X is very unresponsive while emerging.

bassvandijk

I have compiled my kernel with:
- Preemtible Kernel
- Low latency scheduling
- Control low latency with sysctl

I thought that with these settings I would get a very responsive X.

But when I am emerging something (or doing another CPU intensive task) X just feels very unresponive:

Windows / Menus / Comboboxes that don't draw fast enough, Mouse really jerky, etc...

Usally when I do a lot of X stuff like moving a window or quickly moving my mouse over a menubar, X comes back at full speed...

My question is:
How do I keep X fast enough while emerging something?

(Maybee running emerge with a lower priority?)

Lovechild · Posted: Wed Apr 16, 2003 6:51 pm Post subject:

I have 2.5.67-mm3 and alias emerge="nice -n 10 emerge"

and X runs fine here during emerging, but sound is a bit strange when streaming, man I wish everyone used QoS.

Elm0 · Apprentice Joined: 24 Nov 2002 Posts: 281 Location: UK

This is absolutely 100% a kernel issue (probably

)

I used to use CK sources and experienced the stuttering problems you described. I then moved to WOLK sources and picked the Optimise Scheduler for Desktop setting + preempt + low latency and now X is much more responsive during emerge.

I've heard excellent things from the 2.5 kernel as well, however I would rather not run unstable software, and I had problems getting the IDE-SCSI bridge running last time i tried it.

bassvandijk · Posted: Wed Apr 16, 2003 7:14 pm Post subject:

Gues I'll have to look at another kernel...

Malakin · Posted: Wed Apr 16, 2003 8:00 pm Post subject:

Is your hard drive dma working?

If you have 256M ram or less more ram will help.

Add this to your /etc/make.conf assuming you have a single cpu system and it will stop make from running in parallel:

Disquiet · Posted: Wed Apr 16, 2003 8:16 pm Post subject:

I had this problem with the current gentoo-sources (2.4.20-r2
). r1 worked ok, r2 seems to have some problems. So I emerged gaming-sources and everything is nice again.

hook · Posted: Fri Apr 18, 2003 9:19 am Post subject:

my suggestions:

1. drop the precompiled kernels ...build them from source (vanilla works great for me, but flavours may vary)

2. use nice, as lovechild said

p.s. if you don't know nice try "man nice" or just ask

...it's very usefuly
_________________
tea+free software+law=hook

(deep inside i'm still a tux's little helper)

easykill · Apprentice Joined: 07 Dec 2002 Posts: 230

just for the record 2.4.20-g(aming/entoo) sources, and all the others, are NOT precompiled. They are simply pre-PATCHED with various patches (usually schedulers/hardware things)

You still have to compile them from the source code

hook · Posted: Sat Apr 19, 2003 8:11 am Post subject:

barlad · l33t Joined: 22 Feb 2003 Posts: 673

If you have enabled "Control Low latency with sysctl" then note that Low latency is DISABLED by default. You have to enable it by modifying the sysctl config file. (/etc/sysctl.conf)

On a side note, "nice" must be DISABLED on CK kernels, and most likely on all kernels with the CK patches on. (i.e : preemptible, low latency...). "Nice" is counter-productive with those kernels.
see :
http://members.optusnet.com.au/ckolivas/kernel/#faq

mmealman · Guru Joined: 02 Nov 2002 Posts: 348 Location: Florida

I have this same problem. For awhile I used the Gentoo sources but had some filesystem problems on crashing so I switched to vanilla linux. With the new sources for me my CPU use really shoots through the roof with heavy disk access and my system becomes pretty unresponsive.

I'm sure I'm just missing a kernel compile option or something.

qubex · Posted: Mon Apr 21, 2003 9:52 pm Post subject:

No, I can vouch for the effectiveness of the new scheduler in 2.5.68. It is DEFINITELY 100% effective in battling XFree vs. compilation fatigue. My system can run two compiles, while browsing the web and playing mp3s and experience very little slowdown and almost no stutter. It's really worth checking out, though there are some differences between 2.4 and 2.5 (i.e. ALSA, PCMCIA, etc) that you should watch out for.

If the only problem you are having is stuttering during compile in X, I would tell you with 100% certainty that regardless of your low latency patches in 2.4, the "intellegent" scheduler in 2.5 will help with this issue (and you won't have to "nice" Xfree either..)

Bangz · Posted: Mon Apr 21, 2003 11:40 pm Post subject:

I get this exact same thing!!!

I was about to start a similar thread.

Im running Gentoo Sources r2 kernel.

Whats up with this?

Beekster · Apprentice Joined: 26 Nov 2002 Posts: 268 Location: Sydney

try enabling both low latency and pre-emptive, but without the control low-lat with sys-cntrl, as this defaults to low-lat being off.

I've had weird issues with using _either_ of pre-empt or low-lat by themselves.

Or don't use either option.

crimson · Posted: Tue Apr 22, 2003 3:40 am Post subject:

I had a problem with sys-ctl , and I can't remember the exact error it was causing, but I removed it from my kernel and now it runs just fine.

modal · Apprentice Joined: 02 Oct 2002 Posts: 277

when I run "sysctl -a" i get this:

Bangz · Posted: Thu Apr 24, 2003 4:24 am Post subject:

What is sysctl?

When I changed into Gaming Sources, I enabled Low Latency Sheduling but I kept sysctl with no support cos I wasnt sure.

frogger · n00b Joined: 05 Dec 2002 Posts: 35

sysctl can change kernel options during runtime. If you built your kenel with low latency but without low latency sysctl, you don't have to do anything. Low latency will always be enabled by default.

If you built your kernel with low latency AND with low latency sysctl, low latency is disabled by default, and must be explicitely enabled through sysctl, or by adding "kernel.lowlatency = 1" to sysctl.conf.

aerogems · n00b Joined: 19 Feb 2003 Posts: 30

One other possibility, is I had this problem when using the 4xxx drivers from nVidia. I went back to using the 3xxx series, and the problems went away. Only an occational jerk with the mouse, and even that's been improved using the preempt kernel option.

rj · n00b Joined: 14 May 2003 Posts: 13

What about nice'ing X to make it run faster.. perhaps " nice -10 startx "

is that a good idea?

I compiled gentoo-sources and used mostly whatever was default - i experience some stuttering of sound and mouse jerkiness when emerging... (or anything intensive)