Re: Finding what is stuck...

From: Jan Knutar
Date: Mon Sep 01 2008 - 22:11:52 EST


On Tuesday 02 September 2008, J.A. Magallón wrote:

> I'm running 2.6.27-rc5-git2 on an Aspire One.
> The system is in general pretty responsive, but sometimes it just
> gets totally stuck. Even the mouse stops.
>
> It looks related to disk (SSD) access, but I'm not totally sure.

Are you hitting swap at all? Does it have swap?

On my N810 tablet there can be a huge slowdown if it starts swapping.
The first time it dips into swap is relatively painless when stuff gets
written out sequentially, but after that when writes are mostly random
the throughput drops to a few kilobytes per second, causing massive
slowdown... The MMC/SD cards hate random write, and I expect SSDs are
no better.

iostat -x -k 10
in a terminal is useful. Check the iowait and util% numbers after/during
slowdown...
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