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The 2.6.38 kernel's "wonder patch"

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gradinaruvasile
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The 2.6.38 kernel's "wonder patch"

#1 Post by 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.

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Tadeas
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Re: The 2.6.38 kernel's "wonder patch"

#2 Post by 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 :)
Because let’s face it, the unfortunate aspect of software development is that it involves humans. Mewling, disorganized, miserably analog humans. Sometimes they smell bad.

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kevin01123
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Re: The 2.6.38 kernel's "wonder patch"

#3 Post by 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.

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dark_stang
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Re: The 2.6.38 kernel's "wonder patch"

#4 Post by dark_stang »

You guys are making me compile a new kernel...
if (You_Dont_Care_Enough_To_Reasearch_Your_Own_Problems)
return "Why would I?";
else
return Helpful_Response;

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kevin01123
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Re: The 2.6.38 kernel's "wonder patch"

#5 Post by kevin01123 »

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

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hellfire[bg]
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Re: The 2.6.38 kernel's "wonder patch"

#6 Post by hellfire[bg] »

Is this patch enabled by default? Will "kernel.sched_autogroup_enabled=1" work on a stock debian kernel?
...to boldly go where no one has gone before...

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kevin01123
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Re: The 2.6.38 kernel's "wonder patch"

#7 Post by 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
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Re: The 2.6.38 kernel's "wonder patch"

#8 Post by 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/
Debian Bits And Snips
Squeeze, Gnome, amd64, Intel Core i3-530, Geforce GT330

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hellfire[bg]
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Re: The 2.6.38 kernel's "wonder patch"

#9 Post by 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.
...to boldly go where no one has gone before...

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gradinaruvasile
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Re: The 2.6.38 kernel's "wonder patch"

#10 Post by gradinaruvasile »

hellfire[bg] wrote: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
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Re: The 2.6.38 kernel's "wonder patch"

#11 Post by manmath »

dark_stang wrote: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?

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dark_stang
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Re: The 2.6.38 kernel's "wonder patch"

#12 Post by dark_stang »

manmath wrote:
dark_stang wrote: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.
if (You_Dont_Care_Enough_To_Reasearch_Your_Own_Problems)
return "Why would I?";
else
return Helpful_Response;

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sidRo
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Re: The 2.6.38 kernel's "wonder patch"

#13 Post by 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
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Re: The 2.6.38 kernel's "wonder patch"

#14 Post by 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.
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Re: The 2.6.38 kernel's "wonder patch"

#15 Post by Bulkley »

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

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sidRo
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Re: The 2.6.38 kernel's "wonder patch"

#16 Post by sidRo »

if you are running .38 in unstable it is automatically enabled.
isn't enabled by default.

vbrummond
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Re: The 2.6.38 kernel's "wonder patch"

#17 Post by vbrummond »

2.6.38 Configuration File wrote:CONFIG_SCHED_AUTOGROUP=y
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Re: The 2.6.38 kernel's "wonder patch"

#18 Post by gradinaruvasile »

sidRo wrote:
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 ...
Hm. It works for me:

Code: Select all

root@laca-desktop:~# sysctl kernel.sched_autogroup_enabled=1
kernel.sched_autogroup_enabled = 1
root@laca-desktop:~# 
Also i use 2.6.38-2-686-bigmem kernel from the experimental repository. You have to make sure you have a kernel that has this feature compiled in.
In the /etc/sysctl.conf i put this:

Code: Select all

kernel.sched_autogroup_enabled = 1
And it works.

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sidRo
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Re: The 2.6.38 kernel's "wonder patch"

#19 Post by sidRo »

this settings make my system to run more slower.
back to default settings.

Code: Select all

sysctl kernel.sched_autogroup_enabled=0
wonderful patch is a s**t.

vbrummond
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Re: The 2.6.38 kernel's "wonder patch"

#20 Post by vbrummond »

sidRo wrote:this settings make my system to run more slower.
That is actually exactly what it does. It lowers performance in order to have better interactivity when running a job in a terminal that spawns many sub processes. I do not think you would even notice it under most circumstances.
Always on Debian Testing

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