Negative caching

[Knapp]

On Wed, Jun 17, 2009 at 11:42 PM, Hal Burgiss<hal at burgiss.net> wrote:
> I think I've figured out why recent Ubuntu has such abysmal performance. Very
> cleverly over a period of time, it takes all the free memory and uses it to
> store useless junk that you will never ever use. And then holds on to the
> useless stuff as long as it possibly can. And then you are forced to
> work out of swap. If I leave my system for any length of time, like overnight,
> it is unusable. The delay in simple everyday things like typing in a *text
> terminal* (yes, text!), is ridiculous. Changing workspaces or opening a window is
> insanely slow. Pity the poor soul that has to re-open Firefox. Maybe it takes
> a week to build up that negative cache, but once its got you, you're toast.
> Then its time to reboot or restart X, or lest you get that "watching paint
> dry" feeling for the simplest most everyday things.
>
> atop data:
>
> PRC | sys   0.76s | user   1.70s | #proc    200 | #zombie    2 | #exit      ?
> CPU | sys      7% | user     17% | irq       1% | idle      0% | wait     75%
> CPL | avg1   2.90 | avg5    2.54 | avg15   2.23 | csw     9527 | intr    5228
> MEM | tot  992.4M | free   91.3M | cache 316.9M | buff    3.2M | slab   44.1M
> SWP | tot    2.9G | free    1.4G |              | vmcom   3.2G | vmlim   3.3G
> PAG | scan  10364 | stall      0 |              | swin    4293 | swout    585 (red)
> DSK |         sda | busy    100% | read    1625 | write    608 | avio    4 ms (red)
>
> The quality of life of recent Ubuntu is on a par with Windows 3.1. 8.10 and
> 9.04 should be thrown on the scrap heaps of failed experiments. They suck out
> loud.
>
> I used to brag about never having to reboot a system to maintain usability.
> Not no more. Its the new "normal".
>
> Being a diehard Ubuntu user (home, work and servers at work), its hard for me
> say whether its Linux in general, or just Ubuntu, that totally sucks for a
> desktop. But suck it is.
>
> End rant.
>
> --
> Hal

https://help.ubuntu.com/community/SwapFaq
Scroll to the bottom. Set your swappiness to 10. Is it better now?

-- 
Douglas E Knapp

Why do we live?