How to debug high system load?

[Suvayu Ali]

On Thu, Jul 12, 2012 at 03:12:00PM +0100, Andrew Haley wrote:
> On 07/12/2012 03:02 PM, Suvayu Ali wrote:
> > On Thu, Jul 12, 2012 at 02:29:54PM +0100, Andrew Haley wrote:
> >> On 07/12/2012 12:00 PM, Suvayu Ali wrote:
> >>> So my question is since CPU usage is already so low, what could be
> >>> driving up the system load? This is bugging me since I also see a
> >>> general sluggishness compared to a much faster system early this year.
> >>
> >> top should show you.  How much time in idle and wait states?
> >>
> > 
> > They are as I would expect, large idle times, and almost no wait time:
> > 
> > top - 15:59:42 up  3:24,  6 users,  load average: 0.74, 0.87, 0.95
> > Tasks: 257 total,   1 running, 254 sleeping,   1 stopped,   1 zombie
> > Cpu0: 2.6%us, 4.0%sy, 0.0%ni, 92.7%id, 0.0%wa, 0.7%hi, 0.0%si, 0.0%st
> > Cpu1: 1.0%us, 0.3%sy, 0.0%ni, 98.0%id, 0.0%wa, 0.3%hi, 0.3%si, 0.0%st
> > Cpu2: 4.3%us, 4.3%sy, 0.0%ni, 91.4%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
> > Cpu3: 0.3%us, 0.0%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
> > Mem:   3843356k total,  3471700k used,   371656k free,   206600k buffers
> > Swap:  6029308k total,        0k used,  6029308k free,  1209176k cached
> 
> That's very odd.  Processes in 'D' = uninterruptible sleep ?
> 

I looked through the entire process list all but 3 were "sleeping", 2
were stopped (I did that in a terminal, a less instance and an
emacsclient instance) and one was zombie (again I know this one, it's
the src-hilite attached to the stopped less instance).

> Andrew.
> 

-- 
Suvayu

Open source is the future. It sets us free.