How to debug high system load?

[suvayu ali]

Hi Heinz,

Sorry for the late response.

On Thu, Jul 12, 2012 at 7:31 PM, Heinz Diehl <htd at fritha.org> wrote:
> On 12.07.2012, Suvayu Ali wrote:
>
>> 1. `fsync() on a file': Firefox, Google Chrome, pidgin, emacs
>> 2. `Waiting for buffer IO to complete': jbd2/dm-*
> [....]
>
> Fsync is expensive, but that's the way it is.
>
> If you're using cfq as your scheduler, try this in rc.local:
>
> echo "32" > /sys/block/sda/queue/iosched/quantum
> echo "0" > /sys/block/sda/queue/iosched/slice_idle
> echo "1" > /sys/block/sda/queue/iosched/low_latency
> echo "51200" > /sys/block/sda/queue/nr_requests
>
> Together with this in /etc/sysctl.conf:
>
> vm.dirty_ratio = 10
> vm.dirty_background_ratio = 5
>

I tend not to try things that I don't understand. Could please outline
briefly what the above suggestions do? I would like to understand before
I try them out.

Thanks,

-- 
Suvayu

Open source is the future. It sets us free.