High CPU - kjournald & kblockd - nice level

[Brian Hanks]

________________________________________________________________________
> From: Jim Cornette <fc-cornette at sbcglobal.net>
> To: For users of Fedora Core releases <fedora-list at redhat.com>
> Subject: Re: High CPU - kjournald & kblockd - nice level
> Date: Tue, 22 Jun 2004 17:39:25 -0400
> 
> Brian Hanks wrote:
> 
> >Has anyone else experienced what I will call sporadic, jerky X response
> >in FC2?  It seems that any time I have a background process running that
> >is even remotely utilizing any CPU or IO, I have pathetic response in
> >X.  
> >
> >My RH9 box and my FC1 box don't have this issue and they are slower
> >machines with less memory and older disk.  As a test to rule out CPU or
> >chipset specific issues, I've built a completely different machine with
> >FC2.  Both machines exhibited the exact same behavior. 
> >
> >I quite reluctant to make the switch to FC2 without solving this issue. 
> >It's quite annoying to have X become unstable every time I go to compile
> >something in the background.  
> >
> >Hardware Setup #1:
> >Asus A7V600 (VIA Chipset)
> >1 GB RAM
> >Athlon XP 3000+
> >2 Samsung 120 GB SATA drives (RAID1 with LVM2)
> >NVIDIA MX440
> >FC2 fully updated
> >
> >Hardware Setup #2:
> >Asus A7N266-VM (NVidia Chipset)
> >1 GB RAM
> >Athlon XP 2100+
> >2 Maxtor 40 GB ATA drives (RAID1 with LVM2)
> >NVIDIA MX400
> >FC2 fully updated
> >
> >Upon further digging, it looks like kblockd & kjournald
> >are chewing up a ton of CPU.  I'm even noticing it when I don't have
> >large processes running.  It's definitely not as severe, but it seems to
> >be occurring quite regularly. 
> >
> >The one test that I haven't done is to remove LVM2 and RAID1 from the
> >picture.  I wonder if that would eliminate the problem?
> >
> >What exactly is the function of kblockd and kjournald?  Any insight
> >would be greatly appreciated.
> >
> >Thanks,
> >Brian Hanks
> >bhanks at bhanks.com
> >
> >  
> >
> I'm not doing a lot of compiling on my computer. I recall something 
> about the scheduler having priority levels that can be assigned to have 
> processes use a lower or higher priority level.
>  
> I just tried to run
> man nice
> and it came up with an explanation.
> 
> My question about the completion of the compilation. Is the speed of the 
> compilation quicker?
> 
> Jim
> 


It is quicker than my other machines, but not by much; and since it is a
newer, faster machine I expect it to be a bit quicker.  

The other weird thing is that it also happens when I'm doing files
transfers.  If I copy a file from one file system to another or if I scp
a file to the machine, the same thing happens.


-Brian