Desktop Lags under Heavy IO

[pwaller]

My Machine:

pwaller@jupiter ~ $ uname -a
Linux jupiter 2.6.22-suspend2 #2 SMP PREEMPT Mon Sep 3 00:55:46 UTC 2007 i686 Genuine Intel(R) CPU T2500 @ 2.00GHz GenuineIntel GNU/Linux

The lag I'm experiencing is most noticeable when I'm emerging or searching for files using find. Notably it affects the mouse and the keyboard. It makes typing almost impossible because it seems something is registering the key being pressed but not registering the key being released and so I get lots of a single keypress when trying to type.

I'm not really sure where to begin with trying to figure out what is causing this, can somebody recommend a starting point?

Cheers.

P.S. Can someone recommend a way of attaching my Kernel config to this post?

[Ehnvis]

Do you have DMA running on your harddrives? Check with hdparm /dev/hdX or hdparm /dev/sdX, where X is the letter of the drive.

Easiest way to attach the kernel config is to open it up in an editor or view it in some way. Copy the text and paste it to here in code tags.

[tuam]

Easiest way to attach the kernel config is to open it up in an editor or view it in some way. Copy the text and paste it to here in code tags.

And please try to shorten it to reasonable size, e.g. by deleting commented (audio, network, usb) driver lines.

FF,

Daniel

[John R. Graham]

P.S. Can someone recommend a way of attaching my Kernel config to this post?

The best way is to emerge wgetpaste. This utility will establish a temporary place (lasts 30 days) on the web for people to view your config. You can just type

Code: Select all

wgetpaste /usr/src/linux/.config

and wgetpaste will return a URL that you can post to the forums.

- John

[pwaller]

http://rafb.net/p/3v2vGd88.html

[energyman76b]

try cfq as default scheduler.

I had pretty good experiences with it. Better than with AS.

also, please post your dmesg - and maybe explain some of your config choices.
Memory hotplug yes? MSR only module? wtf?

and turn of the generic ide driver, if you are using a chipset driver. Or generic will 'steal' the device - and it is slower.

Also, turn off nmi-watchdog nmi_watchdog=0 as boot parameter. There are reports that it becomes less laggy that way.

do you really need all that scsi-crap? or the stuff in block? or all that fs? btw, if you are using reiserfs, turn of the 'Preempt big kernel log' - it is faster that way. 'Voluntary Preemption' might be better too and '300Hz' instead of 1000. if you are using a laptop, you really don't want 1000Hz, because it sucks down battery juice like a thristy camel water.

Maybe clean up your config. You can't have everything installed you turned on or turned on as module.. your kernel build-time will decrease a lot!

[Sadako]

btw, if you are using reiserfs, turn of the 'Preempt big kernel log' - it is faster that way. 'Voluntary Preemption' might be better too and '300Hz' instead of 1000. if you are using a laptop, you really don't want 1000Hz, because it sucks down battery juice like a thristy camel water.

Any source on this?

I'm not questioning you, it's just that I'm using reiserfs (v3.6) and have "Preempt the big kernel lock" enabled (which is what I presume you meant), and I'd be really interested if those two don't play nice together somehow.

[energyman76b]

btw, if you are using reiserfs, turn of the 'Preempt big kernel log' - it is faster that way. 'Voluntary Preemption' might be better too and '300Hz' instead of 1000. if you are using a laptop, you really don't want 1000Hz, because it sucks down battery juice like a thristy camel water.

Any source on this?

I'm not questioning you, it's just that I'm using reiserfs (v3.6) and have "Preempt the big kernel lock" enabled (which is what I presume you meant), and I'd be really interested if those two don't play nice together somehow.

I have read that on lkml some month ago.. and no, I don't have the link anymore. Reiserfs uses the BKL and the other fs don't. So if reiserfs holds the BKL and it gets preempted, you loose performance.

[astor84]

You don't happen to have an SiS chipset do you? SiS chipsets are notorious for being unable to handle a lot of simultaneous IO.

