler.