Re: IO latency - a special case

[Theodore Tso <tytso@mit.edu>]

On Sat, Jun 06, 2009 at 09:14:43PM -0600, Trenton D. Adams wrote:
> I'm back into doing some Java development, and it's happening again.
> I'm running 2.6.30-rc7, and I did a SysReq+T, I hope this is helpful.
> I've attached a txt.gz file, because it's 367K to my
> /var/log/messages.
> 
> The important stuff, I believe, is the Java related stuff.  As a quick
> refresher to this problem, it appears to be related to how my Java IDE
> saves the file, and perhaps something doesn't release the futex right
> away?

Have you checked your memory usage via SysReq-m, or /proc/meminfo or
simply using "free".  I'm seeing a lot of processes in do_page_fault,
which is interesting, especially in the non-Java processes.  

Back in April, your vmstat output didn't show much swapping activity,
but maybe there was more paging activity that didn't show up there?   

> I've also seen these symptoms previously...
> 
> 1. Problem arises, I Ctrl-C the process when I notice the system
> getting really sluggish.
> 2. Start process again, and it locks up the machine for about an hour

What sort of process where you typicalling trying to kill using ^C?

     	     	     	       		   	  - Ted