[pwaller]

No SIS chipset. Sorry for the long delay.. thanks for the advice guys.

I tried some of it out (I haven't switched to the CFQ scheduler yet.)

Here is the latest kernel config, with unused stuff stripped out (but section comments remaining)
http://pastebin.ca/707923

Here is my dmesg output:
http://pastebin.ca/707925

Here is my lspci:
http://pastebin.ca/707928

I tried turning of my scsi stuff but managed to mess everything up. Is there an easy way to maintain multiple kernel configurations installed with the same version of the kernel? I had the problem where I changed stuff and couldn't boot at all because it didn't recognise my hard-disk. I'm using genkernel.. I figure there must be an easy way to do this.

So the options seem to have helped a little, but still when emerging I lose my system almost entirely, and watching a DVD is very jerky.

Thanks in advance guys.

- Peter

[energyman76b]

No SIS chipset. Sorry for the long delay.. thanks for the advice guys.

I tried some of it out (I haven't switched to the CFQ scheduler yet.)

Here is the latest kernel config, with unused stuff stripped out (but section comments remaining)
http://pastebin.ca/707923

Here is my dmesg output:
http://pastebin.ca/707925

Here is my lspci:
http://pastebin.ca/707928

I tried turning of my scsi stuff but managed to mess everything up. Is there an easy way to maintain multiple kernel configurations installed with the same version of the kernel? I had the problem where I changed stuff and couldn't boot at all because it didn't recognise my hard-disk. I'm using genkernel.. I figure there must be an easy way to do this.

So the options seem to have helped a little, but still when emerging I lose my system almost entirely, and watching a DVD is very jerky.

Thanks in advance guys.

- Peter

so you are using slow onboard graphic, your laptop (?) lacks a hpet, I can't find DMA mentioned for your disks, you have two ide drivers loaded instead of one, you are still including douzend of fs you'll never use or need and your are using framebuffer.

only include the ide driver for your chipset
turn this off:
CONFIG_IDE_GENERIC
CONFIG_BLK_DEV_GENERIC
CONFIG_BLK_DEV_VIA82CXXX
you don't have a freaking via-chipset!

turn on this:
Intel PIIXn chipsets support

KICK OUT:
RTC
# Real Time Clock
CONFIG_RTC_LIB=y
CONFIG_RTC_CLASS=y
CONFIG_RTC_HCTOSYS=y
CONFIG_RTC_HCTOSYS_DEVICE="rtc0"

# RTC interfaces
CONFIG_RTC_INTF_SYSFS=y
CONFIG_RTC_INTF_PROC=y
CONFIG_RTC_INTF_DEV=y
CONFIG_RTC_INTF_DEV_UIE_EMUL=y
# Platform RTC drivers
CONFIG_RTC_DRV_DS1553=m
CONFIG_RTC_DRV_DS1742=m
CONFIG_RTC_DRV_M48T86=m
CONFIG_RTC_DRV_V3020=m

turn it off. all of it.

all that scsi-stuff

really.
# DMA Engine support
CONFIG_DMA_ENGINE=y
away!


# Miscellaneous filesystems
CONFIG_SQUASHFS=y
CONFIG_SQUASHFS_EMBEDDED=y
CONFIG_SQUASHFS_FRAGMENT_CACHE_SIZE=3

# Network File Systems
CONFIG_NFS_FS=m
CONFIG_NFS_V3=y
CONFIG_NFSD=m
CONFIG_NFSD_V3=y
CONFIG_NFSD_TCP=y
CONFIG_LOCKD=m
CONFIG_LOCKD_V4=y
CONFIG_EXPORTFS=m
CONFIG_NFS_COMMON=y
CONFIG_SUNRPC=m
CONFIG_CIFS=m
CONFIG_CIFS_XATTR=y
CONFIG_CIFS_POSIX=y

WAAAAAAAH!

almost all kernel-hacking options! Debug = SLOW

And use cfg instead of antipicatory as IO-scheduler.

