How to debug high system load?

[Andrew Haley]

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 ?

Andrew.