The 2.6.38 kernel's "wonder patch"

[gradinaruvasile]

It seems to be working just as advertised - you have to open your cpu hungry stuff in different terminals though to take advantage of its power.
Edit: maybe launching programs with setsid has the same result, maybe someone can enlighten me about it...

AND enable it - it is disabled by default:

sysctl kernel.sched_autogroup_enabled=1

Disabling it:

sysctl kernel.sched_autogroup_enabled=0

I use the 2.6.38-2-686-bigmem kernel from experimental (4 GB RAM) on an Athlon II x2 250 @3.00 GHz CPU.
I compiled Wine with "make -j 20" (that are 20 parallel threads) and i did not feel it on my desktop/browsing tasks.
With that above value set to 0, i had very slow desktop redrawing, extremely slow program launch - opening a gnome-terminal for example took a few seconds, whereas with it enabled it is instant.
BTW on previous kernels such as the 2.6.32 i remember trying the exactly same command (make -j 20 on wine) and it led to complete desktop lockup after 15-20 seconds - so the 2.6.38 kernel has some other tweaks that help in this area.

[Tadeas]

Well, the "wonder patch" is the reason why I've used 2.6.38 since -rc1. It worked great by then, it works great now! The difference is obvious. This is what I love about open source - you get great upgrades very often. When did Windows users get an enhancement like this last time?

BTW it's enabled by default if you enable it when compling

[kevin01123]

Works great. Compiled 2.6.38.2 on Squeeze just now. Compiled emacs, xulrunner, and linux-mainline while surfing youtube to test it. No slow downs what so ever.

[dark_stang]

You guys are making me compile a new kernel...

[kevin01123]

Not only that, but I've noticed a general performance improvement overall compared to the stock squeeze kernel.

[hellfire[bg]]

Is this patch enabled by default? Will "kernel.sched_autogroup_enabled=1" work on a stock debian kernel?

[kevin01123]

cat /proc/sys/kernel/sched_autogroup_enabled

If 1, it's enabled. If 0, then it's not. I don't know how to enable it on a stock kernel. I compiled the functionality into mine.

[eric1959]

Code: Select all

$ cat /proc/sys/kernel/sched_autogroup_enabled
1
$uname -r
2.6.36-1.dmz.1-liquorix-amd64

http://liquorix.net/

[hellfire[bg]]

kevin01123, i understood how to enable it. My question was if it was enabled by default on the stock debian kernel or i should compile my custome kernel.

[gradinaruvasile]

kevin01123, i understood how to enable it. My question was if it was enabled by default on the stock debian kernel or i should compile my custome kernel.

I use the 2.6.38-2 debian kernel installed from experimental. The task grouping is disabled by default, can be enabled with

sysctl kernel.sched_autogroup_enabled=1

No need to compile. You can put that line in /etc/sysctl.conf.

[manmath]

You guys are making me compile a new kernel...

I saw kernel 2.6.38 (http://darkstang.com/repo/binary/linux- ... _amd64.deb) in the repo mentioned in your signature. Will that install well and work on Debian squeeze?

[dark_stang]

You guys are making me compile a new kernel...

I saw kernel 2.6.38 (http://darkstang.com/repo/binary/linux- ... _amd64.deb) in the repo mentioned in your signature. Will that install well and work on Debian squeeze?

It works all right for me on Debian Unstable. If you want to use it feel free, there are also 2.6.38 images in the official Debian Unstable repo if you'd prefer one of them.

Edit: Note, that kernel doesn't have the automatic process grouping enabled though. A new one that I'm making will. I think the ones in the Debian sources already do.

[sidRo]

I use the 2.6.38-2 debian kernel installed from experimental. The task grouping is disabled by default, can be enabled with

sysctl kernel.sched_autogroup_enabled=1

No need to compile. You can put that line in /etc/sysctl.conf.

Doesn't work.

kernel variable sysctl kernel.sched_autogroup_enabled=1 unknown ...

[vbrummond]

I think it is a good start but far from a wonder, especially for an average user. Currently I do not feel it offers me much that a simple "nice make -j 4" does not do already. The only strength I see of it is that it is automatic. Perhaps in the future they may have better parameters for splitting the jobs? Me, for now I will turn off cgroups and just nice anything I do not want to bother my foreground work.

I am quite sure if you download the debian 2.6.38-2 sources or if you are running .38 in unstable it is automatically enabled. You need .38 or later to use this unless you find a backport for an older kernel and manually patch/compile yourself.

[Bulkley]

It's enabled in the Liquorix 2.6.37-0 kernel and probably those since.