Your system is jerky, because you load the wrong ide drivers, you slowed it additionally down with debug options you'll never need, increased the kernel size (bigger size = slow) with garbage and you are using a io-scheduler that is HUGE and not really fast.

Build a new kernel, report back if your problem persists.

[pwaller]

Cheers energyman. I will try this out over the next couple of hours and report back

- Pete

[energyman76b]

and excuse me please, if I sound harsh

[Sadako]

and excuse me please, if I sound harsh

You always sound harsh.

[pwaller]

s'ok, your help outweighs your attitude.

I have to say though, I am worried about turning of the SCSI stuff. I think it caused me problems last time. And figuring out exactly what IDE driver to turn off is a pain, too.

Is there any way to keep my old, known-working kernel config around whilst trying out the new one?

[energyman76b]

s'ok, your help outweighs your attitude.

I have to say though, I am worried about turning of the SCSI stuff. I think it caused me problems last time. And figuring out exactly what IDE driver to turn off is a pain, too.

Is there any way to keep my old, known-working kernel config around whilst trying out the new one?

just copy .config somewhere else. Also, I told you exactly which ide driver to turn off and on.

About the scsi stuff: it does not hurt keeping the scsi-disk, scsi-cd, scsi-generic and multi-lun support (the last one is needed for cardreaders). Everything else should be turned of.

and excuse me please, if I sound harsh

You always sound harsh.

look at my avatar. See the annoyed look? That is how I feel 24h a day!

[Sadako]

Is there any way to keep my old, known-working kernel config around whilst trying out the new one?

I think that's what the CONFIG_LOCALVERSION option is there for.

You should definitley disable "CONFIG_IDE_GENERIC" if the VIA82CXXX is the right driver for your board.

Do you have dri, dbe and xv/xvmc working in xorg?

[energyman76b]

Is there any way to keep my old, known-working kernel config around whilst trying out the new one?

I think that's what the CONFIG_LOCALVERSION option is there for.

You should definitley disable "CONFIG_IDE_GENERIC" if the VIA82CXXX is the right driver for your board.

Do you have dri, dbe and xv/xvmc working in xorg?

he does not have via. He has intel. He needs the intel driver. Nothing else.

[Sadako]

and excuse me please, if I sound harsh

You always sound harsh.

look at my avatar. See the annoyed look? That is how I feel 24h a day!

You don't work in tech support, do you?

[Sadako]

A load of nonsense

he does not have via. He has intel. He needs the intel driver. Nothing else.

Ah, I only looked at the kernel config.



My bad.

[energyman76b]

and excuse me please, if I sound harsh

You always sound harsh.

look at my avatar. See the annoyed look? That is how I feel 24h a day!

You don't work in tech support, do you?

almost. I play tech support for a bunch of net-addicted students who don't read the emails in their universities account nor the letters from the landlord (no rent, no net...).

[Sadako]

You don't work in tech support, do you?

almost. I play tech support for a bunch of net-addicted students who don't read the emails in their universities account nor the letters from the landlord (no rent, no net...).

Ouch.

I feel your pain.

[pwaller]

Latest Kernel Config:
http://pastebin.ca/708088

Hey, I seem to have some improvement, but DMA is disabled.

I'm feeling really dumb, I can't figure out what I need to do to turn it on. I've grepped for DMA in the config, but to me it looks like all of the relevant options are on..?

I really appreciate the help guys.

[Sadako]

What does `hdparm -d 1 /dev/hda` actually return, on both the command line and in dmesg?

Oh, energyman76b, I read up on the reiserfs and "Preempt the big kernel lock" thing, and apparently it's only the journalling code which makes use of it, however there isn't much else in the kernel which does use the kernel lock so I've disabled that preemption option.
Thanks for the tip off.

[energyman76b]

dmesg would be helpfull. And you should be able to turn on dma with hdparm (hdparm -d1 -u1 -c1 /dev/hda & the same for your cd drive like hdc..)